ESTIMATION OF SOME GENETIC PARAMETERS IN MAIZE USING LINE × TESTER ANALYSIS A THESIS SUBMITTED TO THE COUNCIL OF THE FACULTY OF AGRICULTURAL SCIENCES UNIVERSITY OF SULAIMANI AS A PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF MASTER OF SCIENCE IN FELD CROPS
(Plant Breeding)
By Dastan Ahmed Ahmed B. Sc. / Field Crops / 2007
Supervised by
Dr. Hussain Ahmad Sadalla Chief of Scientific Researcher
April 2013 A.D.
Nawroz 2712 k.
بسم اه الر ْح َم ِن الرِح ِيم أَلَم تَ ر أَن الله أَنز َل ِمن السم ِ ِ يع فِي اأَ ْر ِ ض ثُم ب ا ي ه ك ل س ف اء م اء َ َ َ َ ُ َ َ َ َ ًَ َ َ َ ْ َ ي ْخ ِرج بِ ِه َزر ًعا م ْختلِ ِ َ ه ي م ث ه ن ا ْو ل أ ا ف ُ ً ُ ص َف ًرا ثُم يَ ْج َعلُهُ ُ يج فَ تَ َرا ُ ُم ْ ُ ُ ْ َ ُ َ َ حطَاما إِن فِي َذلِ ك لَ ِذ ْكرى ِأُولِي اأَلْبَ ِ اب َ ُ ً َ
صدق اللهُ العظيم
[]21
[سورة
الزمر]
Dedication To: My Darling Mother My father memory My gorgeous brothers and my sweet sister My Close friends
Dastan
AKNOWLODGMENT This piece of work will never be accomplished without our God Almighty with His blessings and His power that work within me. I especially want to thank my supervisor Dr.Hussain A. Sadalla, for his sincere help, continuous guidance and precious remarks throughout the work. I would like to express my special thanks to Dr. Aram A. Mohammed and Dr. Ahmad H. Ameen H. Rashid that gave to me this chance. I have a special thanks to my thesis committee members Dr. Mohammad T. Mohammad also Dr. Mohammad A. Hussain In particular, I would like to thank Dr. Sherwan E. Towfiq for his support and valuable remarks and helps istatistical analysis. My thanks for help of the staff of Agricultural Research Center in Qlyasan especially Mr. Sabah for their helps. I would like to thank my mother, as she is simply perfect. I have no suitable word that can fully describe her everlasting love to me, my sister and my brothers for their help, sacrifice and tremendous support. Finally, I am very grateful to my friends of the college faculties especially Shno Osman, Ashti Sleiman and Shadya H. Salh ,Finally thanks for all who helped me during the time of my study. .
Dastan Ahmed Ahmed
SUMMARY This experiment was performed to study the inheritance of some genetic parameters of agronomic characters of maize inbred lines using line x tester analysis method at Qlyasan Research Station, faculty of Agricultural SciencesUniversity of Sulaimani (35° 34' 37" N latitude; 45° 21' 992" E longitude; and 765masl*), at spring season 2011. The crosses of line x tester were done by hand among five lines and three testers, fifteen crosses were obtained. At fall season 2012, twenty three genotypes (fifteen crosses+ three testers+ five lines) were sown in Randomized Complete Block Design RCBD with three replications. The analysis of variance confirmed that the mean squares due to the genotypes were highly significant for all studied characters, the tester parent Talar recorded the highest value for most characters such as plant height, ear height, ear length, No. of rows/ear, No. of grains/row and grain yield t/ha, while the line parent (ZP 434) recorded minimum No. of days to 50% tasseling and silking, the line parent 890 recorded minimum value for most characters such as plant height, ear height, No. of ears/ plant, No. of rows/ear, No. of grains/row and grain yield t/ha, the hybrid {Kr 640 x(Sc(890x3007)}recorded minimum No. of days to 50% tassseling and silking. Maximum No. of rows/ear was recorded by the hybrid (MSI X 3007), while the hybrid {ZP 434 X (Sc(890x3007) } showed maximum values of the characters, ear length and No. of grains/row and the hybrid (890 X (Sc(890x3007) ) recorded maximum values of grain yield, while for 300 grain weight the hybrid (ZP 434 X Talar) gave maximum value, and for No. of ears/plant, the hybrid (Kr 640 X Talar) showed maximum value. The hybrid (890 X 3007) showed the lowest values for the characters No. of ears/ plant, ear length, 300 grain weight and grain yield. While minimum value due to the characters of plant height, ear height, and No. of rows/ear recorded by the hybrid {890X (Sc (890x3007)}.
* masl: meter above sea level. I
Summary The hybrid {Kr 640 X (Sc (890x3007)} recorded maximum negative heterosis values for the characters No. of days to 50% tasseling and silking, the hybrids {890 X (Sc(890x3007)} showed maximum positive heterosis values for plant height, ear length, No. of ears/ plant, No. of grains/ row and grain yield t/h. The variance component due to GCA was larger than SCA for No. of days to 50% tasseling, ear length, No. of rows/ear and 300 grain weight these results made the ratio of σ2g.c.a/σ2s.c.a for these characters to be more than unity confirming the importance of additive-gene effect in the inheritance of these characters, while the average degree of dominance were more than unity for the characters No. of days to 50% silking, plant height, ear height, No. of ears/ plant, No. of grains/ row and grain yield t/ha this explains that characters were under the control over dominance, heritability in broad sense for ear height, No. of rows/ear, 300 grains weight and grain yield t/ha were high, while in narrow sense it was moderate for the characters ear length and high for grain yield, ear length, No. rows/ear ,300 grain weight and grain yield, while for the other characters were low. The contribution of lines were high for days to 50% tasseling, 300 grains weight and No. of ears/ plant, while the interaction between line x tester showed high contribution for the characters days to 50% silking, plant height, and No. of grains/ row.
II
INTRODUCTION Maize (Zea mays L.) is the world leading cereal crop. Where it belongs to tribe maydaea and grass family, Poaceae. It is indigenous to America and was domesticated about 8,000 years ago. Maize does not survive in its wild form probably because of the highly cross pollinated nature (Ram and Singh, 2003). Maize has a remarkable place among cereals and it is used as human food, animal feeding and in industry (Keskin et. al., 2005). Maize is widely cultivated crop throughout the word. In 2010/2011, the world area planted with maize was 162.72 million hectares and the total maize production was 820.02 million tons with the average of 5.04 ton /ha, in the USA alone has the largest area under cultivation of 32.96 million hectares, produceing 316.17 million tons with the average of 9.59 tons /ha (USDA, 2011). In Iraq according to statistics from the Food and Agriculture Organization (FAO) the cultivated area in the whole year (2004) reached up to (145, 142, 563) hectares, producing (705 293 226) tones of grain with the average of (4.859) t / h. As in Iraq the area planted with this crop for the same year reached up to (185,000) hectares, producing (416,000) tons with the average of (2.249) t / h (Arab Organization for Agricultural Development, 2005). It can be concluded that the average of production in Iraq was low compared to world production due to the use of synthetic varieties, un availability of new hybrids, less farmer experience in the cultivation of maize.The main objective of maize breeders is to obtain new inbreed lines and hybrids that will outperform the existing hybrid with respect to a number of traits. Working towards this goal, particular attention is paid to grain yield as the most economically important trait in maize (Vasic et. al., 2001).
1
Chapter One
Introduction
Line x tester analysis is one of breeding strategies to evaluate combining ability effects of genotypes and also to provide information regarding genetic mechanisms controlling traits (Singh and Chaudhary, 1985). Line × tester mating design was developed by Kempthorne (1957), which provided reliable information on the general and specific combining ability effects of parents and their hybrid combinations in applied breeding programs. The design has been widely used in maize breeding by several workers and continues to be applied in quantitative genetic studies in maize due to its significance (Sharma et al., 2004). Line x tester is useful in deciding the relative ability of female and male lines to produce desirable hybrid combinations. It also provides information on genetic components and enables the breeder to choose appropriate breeding methods for hybrid variety or cultivar development programmes. Information on combining ability effects helps the breeder in choosing the parents with high general combining ability and hybrids with high specific combining ability (Dillen, 1975). The aims of this study are: 1- Estimate the general combining ability for parents of maize. 2- Estimate the specific combining ability for Hybrids of First generation. 3- Evaluate the three genotypes this used as testers. 4- Estimate the heterosis as percentage mean deviation of F1's hybrid from mid parental values. 5- Estimate percentage of contribution of inbred line and testers and interference between them in the appeared characteristics.
2
List of content Page No.
Title Summary
I
List of content
III
List of table
V
List of Appendices
VII
List f abbreviation
VIII
Chapter One: Introduction
1
Chapter Two: Review of literature
3
2.1. Line x Tester Analysis
3
2.2. Combining ability
6
2.3. Heterosis
9
2.3. Gene action
12
2.4. Heritability
14
Chapter Three: Materials and methods
17
3.1. Spring Season 2011
18
3.2. Autumn Season 2012
18
3.3. Studied Characters
19
3.4. Statistical analysis
20
3.5. General and Specific combining ability
21
3.6. Proportional Contribution
21
3.7. The component of variation (EMS).
22 III
Page No.
Title 3.8. The average of some genetic parameters
22
3.9. Estimation of phenotypic variation
23
3.10. Heritability
23
3.11. Heterosis
24
Chapter Four: Results and Discussion
26
4.1. No. of days to 50% tasseling
26
4.2. No. of days to 50% silking
29
4.3. Plant height (cm)
33
4.4. Ear height (cm)
36
4.5. No. of ears/ plant
38
4.6 Ear length (cm)
42
4.7 No. of rows/ ear
45
4.8 No. of grains/ row
48
4.9 (300) Grains weight (g.)
51
4.10 Grain yield (t/h)
54
Conclusions
57
Recommendations
57
References
58
Appendices
68
IV
List of tables Table No.
Title
Page No.
1
The pedigree and Sources of the genotypes.
17
2
Analysis of variance according to Line × Tester design. (Kempthorne, 1957)
25
3
The average values of No. of days to 50% tasseling for parents and their hybrids
26
4
Percentage values of heterosis for the hybrids of maize for No. of days to 50% tasseling:
27
5
Estimation of general and specific combining abilities effects, their variances for No. of days to 50% tasseling
29
6
The average values of No. of days to 50% silking for parents and their hybrids
30
7
Percentage values of heterosis for the hybrids of maize for No. of days to 50% silking
31
8
Estimation of general and specific combining abilities effects, their variances of No. of days to 50% silking
32
9
The average values of plant height (cm) for parents and their hybrids
34
10
Percentage values of heterosis for the hybrids of maize for plant height (cm)
35
11
Estimation of general and specific combining abilities effects, their variances for plant height (cm).
37
12
The average values of ear height (cm) for parents and their hybrids
36
13
Percentage values of heterosis for the hybrids of maize for ear height (cm).
37
14
Estimation of general and specific combining abilities effects, their variances for ear height.
38
V
Table No.
Title
Page No.
15
The average values of No. of ears/plant for parents and their hybrids.
39
16
Percentage values of heterosis for the hybrids of maize for No. ears/plant.
40
17
Estimation of general and specific combining abilities effects, their variances for No. of ears/plant.
41
18
The average values of ear length (cm) for parents and their hybrids.
42
19
Percentage values of heterosis for the hybrids of maize for ear length.
43
20
Estimation of general and specific combining abilities effects, their variances for ear length.
44
21
The average values of No. of rows/ ear for parents and their hybrids.
45
22
Percentage values of heterosis for the hybrids of maize for No. of rows / ear.
46
23
Estimation of general and specific combining abilities effects, their variances for No. of rows/ ear.
47
24
The average values of No. of grains/row of parents and their hybrids.
48
25
Percentage values of heterosis for the hybrids of maize for No. of grains/ row.
49
26
Estimation of general and specific combining abilities effects, their variances for No. of grains/row.
50
27
The average values of (300) grain weight for parents and their hybrids
51
28
Percentage values of heterosis for the hybrids of maize for (300) grain weight.
52
VI
Table No.
Title
Page No.
29
Estimation of general and specific combining abilities effects, their variances for (300) grain weight.
53
30
The average values of grain yield for parents and their hybrids.
54
31
Percentage values of heterosis for the hybrids of maize for grain yield.
55
32
Estimation of general and specific combining abilities effects their variances for grain yield.
56
List of Appendix
Appendix
Title
Page No.
1
Mean Squares of variance analysis of genotypes, Line, Testers and their crosses for studied characters
68
2
Average Heterosis of hybrids for the character
69
3
Average analysis of the characters
70
4
The percentage of the contribution of line and testers and interaction line x tester.
71
5
Meteorological data of Sulaimani region for 2012
72
6
Physical and chemical properties of soil at Qilyasan location.
73
VII
List of Abbreviations σ2p
Phenotypic Variance
σ2G
Genetic Variance
σ2e
Mean squares of experimental error or (Environmental Variance)
σ2A
Additive Variance
σ2D
Dominance Variance
GCA
General combining ability
SCA
Specific combining ability
σ2GCA
The variance of general combining ability
σ2SCA
The variance of Specific combining ability
ā
Average degree of dominance
h2.b.s
Heritability in broad sense
h2.n.s
Heritability in narrow sense
MSe-
Revised mean squares of experimental error
VIII
MATERIALS AND METHODS This study was carried out at Qliasan Research Station, Faculty of Agricultural Sciences, University of Sulaimani, 2 km north west of sulaimani city, during the Spring 2011 and Autumn 2012 season, using five inbred lines of maize as lines and three genotypes used as Testers: (inbred line, single cross hybrid and variety). Table 1. The pedigree and Sources of the genotypes:
Testers
Lines
Genotypes No.
Name
Pedigree
Source
1
MSI
Un known
ARDI (DAI)-ARC. Sul
2
ZP 434
Un known
Ministry of Agriculture Bakrajo Research Station
3
Kr 640
IDT
(1DT) Poland
4
890
S 5340
State Board of Agriculture Research- Baghdad
5
3078
creol
State Board of Agriculture Research- Baghdad
6
3007
Erlevo
State Board of Agriculture Research- Baghdad
7 8
Sc(890×3007) Single cross TALAR
Certified variety
17
Local hybrid State Board of Agriculture Research- Baghdad
Chapter three 3.1.
Materials and Methods
Spring Season of 2011
Three testers as (males) were planted on three different planting dates to confirm the presence of pollen grain for a long period, planting dates were (March 17th , March 24th and April 1st 2011), five inbred lines as females were planted on March 24th ,2011. Each genotype was planted in row with 4 meter long. 0.75meter between rows and 0.25 meter within row, two seeds/ hills were planted and thinned after seedling to one plant/ hill. The experiment were Fertilized with the urea (45%N) and Superphosphate (P2O5) as first dose, and second dose as a urea after 45 days from germination. Granular diazinon was used for corn borer control. The crosses between testers and lines were made, each cross was made in three ears as well as the self pollination was made for each inbred line, this was done to obtained sufficient seeds from each cross and inbred line. The ears were harvested, dried and shelled manually and prepared for next season. 3.2.
Autumn Season of 2012 All crosses between the line x testers (15 hybrids) with their parental lines (5
lines + 3 testers) were grown in yield trail experiment Randomized Complete Block design ( R.C.B.D). With three replications was applied, each replication includes 23 treatments (15 hybrid + 5 lines + 3 testers). Seeds were planted in July. 4th, 2012, each treatment was planted in a row (3) m long with (0.75) m between row and (0.25) m within rows. All cultural recommended practices were performed according to the plant requirements.
18
Chapter three
Materials and Methods
3.3. Studied characters Data were recorded from five randomly plants/ row from each experimental unit for all studied characters except for days to 50% tasseling and silking. The mean of five plants for each replication was used for statistical analysis. 3.3.1. Days to 50% tasseling The number of days from sowing up to the day on which 50% of the plants showed silk emergence was recorded as days to 50% tasseling.
(nevado and
Cross, 1990). 3.3.2. Days to 50% silking The number of days from sowing up to the day on which 50% of the plants showed pollen shedding was recorded as days to 50% silking. (nevado and Cross, 1990). 3.3.3. Plant height (cm) Is the height of plant in (cm) from the soil surface to the base of tasseling. (Johnson, 1975). 3.3.4. Ear height (cm) Is the height of plant in (cm) from the soil surface to the base of upper ear. (Johnson 1975). 3.3.5. No. of ears/plant Number of ears per plant was counted and the average was recorded. 3.3.6. Ear length (cm) Length of ear was measured and recorded from base to tip of ear. 3.3.7. No. of rows/ ear Number of row / ear was counted and recorded. 3.3.8. No. of grains / row Number of grains/row was counted and the average was recorded. 19
Chapter three
Materials and Methods
3.3.9. 300- grain weight (g) The weight of 300- kernel was recorded at 15% moisture content. 3.3.10. grain yield (t/ha) Calculated as the total grains weight in one hectare.
3.4. Statistical analysis All recorded data were examined according to analysis of variance procedures (ANOVA). The linear model utilized for individual analysis and least significant differences (LSD) at 5% significant level were calculated to evaluate the means.
Yij = µ + Ʈi + ρj + Ԑij Where:
Yij:
The value of observation belongs to experimental unit designated
µ : The general mean value,
Ʈi : The value of the actual effect of treatment "i", ρj: The value of the actual effect of block "j" and Ԑij:
The value of the actual effect of experimental error belongs to the
observation designated as treatment "1" in the block "j". Ԑij ~ NID (0, σ2E) Line X tester analysis was performed according to (Kempthorne, 1957) to estimate the general and specific combining
20
Chapter three
Materials and Methods
abilities, genetic component of variance, and proportional contribution of line, testers and the interaction between line x testers variances.
3.5. General and specific combining abilities: The effect of general combining ability of Line parents and Tester parents were calculated using the following equation: Line
( i) = ȳ i.. _ ȳ …
Testers
( i) = ȳ.j. _ ȳ …
The effects of specific combining ability of hybrids were calculated by using the following equation: (Ŝij) = ȳ ij. ˗ ȳ i.. ˗ ȳ .j. + ȳ… 3.6.
Proportional contribution:
The estimation of the rate of participation for each of the mothers, tester and integration between them in each character were found by using the following equation: Contribution of line
=
Contribution of tester
=
Contribution of line x tester =
21
Chapter three
Materials and Methods
3.7. The components of variation: The expected (EMS) of genetic parameters were estimated as following: σ2L =
=½ σ2A
σ2t =
= ½ σ2A
σ2 L x T=
3.8. The average of some genetic parameters: The average of same genetic parameters was calculated as following equation: σ2A=
+
σ2A = σ2t + σ2l σ2 g.c.a = ½ σ2A σ2 lxt =σ2D σ2D = σ2lxt σ2 s.c.a = σ2D σ2 E = σ2e = Mse
22
Chapter three
3.9
Materials and Methods
Estimation of phenotypic variation The phenotypic variation was estimated by following equation:
σ2P = σ2l+ σ2t + σ2lxt+ σ2e =σ2A+ σ2D+ σ2e = σ2G+ σ2e As: σ2E= environmental variance σ2D= Dominance genetic variance σ2A= Additive genetic variance σ2G = Total genetic variance σ2P= Phenotypic variance (genetic and environmental)
3.10. Heritability Heritability in broad and narrow sense were estimated depending on the variance of general and specific combining abilities, and the variance of experimental error according to Singh and Chaudhary, (1985), equation was used to calculate: a- Heritability in Broad Sense: h2.b.s =
b- Heritability in Narrow Sense: h2.n.s =
23
the following
Chapter three
Materials and Methods
c- Average Degree of Dominance ( ) = If: ā= Zero
Indicates non dominance.
ā=1
Indicated complete dominance
ā<1
Indicated partial dominance
ā> 1
Indicated over dominance
a. Heterosis: It was estimated as percentage deviation of F1 hybrid from mid parental value: Heterosis (H) % = Where: : Mean of first generation M.P: mid parental value
Where: M.P = P1: Parent no. 1 P2: parent no. 2
24
Chapter three
Materials and Methods
Table 2. Analysis of variance according to Line x Tester design. (Kempthorne, 1957) S.O.V
d.f
Replication
r-1
MSr
Genotypes
g-1
MSg
Parents
P-1
MSp
Crosses
Lt-1
MSc
Parent vs crosses
1
Lines
L-1
MSI
σ2e+rt σ2l
Testers
T-1
MSt
σ2e+rl σ2t
Line x Tester
(L-1)(T-1)
SSc- SSl- SSt
Ms(lxt)
σ2e+r σ2lxt
Error
(r-1)(g-1)
SST-SSr-SSg
MSe
σ2 e
Total
rg-1
R= Replication
L= Inbred line
S.S.
M.S
SSg- SSp- SSC
E.M.S.
MSp.Vs.c.
∑yijk2
T= Tester
25
G= Total number of genotypes
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and L. Tugut. 2003. Heterosis and combining ability for yield component and fiber quality parameters in half diallel cotton (G.hirsum L.) population. Turkish. J. Agri. For. 27:207-212.
Beck, D., S. Vasal and J. crossa. 1990. Heresies and combing ability of CIMMYTS tropical early and intermediate Maize germplasm. Maydica, 35:279-285. Birchler, J. A., D. L. Auger, and N. C. Riddle. 2003. In search of the molecular basis of heterosis. Plant Cell 15:2236–2239. Bocanski, J., Z. Sreckov, A. Nastasic. 2009. Genetic and phenotypic relationship between grain yield and component of grain yield of Maize (Zea mays L.). genetika, 41(2), 145-154. Chaudhary, A. K. Chaoudhary. 2002. Genetic studies in some crosses of maize (Zea mays L.).J. Res. (BAU), 14(1): 87-90. Chen, Z.J., 2010. Molecular mechanisms of polyploidy and hybrid vigor. Trends Plant Sci. 15: 57–71. Comstock, R.E. and Robinson. 1948. The components of genetic variance in population of bi parental progenies and their uses in estimating the average degree of dominance, Biometrics 4,254-262. Desai, S. A. and M. Singh. 2001. Combining ability studies for some morphological, Physiological and biochemical traits related to drought tolerance in maize. Indian J. Genetic. And plant Breeding. 61:34-36. 59
References Dhabholkar A., G. S. Lal, R. C Mishra and N. B. Barche. 1989. Combining ability analysis of resistance of sorghum of shootfly. Ind Jour .of Gen. 49, 325-330. Dillen, B. S., 1975. Application of partiall diallel crosses in plant breeding. A review, crop improvement. 2:1-7. Doerksen, T., Kannenberg L. and L. Lee. 2003. Effect of recurrent selection on combining abilitry in maize breeding populations. Crop Sci.,43: 16521658 Dubey, R. B., V. N .Joshi and N. K. Panadiya. 2001. Heresies and the combing ability for quality, Yield maturity traits in conventional and nonconventional hybrids of maize(Zea mays L.).Ind. J. Genet. Plant Breed. 61:353-355. El- Diasty, M, 2007.Genetiv evaluation of hybrids in relation to their parents in intra specific cross in Maize. M.Sc. Thesis, Agron, Department, faculty of Agri. Mansoura Univ. Egypt. El- Moselhy, A. A., 2005. Comparison of some different Maize genotypes to cultivation under moisture stress condition. Ph. D. Thesis, Agron, Department, faculty of Agri. Mansoura Univ. Egypt. El- Shenawy, A. A., H. E.Mosa and A. A. Motawei. 2009. Combining Ability of crosses and Stability Parameters of their Single Crosses. J. Agri. Res. 35(4). Falconer, D. C., 1981. An introduction to quantitative genetics. and edition, Longman, New York, 67-68. Falconer, D. S. and T. F. C. Mackay. 1996. Introduction to quantitative genetics. 4th ed. London: Longman, pp: 464. FAO statistics (2006): www.fao.org.
60
References Flint-Garcia S. A, Buckler E. S, Tiffin P., Ersoz E. and Springer N. M. 2009. Heterosis Is Prevalent for Multiple Traits in Diverse Maize Germplasm. PLoS ONE 4: e7433. doi:10.1371/journal.pone.0007433. Food the Agriculture Organization (FAO). 2004. quoted from (Hussain, Z. M. M. 2006. The critical period to weed control in the maize crop. Sc. Thesis, field crop department. College of Agri, Univ. of Baghdad. (In Arabic). Geetha K., 2011. Heterosis in maize (Zea mays L.). Agri. Sci. Dig., 21: 202-203. Griffing, B., 1956. A gene razed treatment of the use of diallel cross in quantitative inheritance. Heredity 10, 31-54. Hallauer, A. R., M. J. Cerena, J. B., and M. Filho. 2010. Quantitative Genetic in Maize Breeding. Hand book of plant Breeding 6, DOI 10.1007/978-14419-0766-0_1, Springer Scince + Business Media, LLC. Hallauer, R. A., 1997. What have
we learn, what have we done, where are we
headed: In. The Genetic and Exploitation of heterosis in Crops. An International Symposium. CIMMYT. Hochholdinger, F., and N. Hoecker. 2007. Towards the molecular basis of heterosis. Trends Plant Sci. 12:427–432. Iqbal, M. K. K., H. Rahman, I. H. Khalil, H. Sher and J. Bakht. 2010. Heterosis for morphological traits in subtropical maize. Maydica, 55:41-48. Johanson, G. R. 1975. Relationships between yield and seven yield component in aset of maize hybrids. Crop Sci. 13; 649-651. kaczmarek. Z. H k., and Tuczkiewice. 1986. Analysis of line xtester progenies compared in orthogonally supplemented efficiency balanced in complete block design. Biometrical. J.28: 45-58. Kara, S. M., 2001. Evaluation of yield and component in inbred maize lines. I Heterosis and Line X tester analysis of combining ability. Turkish Journal of agricultural Forestry, 25: 383-391. Kempthorne, O., 1957. An introduction to genetic statics. Johan wily and sons, Inc. New York, USA.468-473. 61
References Keskin, B Yalmaz, I.H, and Arvas, O. 2005. Determination of Some Yield characters of grain corn in eastern Anatolia region of Turky. J. Agro., 4(1): 14-17. Konak, C., U. A. Basal and H. N. serter, 2001. Combining ability and hetrotic effect in breeding nursery population of maize (Zea mayse. L.) and its importance inbreeding PBA, 46(1):26. Kumar, P., and S. C. Gupta. 2003. Genetic analysis in maize (Zea mays L.). J. Res. Birsa Agric. Univ. 15(1): 107-110. Kumar, R., M .Singh, M. Narwal and Sharma. 2005. Gene effect of grain yield and its attributes in maize. Natural J. Plant Inprovement, 7: 105-107. Li-Jizhu, W. Shang, G. Baogui and T. wieguang. 2004. Genetic study of ear kernel character of maize. J.of jilin Agri .Univ. chang chaun. 26 (6):494-498. Liu, W., and M. Tollenaar. 2009. Physiological mechanisms underlying heterosis for shade tolerance in maize. Crop Sci. 49:1817–1826. Mahmood Z., R. M. Shahid, A. Raheel and R. Tariq. 2004. Heritability and Genetic Advance Estimates from Maize Genotypes in shishi lusht a Valley of Kaakurm. Int. J.of Agri. & Bio..pp: Mahmood Z., S. Malik, R. Akhtar and T. Rafique. 2004. Heritability and Genetic Advance Estimates from Maize Genotypes in Shishi Lusht a Valley of Krakurm.
Int. J. of Agri. & Bio. 1560-8530, 5:790-791.
http://www.ijab.org Malik, S. I., H. N. Malik, N. M. Minhas, and M. Munir. 2004. General and specific combining ability studies in maize in deallel crosses. Int. J. of Agri. & Bio. 6(5): 856-859. Mohammad, S. M., 2001. Estimation of Some Genetic Parameters for Half Diallel Cross in Corn (Zea mays L.) in Kurdistan. M.Sc.Thesis, College of Agri. Univ. of Salahaddin. (In Arabic).
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References Mohammad, S.M., 2005. Reciprocal Diallel Crosses and estimation of Genetic Component of Maize (Zea mays L.) in Kurdistan. Ph. D. Dissertation, College of Agri. Univ. of Salahaddin. (In Arabic). Mostafavi, K., R. Chogan, M. Taeb, E. M. Heravan and M. Bihamta. 2008. Investigation of combining ability in Iranian corn inbred line (Zea mays L.) using diallel cross designs Iranian J. Argron., 4 (2):5-21. Muhammad, Y. and S. Muhammad. 2002. Estimates of heritability for some quantitative characters in maize Int.J. Agric.and Biology. 4:103-104. Mustafa N. R. and H. A. Sadalla. 2008. Estimation of Combining Ability and Genetic Parameters Using (Line x Tester) Method in Maize Inbred Lines (Zea mays L.). Zanco J. and pure Applied Sci. / Salahaddin Univ. Salahaddin-hawler. Vol. 20.No. 3. Mustafa, N. R., 2008. Three genotypes As a Testers for Combining Ability in Inbred Lines of Maize (Zea mays L.) in Kurdistan. M.Sc.Thesis, College of Agriculture, University of Salahaddin. (In Arabic). Narro l., S. pandey, J. Crossa, C. D. Leon and F. Salazar. 2003. Using Line x Tester Interaction for the formation of Yellow Maize synthetics Tolerance to Acid Soils. Published in Crop sci. 43:1718-1728. Netaji, S. V. S. R. K., A. L. Styanarayana, E. and Suneetha, V., 2001. Heterosis studies for yield and yield component character in maize ( Zea mays L.) The Andora Agricu. J., 47: 39-42. Nevado, M. E and H. Z. Cross.1990. Diallel analysis of relative growth rates in maize synthetics. Crop Sci. 30: 549-552. Ojo, D. K., O. A. Omikunle, O. A. Oduwaye, M. O. Ajala and S. A. Ogunbayo. 2006. Heritability, Character Correlation and path analysis among Six Inbred- lines of Maize (Zea mays L.). J. of Agri. Sci.2 (3): 352-358. Ojo, G. O. S., D. K. Adedzwa, and L. L. Bello. 2007. Combining ability estimates and heterosis for grain yield and yield components in maize (Zea mays L.). J. Sustainable Development in Agric. Environment 3:49-57. 63
References Olaoye, G. O., B. Bello, A. K. Ajani and T. K. Ademuwagun. 2009. Breeding for improved organoleptic and nutritionally acceptable green maize varieties by crossing sweet corn (Zea mays saccharata): Changes in quantitative and qualitative characteristics in F1 hybrids and F2 populations, Journal of Plant Breeding and Crop Science Vol. 1(9). pp. 298-305. Om, P., P. Shanthi, E. Satyanarayana, and R. Saikumar. 2006. Studies on genetic variability exploitation for quality and agronomic Ann. Agri. Res., 27(2):147:153. Prakash, S. and D. K. Ganguli. 2004. Combining ability for various yield component characters in maize (Zea mays L.). J. Res. Birsa Agric. Univ., 16(1): 55-60. Pshdary, D. A. A. 2011. Analysis of Full Diallel Cross in Mize (Zea mays L.). In Kurdistan. Ph. D. Dissertation, College of Agri. Univ. of Sulaimani. Rafiq C. M., R. Muhamad, H.
Amir and A. Muhammad. 2010. Studies on
Heritability, Correlation and Path analyses in Maize (zea mays L.). J. Agri. Res., 48(1). Rafique M., A. Hussain. T. Mahmood, A. W. Alvi and M. B. Alvi. 2004. Heritability and interrelationships among grain yield and Yield Component in Maize (Zea mays L.).Int. J. of Agri. & Boil. 1560-85306-1113-1114. Ram, H.H and H.G. Singh. 2003. Maize. In: Crop Breeding and Genetics. Pp. 105109. Kalyni publishers, India. Rawlings, J. O., Thompson, D. L., 1962. Performance level as criterion for choice of tester, Crop Sci. 2:217-220 Rezaei, A., 2004. Estimate of heterosise and combining ability in maize (zea mays L.), Genetic Variation for plant breeding, 395-398, Vienna. Robinson, R. A.
2004. Amateur plant breeder s hand book. Share book
Domination-445 proves line. Fergus Ontario- Canada NIM2N3. 64
References Sadalla, H. A., N. R. Mustafa, S. A. Kakarash. 2012. Pollen Source Effect on Maize kernel Oil Concentration). Zanco j. and pure Applied Sciences/ Salahaddin Univ. Salahaddin-hawler. Vol. 24. No. 2. Sanvicente, F. M., A. Bejavano, C. Martin, and J. Crossa. 1998. Analysis of diallel crosses among improved tropical white endosperm maize population. Maydics, 43(2):147- 153. Semel, Y., Nissenbaum J., N. Menda, M. Zinder, U. Krieger, N. Issman, T. Pleban, Z. Lippman, A. Gur and D. Zamir. 2006. Over dominant quantitative trait loci for yield and fitness in tomato. Proc Natl Acad Sci USA 103: 12981–12986. Shahnejat-Busheri, A. A., S. torabi, M. Omidi, and M. R. Ghannadha. 2005. Comparison of Genetic and morphological distance with heterosis with RAPD marker in hybrid of the barley, Int. J. of Agri. and Bio. 7(4):592595. Shahwani, M. N., Salarzai, A., Bangulazi, B. A., shawani, M. A. and Hengl, N. M., 2001. Hybrid vigor for grain yield and its components in maize crosses, Sahrad Journal of agriculture, 17:571-576. Sharief, A. E., S. E. El-Kalla, H. E. Gado, H. A. E. Abo-Yousef. 2009. Heterosis in yellow maize. Aust. J. Crop Sci. 3: 146-154. Sharma S, Narwal MS, Kumar R, Dass S (2004). Line x tester analysis in maize (Zea mays L.). Forage Res 30: 28-30 Sing RK, Chaudhary BD (1979) Line × tester analysis. I: Biometrical methods in quantitative genetics. New Delhi: Kalyani publishers, India. Shawarf, I. I. S. and L. R. Baker .1981.Combining ability and genetic variance of GxHf1 hybrid parthenocarpic yield in genoecious pickling cucumber for once over mechanical harvest J. Amer. Soc. Hort. Sci.106: 360-370. Shull, G.H., 1908. The composition of a field of maize. Am. Breeder Assoc. Rep. 4: 296–301. 65
References Sinawat, V., J. pandy, P. Lipner, P. Stamp and Y. Frachebuod. 2004. Effect of heat stress on photosynthetic apparatus in maize (Zea mays L) grown at control or high temperature. Environ. Environ.Exp. Bot., 52: 123-129. Singh P. K., A. K. Roy. 2007. Diallel analysis of inbred lines in maize (Zee mays L.). Intl. J. Agri. Sci. 3: 213-216. Singh, P., 2004. Essentially of plant breeding. Section -1.Introductory topics. P. 86-87. Singh, R. K. and B. D. chaoundary.1979. Biometrical methods in quantitative genetic analysis. New Delhi, kalyani publisher. Singh, R. and B. D.
chaudhary. 1985. Biometrical Methods in Quantitative
genetic analysis .R,V. ed pp318,kalyani publishechers, ladharana,New Delhi.India. Singh, S. P. and A. B. joshi. 1966. Line x tester in relation to breeding for yield in linseed. Indian G.of Genetic plant breed.26:177-194. Soengas, P., B. Ordais, R. A. Malvar, P. Revilla, and A. Ordais. 2003. Heterotic patterns among fl int maize populations. Crop Sci. 43:844–849. Sprague, G. F., and L. A. Tatum. 1942. General versus specific combining ability in single crosses of corn. J. Amer. Soc. Agron. 34: 923-32. Sprague, G. F., 1966. Quantitative genetics in plant improvement. P.315-343. In: plant breeding, K J. Frey (ed). Lower State Univ. press, Ames. Srdić, J., Z. Pajić, and S. S. Mladenović-Drinić. 2007. Inheritance of maize grain yield components. Maydica 52(3): 261-264. Sujiprihati , S., G. B. Saleh, E. S. Ali. 2003. Heritability, performance and correlation studies on single cross hybrids of tropical maize. Asian J. Plant Sci. 2: 51-57. Sumathi, P., A. Nirmalakumari, and K. Mohanraj. 2005. Genetic variability and traits interrelationship studies in industrially oil rich CIMMYT lines of maize (Zea mays L.). Madras Agric.J. 92 (10-12): 612-617. 66
References Sundararajan and P. S. kumar. 2011. Studies on combining ability through Line x testers analysis Maize (Zea Mays L.). plant Archives Vol. 11 No.1.pp,75-77. Tabassum, M. I., M. Saleem, 2005. Genetic trend of maize (Zee mays L.) under normal and water stress conditions. Pak. J. Boil. Sci. 8: 571-580. Thiemann,
A., M. Stephanie and S. Stephan. 2009. Heterosis of plant: Manifestation in early seed development and prediction approaches to assist hybrid breeding. Chinese Science Bullet in. Vol. 54, no. 14: 2363-2375.
Uddin, M. S., F. Khatun, S. Ahmed, M.R. Ali and S. A. Bagum, 2006. Heterosis and Combining ability in Corn (Zea mays L.). Bangladesh J. Bot., 35(2): 109-116. USDA, United States Department of Agriculture. Foreign Agriculture Service 2011. Corn Area, Yield and production. http//www.fas.usda.gov . Vasic, N., M. Ivanovic, L. Peternell, D.Jockovic, M.Stojakovic, J. Bocanski (2001). Genetic relationships between grain yield and yield components in a synthetic population and their implications in selection. Acta Agronomica Hungarica, 49 (4), 337–342. Wang, X. H., C. D. Zhang, B. Li, yan He, J. L, S. Wag. 2007. Relationship Between Differential Gene Expression erosis During Ear Development in Maize (Zea mays L.) J. of Gen. and Geno. vol 34(2), pp 160-170. Zaffer, G., 1999. Comparative studies on estimation of genetic variances in maize ph. D thesis SKUAST-K, pp: 141.
67
RESULTS AND DISCUSSION 4.1. Number of days to 50% tasseling: Table (3) and appendix (1) confirmed the presence of highly significant differences between genotypes due to the character No. of days to 50% tasseling. The line parent 2 found to be earliest in requiring days to 50% tasseling by 50.0 days, followed by tester parent 8 which required 52.6 days, while the line parent 1 was the latest in No. of days to 50% tasseling which was 58.6 days. These differences between parental values affected significantly on their hybrids. Regarding the hybrids values both hybrids 2x6 and 3x7 required minimum No. of days to 50% tasseling in which required only 49 days, followed by 2x7 with 49.3 days, the hybrid 1 x7 required maximum No.of days to 50% tasseling with 56.3 days and followed by hybrid 5x6 which required 54 days, result agree with (Mustafa, 2008, Barakat and Ibrahim, 2006). Table 3. The average values of parents and their hybrids for the character No. of days to 50% tasseling. Testers 6
7
8
Mean of lines
1
53.6
56.3
51.6
58.6
2
49.0
49.3
50.3
50.0
3
51.6
49.0
50.6
55.6
4
50.3
51.6
50.3
55.0
5
54.0
51.3
51
54.6
Mean of testers
53.6
53.6
52.6
Lines
G.M
52.3
L.S.D
3.67
26
Chapter Four
Results and Discussion
Table (4) showed the heterosis values for the character No. of day to 50% tasseling, estimated as percentage of Fl'S deviation from the mid parental values. All hybrids gave negative heterosis values with the exception of the hybrid 1x7 where produced positive heterosis value. Maximum negative heterosis value was 10.2% exhibited by the hybrid 3x7 and followed by the hybrids 4x8 and 4x6 with (9.5 and -7.3)% respectively. The hybrid 1x7 showed positive heterosis value with 0.3%, the negative values indicated that these hybrids required less No. of days to tasseling. While the positive value indicated the delay of this hybrid in No. of days to 50% tasseling. Positive and negative heterosis values were also exhibited by (Mohammad, 2005; Al- Janaby, 2003 and Al- Falahy, 2002). Table 4. Percentage values of heterosis for the hybrids of maize for No. of days to 50% tasseling: Heterosis Testers 6
7
8
1
-4.4
0.3
-7.1
2
-5.4
-4.8
-1.9
3
-5.4
-10.2
-6.9
4
-7.3
-4.9
-9.5
5
-0.1
-2.0
-4.8
Lines
S.E= 0.79
27
Chapter Four
Results and Discussion
Table (5) showed genetic analysis for the character No, of days to 50% tasseling. It was shown that the line parent 2, 3 and 4 produced negative values of GCA with (-1.800, -0.91 and -0.578) respectively, indicating the reduction in No. of days to 50% tasseling in their hybrids. While the parents 1 and 5 showed positive GCA values with 2.533 and 0.756 respectively, regarding the values of GCA effect due to tester parents, the parents 8 showed negative values -0.556 while the parents 6 and 7 with 0.378 and 0.178 showed positive GCA effect values. Some genetic parameters also represented in table (5), the variance component due to GCA was larger than SCA, making the ratio σ2gca/ σ2sca became more than unity 1.35, indicating the importance of additive-gene effect in controlling the inheritance of this characters. These results were confirmed by degree of dominance value which was less than unity (0.85), and heritability in broad sense was 0.37 while in narrow sense it was 0.27 these results confirmed
that the
hybridization method can be applied for improving this character. Similar results were obtained by the researchers (Mustafa, 2008; Sumathi et. al., 2005 and Choudhary and Choudhary, 2002). Appendix (4) shows that the lines were contributed by a high ratio at showing days to 50% tasseling and reached 60.68%. While testers and line x tester were contributed (4.29%) and (35.03%) respectively for inheritance of this character.
28
Chapter Four
Results and Discussion
Table 5. Estimation of general and specific combining abilities effects, and some genetic parameters for No. of days to 50% tasseling: S.C.A Testers 6
7
8
G.C.A for lines
1
-0.60
-0.60
-1.67
2.533
2
-0.93
-0.93
1.33
-1.800
3
0.84
0.84
0.78
-0.911
4
-0.82
-0.82
0.11
-0.578
5
1.51
1.51
-0.56
0.756
G.C.A For testers
0.378
0.178
-0.556
Lines
S.E
Lines
Testers
0.744
0.576
Hybrids 1.288
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
1.35
2.20
0.81
0.85
0.37
0.27
4.2. No. of days to 50% silking: Table (6) and Appendix (1) exhibited of highly significant differences between genotypes due to the character No. of days to 50% silking. The line parent 2 was found to be the earliest in requiring days to 50% silking with 56.3 days. While the parent line 3 was the latest in requiring days with 63.00 days. The differences between parental values affected significantly on their hybrids. Regarding the hybrid values, the hybrids 3x7 recorded minimum value of days to 29
Chapter Four
Results and Discussion
50% silking with 50.3 days. While the hybrid 5x6 exhibited the maximum value of days to 50 % silking whith 60.0 days. Significant differences were also reported previously by (Al- Azawy, 2002 and Al- Janaby 2003). Table 6. The average values of No. of days to 50% silking for parents and their hybrids. Testers 6
7
8
Mean of lines
1
57.0
57.0
55.6
61.6
2
52.0
52.0
59.3
56.3
3
52.0
50.3
58.6
63.0
4
54.6
58.6
57.0
60.3
5
60.0
53.6
58.3
59.3
Mean of testers
57.0
62.3
56.6
Lines
G.M
57.11
L.S.D
5.1694
Table (7) showed the heterosis values for the character No. of day to 50% silking, estimated as percentage Fl'S deviation from the mid parental values. All hybrids gave negative heterosis values with the exception of the hybrids 2x8, 5x8 and 5x6 in which produced positive heterosis values. Maximum negative heterosis values were -19.7% exhibited by the hybrid 3x7, followed by the hybrid 3x6 with 13.3%. The hybrid 2x8 with 5.0 % showed maximum positive heterosis value, the negative values indicated that these hybrids required less No. of days to silking, and the positive value indicated delay in the characters to No. of days to 50% silking. Positive and negative heterosis values were also exhibited by (Pshdary, 2011; Geetha, 2011; Mustafa, 2008; Mohammad, 2005 and Netaji et. al., 2001). 30
Chapter Four
Results and Discussion
Table 7. Percentage values of heterosis for the hybrids of maize for No. of days to 50% silking. Heterosis Testers 6
7
8
1
-3.8
-7.9
-5.9
2
-8.2
-12.3
5.0
3
-13.3
-19.7
-2.0
4
-6.9
-4.4
-2.4
5
3.1
-11.8
0.6
Lines
S.E= 1.61 Table (8) showed genetic analysis for the character No. of days to 50% silking, The line parents 2 and 3 produced negative GCA effect values with -1.133 and -2.133 respectively, indicating the reduction in No. of days to silking in the hybrids precipitated by them, while the line parents 1, 4 and 5 showed positive GCA effect values with 0.756, 0.978 and 1.533 respectively. Regarding the testers parent, it was shown that, the testers parent 6 and 7 showed negative values with 0.533 and -1.467 respectively while tester parent 8 recoded positive value of GCA with 2.00. Some genetic parameters also represented in table (8), the variance component due to SCA was larger than GCA, making the ratio σ2gca/ σ2sca became less than unity 0.35, indicating the importance of non additive gene effect in controlling the inheritance of characters, this result was confirmed by degree of dominance value which exceed the unity 1.68, and heritability in broad sense was 0.48 while in narrow sense it was 0.20 this results confirmed the importance of hybridization method for improvement this character . These results were in agreement with the results of the previous researchers (Sadalla et al., 2012; Rafiq 31
Chapter Four
Results and Discussion
et. al., 2010; El- shenawy et al., 2009; Sujiprihati et al,. 2003; Desai and Singh, 2001; Sanvicent et. al., 1998). According to appendix (4) the contribution of proportion of lines x testers interaction for days to 50% silking was higher and reached (54.45%) while line and tester were contributed (22.12%) and (24.43%) respectively for each showing this character. Table 8. Estimation of general and specific combining abilities effects, and some genetic parameters for No. of days to 50% silking. S.C.A Testers 6
7
8
G.C.A for lines
1
0.98
1.91
-1.67
0.756
2
-1.47
-1.20
1.33
-1.133
3
-1.13
-1.87
0.78
-2.133
4
-1.58
3.36
0.11
0.978
5
3.20
-2.20
-0.56
1.533
G.C.A For testers
-0.533
-1.467
-0.556
Lines
S.E
Lines
Testers
Hybrids
1.048
0.569
1.272
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
0.35
3.89
5.51
1.68
0.48
0.20
32
Chapter Four
Results and Discussion
4.3. Plant height (cm) Table (9) and Appendix (1) confirmed the presence of highly significant differences between genotypes for the character plant height. the maximum plant height for testers values were recorded by the tester parent 8 with 151.0 cm, while the lowest plant height value was exhibited by tester parent 7 with 118.6 cm and the line parent 2 recorded maximum value for plant height with 144.0 cm, while line parent 4 recorded minimum value for plant height with 95.8 cm, these differences between parental values affected significantly on their crosses values. Regarding hybrid values, maximum plant height was 152.2 cm was recorded by the hybrid 5x8, while the hybrid 4x7 with 125.3 cm showed the lowest plant height value. Results agree with (Sundararajan and Kumar, 2011; Baracat and Ibrahim, 2006). Table 9. The average values of plant height (cm) for Lines and testers, and their hybrids. Testers 6
7
8
Mean of lines
1
149.6
135.2
136.4
133.2
2
146.6
148.3
145.1
144.0
3
145.0
149.4
137.3
138.2
4
139.4
125.3
141.6
95.8
5
141.6
138.9
152.2
125.8
Mean of testers
148.4
118.6
151.0
Lines
G.M
138.58
L.S.D
13.63
As shown in Table (10) positive and negative heterosis values were estimated as the percentage of F1'S deviation from mid parental values for the 33
Chapter Four
Results and Discussion
character plant height. Maximum positive heterosis value was 16.85 % recorded by the hybrid 4x7 indicating the over dominance- gene effect followed by the hybrid 3x7 with 16.35%, while maximum negative heterosis value was -5.04 % recorded by the hybrid 3x8 and followed by the hybrid 1x8 with -4.01 %, negative heterosis value confirm the partial dominance- gene effect due the parent with low value. Positive and negative heterosis values results agree with ( Iqbal et. al., 2010 ) Table 10. Percentage values of heterosis for the hybrids of maize for plant height (cm). Heterosis Testers 6
7
8
1
6.2
7.3
-4.0
2
2.2
12.9
-1.6
3
1.1
16.3
-5.0
4
14.1
16.8
14.3
5
3.2
13.6
9.8
Lines
S.E= 1.93 Table (11) showed genetic analysis for the character plant height. The line parent 1, 4 and tester 7 recorded negative values of GCA with -1.731, -6.664 and 2.733 respectively, indicating the contribution of these parents in reducing plant height in their hybrids, maximum positive GCA effect values was 4.558 recorded by line parent 2 and followed by tester 6, line parents 5 and 3 with 2.327, 2.080and 1.758 respectively, confirming the high contribution of these parents in increasing plant height in their hybrids. Concerning to the SCA effect values for hybrids, the hybrid 4x7 with -7.42 gave maximum negative SCA effect value and the hybrid 3x7 with 8.22 gave maximum positive SCA value, followed by the hybrid 5x8 with 34
Chapter Four
Results and Discussion
7.56. The results were in agreement with (Mohammad, 2005; Malik et. al., 2004 and Kara, 2001). The same table showed that ratio of σ2g.c.a/σ2s.c.a was less than unity 0.24 indicating the high contribution of non additive- gene effect as controlled the inheritance of this character, while the average degree of dominance value was more than unity 2.03, heritability in broad sense was 0.36 while in narrow sense it was 0.12 these results confirm the suitability of hybridization to improve this character. Similar results were recorded previously by (El- Shenawy et. al., 2009) Appendix (4) showed the proportional contribution of the interaction of line x tester was higher than lines and testers in to the total variance. Table 11. Estimation of general and specific combining abilities effects, and some genetic parameters for plant height (cm). S.C.A Testers 6
7
8
G.C.A for lines
1
6.92
-2.56
-4.36
-1.731
2
-2.37
4.36
-1.98
4.558
3
-1.24
8.22
-6.98
1.758
4
1.65
-7.42
5.77
-6.664
5
-4.96
-2.60
7.56
2.080
G.C.A For testers
2.327
-2.733
0.407
Lines
S.E
Lines
Testers
Hybrids
2.763
2.140
4.785
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
0.24
27.04
2.03
2.03
0.36
0. 12
35
Chapter Four
Results and Discussion
4.4. Ear height (cm) Data represented in table (12) and appendix (1) confirms the presence of highly significant differences among genotypes for the character ear height. Concerning the parental values ear height restricted between (58.1 to 97.4) cm for the line parent 4 and tester parent 8 respectively, these differences between parental values resulted in presence of significant differences between their hybrids. The hybrid 2x6 produced maximum value due to ear height with 98.9 cm, and followed by the hybrid 5x8 with 97.4 cm, while minimum value was 81.2 cm recorded by the hybrid 4x7. These results were agreement with previous worker (Mohammad, 2005 and Malik et. al., 2004). Table 12. The average values of ear height (cm) for parents and their hybrids. Testers 6
7
8
Mean of lines
1
93.6
88.1
89.7
83.2
2
98.9
87.1
84.0
88.3
3
91.7
91.9
89.3
81.9
4
82.3
81.2
82.9
58.1
5
91.4
89.1
97.4
75.8
Mean of testers
91.4
89.1
97.4
Lines
G.M
86.0
L.S.D
3.927
Table (13) Indicate the presence of significant positive heterosis for ear height as a percentage mean deviation of F1 from mid parental values. All hybrids showed positive heterosis values with the exception of the hybrid 2x8 which 36
Chapter Four
Results and Discussion
recorded negative value with -7.2%. The maximum positive heterosis value was recorded by the hybrid 4x7 with 28.9%, while the minimum positive heterosis value was recorded by the hybrid 1x8 with 1.8%. Similar results were observed previously (Mustafa, 2008; Malik et. al., 2004 and Al- Falahy, 2002). Table 13. Percentage values of heterosis for the hybrids of maize for ear height (cm). Heterosis Testers 6
7
8
1
7.2
16.6
1.8
2
10.0
11.5
-7.2
3
5.8
22.6
2.1
4
10.0
28.9
9.8
5
9.5
23.9
15.5
Lines
S.E= 2.40 The presence of highly significant differences between genotypes for the character ear height confirms the necessity of genetic analysis. As shown in table (14). Line Parent 5 and tester parent 6 showed the highest GCA effect values with 4.113 and 3.049 respectively, while the line parents 4 and tester parent 7 exhibited maximum negative GCA values with -6.378 and -3.178 respectively. Concerning the SCA effected values for the hybrids, the hybrids 2x6 and 5x8 produced maximum positive values with 5.84 and 4.66 respectively, the hybrid 2x8 with 6.11 recorded maximum negative SCA value, followed by the hybrids 5x6 and 3x7 with -4.29 and -3.00 respectively. Some genetic parameters also represented in table (14) due to the character ear height, the ratio σ2g.c.a/σ2s.c.a was less than unity 0.79, and average degree of dominance was more than unity 1.12, indicating 37
Chapter Four
Results and Discussion
the high contribution of non additive- gene effect in controlling the inheritance of this character. Heritability in broad sense was 0.87 and in narrow sense it was 0.53. These results confirmed the suitability of selection method to improve this character. Similar results were reported by (Pshdary, 2011 and Malik et a.,l 2004). According to appendix (4) the lines were contributed by high ratio of ear height character and reached 44.98%. While testers and lines x testers were contributed (22.45%) and (32.45%) respectively for inheritance of this character. Table 14. Estimation of general and specific combining abilities effects, and some genetic parameters for ear height. S.C.A Testers 6
7
8
G.C.A for lines
1
0.07
0.83
-0.91
1.913
2
5.84
0.27
-6.11
1.480
3
1.27
-3.00
1.73
-1.120
4
-2.89
2.27
0.63
-6.378
5
-4.29
-0.37
4.66
4.113
G.C.A For testers
3.049
-3.178
0.129
Lines
S.E
Lines
Testers
Hybrids
0.796
0.616
1.378
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
0.79
24.90
15.70
1.12
87.7
53.7
4.5. No. of ears/plant The mean values of the character No. of ears/plant were represent in Table (15), confirming highly significant differences among genotypes Appendix (1). 38
Chapter Four
Results and Discussion
Regarding the parental values, the line parent 3 gave maximum No. of ears/plant with 1.73, and followed by the line parent 5 with 1.60, while the line parent 4 showed the lowest No. of ears/ plant with 1.00 ears. These differences between parental values reflected significantly on their hybrids. The hybrid 3x8 with 1.80 showed maximum No. of ears/ plant, followed by the hybrid 4x7 with 1.76, the hybrid 4x6 with 1.10 recorded the lowest number., these results are in agreement with previous studies (Sundararajan and Kumar, 2011; Flint-Garcia et al., 2009; Mustafa, 2008 and Barakat and Ibrahim, 2006). Table 15. The average values of No. of ears/ plant for parents and their hybrids. Testers 6
7
8
Mean of lines
1
1.2
1.3
1.2
1.1
2
1.2
1.2
1.4
1.2
3
1.6
1.6
1.8
1.7
4
1.1
1.7
1.5
1.0
5
1.6
1.3
1.6
1.6
Mean of testers
1.4
1.5
1.5
Lines
G.M
1.43
L.S.D
0.403
The differences between parental values and their hybrids resulted in producing positive and negative heterosis which was estimated as a percentage deviation from mid-parental values for No. of ears/plant table (16). The maximum positive heterosis values were 37.5 % recorded by hybrid 4x7, followed by the hybrid 4x8 with 20.00%, indicating the over dominance- gene effect for the parent 39
Chapter Four
Results and Discussion
with high value. Maximum negative heterosis values recorded by the hybrid 5x7 with -17.7% and followed by hybrid 4x6 with -9.9% these negative values indicated to the partial dominance- gene effect of the parent. Positive and negative heterosis values previously were reported by (Pshdary, 2011 and Mustafa, 2008). Table 16. Percentage values of heterosis for the hybrids of maize for No. of ears/ plant. Heterosis Testers 6
7
8
1
-6.2
1.4
-8.3
2
-3.8
-6.6
5.9
3
3.1
1.2
11.8
4
-9.9
37.5
20.0
5
5.9
-17.7
3.2
Lines
S.E= 3.46 The genetic analysis of the character No. of ears/plant was represented in Table (17). Maximum positive effect values were recorded by the line parent 3 with 0.249, while the line parent 1 produced maximum negative GCA value with -0.196, concerning SCA effect values of hybrids maximum positive value was 0.29 recorded by the hybrid 4x7, followed by the hybrid 5x6 with 0.17, while the hybrid 4x6 with -0.26 recorded maximum negative SCA value, followed by 5x7 with 0.24. Some genetic parameters were also represented in the same table, the ratio σ2g.c.a/σ2s.c.a was less than unity 0.80, while the average degree of dominance value was more than unity 1.12, signifying the importance of non additive- gene 40
Chapter Four
Results and Discussion
effect which control the inheritance of this character, heritability in broad sense was 0.41, while in narrow sense was 0.25, these results indicated the suitability of hybridization method to improve this character. Other studies showed the same results (Al- Azawy, 2002 and Al- falahy, 2002). The Appendix (4) showed the highest contribution of the line with 50.78% followed by the contribution of line x tester with 39.77% and the interaction of tester had lower role of 9.40% Inheritance of this character. Table 17. Estimation of general and specific combining abilities effects, their variances for No. of ears/plant. S.C.A Testers 6
7
8
G.C.A for lines
1
0.04
0.09
-0.12
-0.196
2
0.04
-0.08
0.04
-0.129
3
0.02
-0.06
0.03
0.249
4
-0.26
0.29
-0.02
0.004
5
0.17
-0.24
0.08
0.071
G.C.A For testers
-0.091
0.022
0.069
Lines
S.E
Lines
Testers
Hybrids
0.077
0.062
0.141
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
0.80
0.026
0.016
1.12
0.41
0.25
41
Chapter Four
Results and Discussion
4.6. Ear length (cm) Highly significant differences were founded between genotypes for the character ear length in Appendix (1) and table (18), maximum ear length was recorded by tester parent 8 with 21.4 cm and followed by the line parent 2 with 17.9 cm. while the parent 3 gave minimum ear length 12.1cm. Regarding to the hybrids, the hybrid 2x7 with 21.9cm recorded maximum ear length, followed by the hybrid 2x8 with 21.8 cm, while the hybrids 4x6 with 15.8 gave the lowest value of ear length. Table 18. The average values of ear length (cm) for parents and their hybrids. Testers 6
7
8
Mean of lines
1
18.4
18.0
18.5
16.4
2
17.1
21.9
21.8
17.9
3
16.6
18.5
17.2
12.1
4
15.8
17.7
17.3
12.3
5
17.3
20.2
17.5
14.4
Mean of testers
15.3
15.8
21.4
Lines
G.M
17.3
L.S.D
2.906
Table (19) showed heterosis as a percentage mean deviation of F1's hybrid for mid- parental values of ear length, the hybrids 1x8 and 5x8 produced negative heterosis with(-2.1 and -2.21)% respectively. Maximum heterosis value was 33.7% recorded by the hybrid 5x7 and followed 33.0% for the hybrid 3x7, while the hybrid 3x8 gave the lowest positive heterosis value with 2.9%, the negative value signify the partial gene effect for the parent, while the positive values ratify the 42
Chapter Four
Results and Discussion
over dominance gene effect for the parent with high value. Positive and negative heterosis values previously were reported by (Mostafavi et. al. (2008) and Mohammad, 2005). Table 19. Percentage values of heterosis for the hybrids of maize for ear length (cm). Heterosis Testers 6
7
8
1
16.4
11.8
-2.1
2
3.0
30.3
11.2
3
21.1
33.0
2.9
4
14.4
26.4
3.5
5
16.8
33.7
-2.2
Lines
S.E= 3.17 Highly significant mean squares for genotypes due to ear length, confirmed the genetic analysis for this characters in (table 20 and Appendix 1), line parent 2 gave maximum GCA effect value with 2.027 and followed by tester parent 7 with 1.022, confirming the increase in ear length values in the hybrids of these two parents. Maximum negative GCA value was -1.340 recorded by line 4, followed by tester parent 6 with -1.231, regarding the SCA effect values for the hybrid the hybrid 2x8 gave maximum positive value 1.35and followed by the hybrid 1x6 with 1.30, while the hybrid 2x6 showed maximum negative SCA effect value with -1.98, and followed by the hybrid 1x7 with -1.29 some genetic parameters were presented in same table for this character. The variance component due to GCA was larger than SCA in which resulted in producing the ratio σ2g.c.a/σ2s.c.a became more than unity confirming the high contribution of additive gene effect in the inheritance of 43
Chapter Four
Results and Discussion
this character the average degree of dominance was less than unity 0.60, while heritability in broad sense was 0.47 and in narrow sense it was 0.40, confirming that the hybridization method is suitable to improve this character. Similar results were recorded by (Mohammad, 2005; Desai and Singh, 2001; Sadalla et al., 2012; Sharief et al., 2009 and Hallauer, 1997). The Appendix (4) showed the high contribution of the line with 44.18% followed by the contribution of tester with 29.40% and the interaction of line x tester had lower role 26.42% for inheritance of this character. Table 20. Estimation of general and specific combining abilities effects, their variances for ear length. S.C.A Testers 6
7
8
G.C.A for lines
1
0.30
-1.29
-0.01
0.049
2
-1.98
0.63
1.35
2.027
3
0.40
0.01
-0.41
-0.784
4
0.09
-0. 20
0.11
-1.340
5
0.20
0.84
-1.04
0.049
G.C.A For testers
-1.231
1.022
0.209
Lines
S.E
Lines
Testers
Hybrids
0.586
0.454
1.015
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
2.27
2.38
0.43
.060
0.47
44
h2.n.s 0.40
Chapter Four
Results and Discussion
4.7. No. of rows/ear Table (21) showed the average of No. of rows/ ear for genotypes, in which there were highly significant differences among them Appendix (1), tester parent 8 produced maximum value for No. of rows/ ear with17.3 rows, followed by line parent 3 with 14.2 rows, while line parent 4 showed minimum No. of rows/ ear with 10.6 rows, these differences between parental values affected hight significantly in their hybrids. The hybrid 1x6 with 17.3 rows gave maximum No. of rows/ ear, and followed by the hybrids 4x8 and 3x8 with 16.6 and 16.2 respectively, while the hybrid 4x7 with 12.2 rows gave minimum values. Table 21. The average values of No. of rows/ear for parents and their hybris. Lines 6
7
8
Mean of lines
1
17.3
13.5
13.8
13.5
2
13.3
13.5
15.1
13.5
3
15.3
15.1
16.2
14.2
4
12.9
12.2
16.6
10.6
5
14
14.6
15.5
12.6
Mean of testers
13.9
14.0
17.3
Testers
G.M
14.1
L.S.D
1.51
Highly significant differences between parental values and their hybrids resulted in different positive and negative heterosis for this character Table (22). Maximum positive heterosis value was 26.2 % recorded by the hybrid 1x6 and followed by the hybrid 4x8 with 19.4%, while the hybrid 1x8 gave maximum negative heterosis value -10.3%. Positive and negative heterosis values previously 45
Chapter Four
Results and Discussion
were reported by (Chen, 2010; Hallauer et. al., 2010; Hochholdinger and Hoecker, 2007, Al- Zawy, 2002 and Al-Falahy, 2002). Table 22. percentage values of heterosis for the hybrids of maize for No. of rows per ear. Heterosis Testers 6
7
8
1
26.2
-1.4
-10.3
2
-2.9
-1.4
-1.9
3
9.2
10.2
3.1
4
5.7
Zero
19.4
5
6.0
9.7
4.0
Lines
S.E= 2.36 Highly significant mean squares due to genotypes confirmed the necessity of genetic analysis for this character as shows in Table (23). Regarding the GCA effect values for parents, line parent 3 showed maximum positive effect value 1.178, followed by the tester parent 8 with 1.111, while the parent 1 produced maximum negative GCA effect value -0.710, followed by the tester parents 6 and 7 with -0.555 and -0.556 respectively. Concerning to the SCA effect values for the hybrids, the hybrid 4x8 showed maximum positive effect value 1.59, while the hybrid 4x7 showed maximum negative SCA effect value -1.18. Some genetic parameter represented in same table where the variance component due to GCA was larger than SCA, making the ratio σ2g.c.a/σ2s.c.a became more than unity 1.45, while the average degree of dominance value was less than unity 0.82, indicating to the importance of additive- gene effect in controlling the inheritance of this character, heritability in broad sense was 0.68, while in narrow sense it was 0.50, 46
Chapter Four
Results and Discussion
confirming the importance of selection method to improve this character. These results were in agreement with the results of the previous researchers such as (Om et. al., 2006; Sumathi et. al., 2005 and Chaudhary and Chaoudhary. 2002) The Appendix (4) showed the high contribution of the tester with 41.37 %, followed by the contribution of line with 31.37 % and the interaction between of line x tester had lower role 26.89% in the inheritance of this character. Table 23. Estimation of general and specific combining abilities effects, their variances for No. of rows/ear. S.C.A Testers 6
7
8
G.C.A for lines
1
0.44
0.44
-0.89
-0.710
2
-0.18
0.15
0.04
-0.415
3
0.33
0.11
-0.44
1.178
4
-0.41
-1.18
1.59
-0.416
5
-0.18
0.48
-0.30
0.363
G.C.AFor testers
-0.555
-0.556
1.111
Lines
S.E σ2g.c.a/σ2s.c.a 1.45
Lines
Testers
Hybrids
o.309
0.240
1.178
σ2A
σ2D
ā
h2.b.s
h2.n.s
1.37
0.47
0.82
0.68
0.50
47
Chapter Four
Results and Discussion
4.8. No. of grains/ row Data on average values of No. of grains/row for genotypes represented in Table (24) confirmed highly significant differences among them Appendix (1). Regarding to parental values the tester parent 8 gave maximum number of grains/ row, followed by the line parent 2 with 35.3 and 32.6 respectively, while the line parent 4 produced minimum No. of grains/ row with 22.1 grains. Concerning to the hybrid values, the hybrid 2x7 showed maximum value with 35.9 grains, followed by the hybrids 4x7, 2x6, 5x6 and 3x6 with 35.8, 35.7, 35.6 and 35.5 respectively, while the hybrid 5x8 gave minimum No. of grains/ row with 27.5 grains. Table 24. The average values of No. of grains/row of parents and their hybrids. Testers 6
7
8
Mean of lines
1
30.0
28.7
31.5
29.2
2
35.7
35.9
35.0
32.6
3
35.5
29.7
30.9
25.9
4
30.0
35.8
32.3
22.1
5
35.6
33.2
27.5
22.9
Mean of testers
28.8
26.8
35.3
Lines
G.M
30.9
L.S.D
4.37
These differences between parental values and their hybrids produced different positive and negative value heterosis, where values estimated as the percentage of F1's deviation from mid- parental values, The hybrids 1x8 and 5x8 produced negative values (-2.1 and -5.4) % respectively, while the hybrid 4x7 with 46.7% recorded maximum positive heterosis value, followed by the hybrids 5x7 48
Chapter Four
Results and Discussion
and 3x6 with (33.8 and 30.0) % respectively. Positive and negative heterosis values were previously were reported by (Pshdary, 2011; Liu and Tollenaar, 2009; Mustafa, 2008; Hochholdinger and Hoecker, 2007; Birchler et. al., 2003; Soengas et. al., 2003; Al-Falahy, 2002). Table 25. Percentage values of heterosis for the hybrids of maize for No. of grains/row: Heterosis Testers 6
7
8
1
3.4
2.5
-2.1
2
16.2
20.8
3.2
3
30.0
12.9
0.9
4
18.1
46.7
12.5
5
21.5
33.8
-5.4
Lines
S.E= 3.78 Highly significant mean squares due to genotypes confirmed genetic analysis as represented in Table (26). Line parent 2 gave maximum positive GCA effect value 3.044, indicating the good ability of this parent for increasing this character in its hybrids, line Parent 1 gave the highest negative GCA effect value -2.433. Concerning the SCA effect values of the hybrids, maximum positive effect was 2.88, followed by 2.60 and 2.55 for the hybrids 4x7, 5x6, and 3x6 respectively, where as the hybrid 5x8 recorded maximum negative SCA effect value with -3.52, followed by the hybrid 4x6 with -3.43. As shown in same table the variance component due to SCA was larger than GCA, making the ratio σ2g.c.a/σ2s.c.a be less than unity 0.32 and the average degree of dominance was more than unity 1.74, indicating to the high contribution of non-additive gene effect in controlling the 49
Chapter Four
Results and Discussion
inheritance of this character . Similar results were recorded by (Dubey et. al., 2001and Sinsawat et. al., 2004; Konak et. al. 2001) .Heritability in broad sense was 0.56, while in narrow sense it was 0.22, these results confirmed the importance of hybridization method to improve this character. Similar results were recorded previously by (Bocanski et. al., 2009 and Mostafavi 2008). Appendix (4) showed the proportional contribution of the interaction of line x tester was higher than lines and testers in this character, appeared to be its about 52.62%. Table 26. Estimation of general and specific combining abilities effects, their variances for No. of grains/row. S.C.A testers 6
7
8
G.C.A for lines
1
-0.95
-1.51
2.46
-2.433
2
-0.76
0.22
0.55
3.044
3
2.55
-2.51
-0.04
-0.467
4
-3.43
2.88
0.55
0.278
5
2.60
0.92
-3.52
-0.422
G.C.A for testers
0.909
0.162
-1.071
lines
S.E σ2g.c.a/σ2s.c.a 0.32
Lines
Testers
Hybrids
0.890
0.689
1.541
σ2A
σ2D
ā
h2.b.s
h2.n.s
3.65
5.54
1.74
0.56
0.22
50
Chapter Four
Results and Discussion
4.9. (300) Grain weight (g) Table (27) and Appendix (1) showed that there were highly significant differences between genotypes for the character (300) g grain weight. Regarding the parental values, line parent 1 produced maximum weight of (300) grain weight which was 101.3 g, followed by the tester parent 8 with 100.7 g, while the lowest weight was 81.6 g recorded by tester parent 6. The differences between parental values affected high significantly on their hybrid values, the hybrid 2x8 with 110.6 g recorded maximum value , followed by the hybrids 1x7 and 2x7 with (108.2 and 107.7)g respectively, while the hybrids 4x6 and 3x7 each with 87.4and 87.4 g recorded minimum values for (300) grain weight. Table 27. The average values of (300) grain weight for parents and their hybrids. Testers 6
7
8
Mean of lines
1
105.1
108.2
102.0
101.3
2
101.7
107.7
110.6
90.7
3
87.9
87.4
87.5
82.3
4
87.4
90.2
94.6
87.8
5
105.3
99.0
99.0
95.9
Mean of testers
81.6
94.2
100.7
Lines
G.M
96.0
L.S.D
2.41
The differences between parental values and their hybrids resulted in positive and negative heterosis values for the hybrids (Table 28). The hybrid 5x6 gave maximum heterosis value with 18.7% , followed by hybrids 2x6 and 2x7 with (18.1 and 16.5) % respectively. Maximum negative heterosis value was -4.37% recorded 51
Chapter Four
Results and Discussion
by hybrid 3x8. Positive and negative heterosis values were previously reported by (Pshdary 2011; Mohammad 2001and Al- Janaby 2003). Table 28. Percentage values of heterosis for the hybrids of maize for (300) grain weight Heterosis Testers 6
7
8
1
14.9
10.7
0.9
2
18.1
16.5
15.5
3
7.2
-0.9
-4.37
4
3.1
-0.8
0.4
5
18.7
4.2
0.7
Lines
S.E= 2.06 Highly significant mean squares due to genotypes signified the necessity of genetic analysis due to the character (300) grain weight (Table 29). Regarding the GCA effect values for parents, maximum positive values was 8.410 recorded by the line parent 2, followed by the line parent 1 with 6.877, while the line parent 3 produced maximum negative GCA effect value -10.658, followed by line parent 4 with -7.482. The estimation of SCA effect values for the hybrids as presented in the same table confirmed that hybrid 5x6 gave maximum value 4. 96 followed by the hybrids 2x8 and 4x8 with 3.42 and 3.40 respectively. Maximum negative SCA values effect was -4.17 rerecorded by the hybrid 2x6. Some genetic parameter for this characters were also represented in same table indicating that the variation component due to GCA was larger than SCA where produced the ratio σ2g.c.a/σ2s.c.a became more than unity 2.80 similar result were founded by (Kara, 52
Chapter Four
Results and Discussion
2001and Mustafa et. al., 2008).While the average degree of dominance was less than unity 0.58. Ratify the importance of additive gene effect in controlling the inheritance of (300) grain weight, heritability in broad sense was 0.97 and in narrow sense was 0.83. These results confirmed the importance of selection method during the early generation to improve this character, similar result were founded by (Rafiq et. al., 2010; Mohammad, 2005 and Sujiprihati et .al. 2003). The Appendix (4) showed the highly contribution of the line with 88.73% followed by the contribution of the interaction line x tester with 10.85% and the tester had very low role of 0.42% to for inheritance this character. Table 29. Estimation of general and specific combining abilities effects, their variances for (300) grain weight. S.C.A Testers 6
7
8
G.C.A for lines
1
0.77
2.82
-3.59
6.877
2
-4.17
0.75
3.42
8.410
3
1.03
-0.43
-0.61
-10.658
4
-2.59
-0.81
3.40
-7.482
5
4.96
-2.34
-2.62
2.852
G.C.AFor testers
-0.740
0.255
0.485
Lines
S.E σ2g.c.a/σ2s.c.a 2.80
Lines
Testers
Hybrids
0.495
0.383
0.857
σ2A
σ2D
ā
h2.b.s
h2.n.s
73.96
12.83
0.58
0.97
0.83
53
Chapter Four
Results and Discussion
4.10. Grain yield (t/h) Highly significant differences were observed between genotypes for the character grain yield (table 30) and Appendix (1). Maximum grain yield value recorded by the tester parent 8 with 5.1 t/ h and followed by the line parent 5 with 3.2 t/ h, minimum grain yield value was, 1.2 recorded by the line parent 4. These differences between parental values for this character resulted in highly significant differences among their hybrids. The hybrid 4x7 with 5.9 t/h recorded maximum value, followed by hybrids 1x6, 2x6, 2x7, and 2x8 with (5.9, 5.7, 5.7 and 5.6) t/ha respectively, the hybrid 4x6 with 2.0 t/ha recorded the lowest yield. Table 30. The average values of grain yield t/h for parents and their hybrids. Testers 6
7
8
Mean of lines
1
5.9
5.3
4.1
3.1
2
5.7
5.7
5.6
2.4
3
3.3
4.6
3.2
1.3
4
2.0
5.9
4.1
1.2
5
4.1
4.2
3.7
3.2
Mean of testers
2.8
3.2
5.1
Lines
G.M
3.96
L.S.D
0.158
The differences between parental values and their hybrids resulted in heterosis with different values were shown in Table (31), all hybrids showed positive heterosis values with the exception of the hybrid 5x8 witch recorded negative heterosis values -11.9% the hybrid 4x7 produced maximum positive heterosis value 167.7% and followed by the hybrid 2x6 with 114.2% , while the hybrid 1x8 gave the lowest positive heterosis value with 0.7% .The high positive 54
Chapter Four
Results and Discussion
values for heterosis confirm the over dominance gene effect for the parent with high value, while the heterosis with negative value indicated to the partial dominance for the parent with low value Positive and negative heterosis values were previously reported by (Mustafa, 2008 and El- Diasty, 2007). Table 31. Percentage values of heterosis for the hybrids of maize for grain yield t/h. Heterosis Testers 6
7
8
1
71.8
68.1
0.7
2
114.2
100.0
4.2
3
58.2
102.6
0.9
4
0.98
167.7
31.0
5
36.7
32.0
-11.9
Lines
S.E= 13.45 Highly significant mean squares due to genotypes for this character confirm the necessity of genetic analysis as represent in Table (32). Regarding the GCA values for the parents, the line parent 2 with 1.151 showed maximum positive GCA effect value, followed by the tester parent 7 with 0.650, while the line parent 3 showed maximum negative GCA value -0.783.Concerning to the SCA effect values for the hybrids, maximum positive effect value was 1.25 recorded by the hybrid 4x7, followed by the hybrid 1x6 with 1.06, while the hybrid 4x6 recorded maximum negative SCA effect value with -1.70. Similar results were founded by (El-Moselhy 2005; Bocanski et. al., 2009 and Mostafavi 2008). Some genetic parameters for this character were also represented in the same table, where the variance component due to SCA was larger than GCA, making the 55
Chapter Four
Results and Discussion
ratio σ2g.c.a/σ2s.c.a became less than unity 0.54, while the average degree of dominance was more than unity 1.35 confirming the high contribution of non additive- gene effect with the respect of additive-gene effect in controlling the inheritance of grain yield character, heritability in board sense was 0.99, while in narrow sense was 0.51. These results confirmed the suitability of hybridization method in improve this characters. These results were in agreement with these (ElDiasty, 2007; El-Moselhy, 2005 and Atta, 2001) Appendix (4) showed the high contribution of the line with 44.04%, followed by the contribution of line x tester with 39.22% and the contribution of tester had lower role 16.72% for inheritance this character. Table 32. Estimation of general and specific combining abilities effects, their variances for grain yield t/h. S.C.A Testers 6
7
8
G.C.A for lines
1
1.06
-0.43
-0.63
0.610
2
0.33
-0.65
0.32
1.151
3
-0.11
0.25
-0.13
-0.783
4
-1.70
1.25
0.45
-0.480
5
0.43
-0.42
-0.01
-0.498
G.C.A For testers
-0.308
0.650
-0.343
Lines
S.E
Lines
Testers
Hybrids
0.037
0.029
0.064
σ2g.c.a/σ2s.c.a
σ2A
σ2D
ā
h2.b.s
h2.n.s
0.54
0.01
0.93
1.35
0.99
0.51
56
Chapter Four
Results and Discussion
57
REVIEW OF LITERATURE 2.1. Line × Tester Analysis An understanding of the genetic architecture of parent, their mode of inheritance will greatly aid the breeder to device appropriate breeding methodology to incorporate the characters in question .Line × Tester analysis is one of the methods employed by which the genetic architecture of given character, the combing ability and heterosis could be understood (Sundararajan and Kumar 2011). The mating design (line x tester) suggested by (Kempthorne, 1957) has been extensively used to estimate (g.c.a) and (s.c.a) variances and their effects , also it is used in evaluation of nature of gene action involved in the expression of economically important quantitative characters (Shawarf and Baker, 1981). One of the methods used to select the parental material for hybridization from the germplasm to identify their genetic worth is Line x Tester analysis. This mating design provides information about the general and specific combining ability of parents and estimates of other genetic parameters (Comstock and Robinson, 1948 and Singh and Chaudhary, 1985). Breeders need more information on selecting testers to indentify lines for formation of synthetics and need more user-friendly methods to study general combining ability and specific combing ability of genotypes (Narro et. al., 2003) Using abroad based genotype as a tester, the general combining ability of line is tested in the top cross method in which several testers are used (Kempthorne, 1957). The litter design thus provides information about general and specific combing ability of parent and at same time it is helpful in estimating various types of gene effects (Singh and Chaudhary, 1985). 3
Chapter Two
Review of Literature
In formulating programs for genetic improvement of yield, a breeder faces the difficult task of choosing parents for hybridization. This is because yield is a complex character, composing several component, each of which is polygenetically controlled and therefore, very susceptible to environmental fluctuations (Singh and Joshi. 1966). The breeder used the program (line × tester) analysis, with some modification in the partition of variety effect. One of question of genetic experimentation is the choice of crossing system. This determines what kinds in genetic information can be obtained in a given experiment. Among the crossing system that have been used most often are (line × tester) crosses (Singh and Chaudhary .1979). Rawlings and Thompson (1962) used Line × tester analysis to estimate GCA and SCA of inbred parent. Since the development of new cultivars through hybridization is a continuous process, information on combining ability of new cultivars remains important. The ultimate goal of various breeding methods in maize is the production of improved genotypes. Hence short cut but efficient methods are needed for isolation and identification of superior genotypes which can be used in hybrid breeding programs (Arshad et. al., 2003). For selection of inbred lines tolerant to inbreeding depression and being superior in genetic potential, early generation testing is desirable (Barata and Carena, 2006). Breeding for disease resistant varieties and availing high yielding seeds of both true and top cross hybrids to small scale farmers remains as the only feasible option to boost maize productivity. In order to achieve this, potentially suitable parents and superior combinations must be identified. Line x tester is useful in deciding the relative ability of female and male lines to produce desirable hybrid combinations. It also provides information on genetic components and enables the 4
Chapter Two
Review of Literature
breeder to choose appropriate breeding methods for hybrid variety or cultivar development programmers. Information on combining ability effects helps the breeder in choosing the parents with high general combining ability and hybrids with high specific combining ability (Dillen, 1975). The (line × tester) scheme involves crossing one parental line with each of tester. The crossing yields its progenies, i.e. it is full of subfamilies. In the second scheme, different sets of parents (male and females) are used. In crosses of type, well-known standard varieties are most frequency used as tester (it is assumed that line may represent various levels of homozygosity). The (line × tester) system permits the estimation of effects of general combining ability (g.c.a) of line and tester and also the specific combining ability (s.c.a) of pairs of parental genotypes. There are many univariate statistical methods for the proper genetic analysis of data form (line × tester) experiments (Singh and Chaudhary ,1979 and Kaczmarek and Tuczkiewice 1986). Baracat and Ibrahim (2006), used line x tester analysis to estimate heterrosis and combining ability to many characters for maize, the analysis of variance showed highly significant between lines, testers and their crosses, while, lines × testers interaction were significant for grain yield, resistance to late wilt disease under two location and their combined, while, it was significant for combined of days to 50% silking. The overall diversity and total variation in the experimental material was obvious from the results of tester and line × tester interaction. In most cases the crosses from the same genetic background exhibited relatively low levels of heterosis, but high levels of heterosis from crosses of related lines were also observed (Flint-Garcia et. al., 2009).
5
Chapter Two
Review of Literature
Sundararajan and Kumar (2011), used line x tester analysis to estimate combining ability to many characters of maize, observed significant differences among hybrids for all the characters studied, plant height, days to 50 % tasseling, days to 50% silking, ear length, number of grains per ear, 100 grain weight and others. The interaction effect of Line × Tester was significant for all characters. Ali et. al., (2012) observed varying degree of combining ability and the contribution of line × tester interaction was relatively higher for plant height Compared to the other characters.
2.2. Combining ability Combining ability describes the breeding value of parental lines to produce hybrids. The concept of combining ability is becoming increasingly important in plant breeding. It is especially useful in connection with testing procedures, in which it is desired to study and compare the performances of line in hybrid combination (Griffing, 1956 and Basal and Tugut, 2003). Combining Ability is divided into two types: 1- General combining ability 2- Specific combining ability The terms general and specific combining abilities were originally defined by (Sprague and Tatum, 1942). They defined the terms as follows: general combining ability is used to designate the average performance of a line in hybrid combination, while the term 'specific combining ability' is used to designate those cases in which certain combinations do relatively better or worse than would be expected on the basis of the average performance of the lines involved. Combining ability studies provide information on the genetic mechanisms controlling the inheritance of quantitative characters and enable the breeders to 6
Chapter Two
Review of Literature
select suitable parents for further improvement or use in hybrid breeding for commercial purposes (Ali et. al., 2012). Combining ability analysis is useful to assess the potential inbred lines and also helps in identifying the nature of gene action involved in various quantitative characters. This information is helpful to plant breeders for formulating hybrid breeding programmer (Alam et. al., 2008). Uddin et. al., (2006) reported significant differences for general combining ability and specific combining ability indicated the presences of additive gene effect as well as non additive gene effects for controlling the characters. However, relative magnitude of this variance indicated that additive gene effects were more prominent for all characters studies except grain yield/plant. The effects of general Combining Abilities (GCA) and Specific Combining Abilities (SCA) are important indicators of potential value for inbred lines in hybrid combinations. Differences in GCA effects have been attributed to additive gene, the interaction of additive x additive, and the higher-order interactions of additive genetic effects in the base population, while differences in SCA effects have been attributed to non-additive genetic variance (Falconer, 1981). Lesser the gap between tasseling to silking in a cross, greater will be the probability of grain setting hence, more will be grain yield while maximum grain yield is the prime objective in most breeding programs. In order to develop high yielding early maturing hybrids, information regarding GCA and SCA inheritance pattern can facilitate breeders in improving genetic architecture of the maize in particular direction in the long run. Many researchers reported that genetic variance among testcross progenies using inbred testers was about twice, when broad base testers were used (Sharief et. al., 2009).
7
Chapter Two
Review of Literature
The importance of estimating combining abilities is that, the predominant component of genetic variation determines the choice of an efficient breeding method for incorporation of concerned genes into new materials (Dhabholkar et. al., 1989). In terms of genetic variances, GCA represents additive gene action and additive × additive type of epistatic interaction. SCA is made up of non-additive types of variances, comprising mainly dominance and epistasis (Griffing, 1956). Desai and Singh (2001) reported significant difference in gca and sca effects for the characters., days to 50 % tasseling, days to 50 % silking, anthesis, silking interval, plant height, ear height and number of leaves / plant. Kara, (2001) observed significant gca effects for all the characters and significant sca effects for ear width, ear height and grain yield per unit area. Konak et. al., (2001) obtained non-additive gene effects for ear length and number of grains/rows on ear and additive gene effect for yield, 1000-grain weight, plant height, ear height and days to silking. Mustafa and Sadalla (2008) obtained that the inbred lines in ear length, rows/ear, grains/ row and grain yield character showed the highly positive GCA. The ratio of GCA/SCA was more than one for most characters, and the hybrids showed highly positive SCA for rows/ear, grains/row and yield characters. Also Sadalla et. al., (2012) showed that the most parents gave high value of SCA for plant height, No. ears/plant, No. rows/ear, ear length, and 100 kernel weights. The hybrids gave the higher SCA for yield and ear/plant. The ratio of σ2 GCA/ σ2SCA was more than one for plant ear height, ear length and yield.
8
Chapter Two
Review of Literature
2.3 Heterosis Heterosis is defined as an increase in performance of hybrid over their parental lines, most noticeably in characters like vigor, fertility, resistance, yield, quality, and many others. Application of crop heterosis plays an important role in increase of grain yield (Wang et. al., 2007). The term "heterosis" was formed almost one century ago by (Shull, 1908) to facilitate the description of this phenomenon and as short form for the phrase "stimulation of heterozygosis" (Thiemann et. al., 2009). Two methods were proposed to actually measure the performance of a hybrid relative to its parents: 1- Mid-parent (MP) hetrosis: It is the performance of hybrid relative to the average performance of its parents expressed in percentage. 2- High- parent (HP) heterosis: It is performance of hybrid relative to the performance of its best parent expressed in percentage. The HP heterosis method has been less used but it provides better and more accurate formation (Hallauer et al., 2010). Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. The phenomenon has apparently been recognized in one form or another for centuries by various civilizations (Chen, 2010). Generally heterosis can be divided into two broad categories, true heterosis and pseudo heterosis. In case of true heterosis, there is an increase in general vigor, yield and adaptation. In case of pseudo heterosis, the F1 hybrid exhibits increase in vegetative growth only. It refers to the superiority of F1 over the standard
9
Chapter Two
Review of Literature
commercial check variety. So, it is also called economic heterosis or superiority over checks (Sharief et. al., 2009). Heterosis, or hybrid vigor, refers to the superior performance of an F1 hybrid relative to its homozygous inbred parents with regard to various biological phenotypes, including agronomic characters like yield and its components. In maize (Zea mays L.), heterosis has been extensively exploited, but the underlying molecular and genetic bases remain largely deciphered, as they do in other plants (Birchler et. al., 2003; Soengas et. al., 2003, Hochholdinger and Hoecker, 2007; Liu and Tollenaar, 2009). Recently it has been divulged that the utilization of heterosis is extremely effective for the genetic improvement of different characters and that the concepts of combining ability are the fundamental tools for enhancing Productivity of different crops in the form of F1 hybrids (Flint-Garcia et. al., 2009). Identification of combination with strong yield heterosis is the most important step in developing crop hybrids. Generally, parents with a higher general combining ability and long genetic distance can produce a hybrid with better yield performance (Shahnejat-Busheri et al., 2005). Li-Jizhu et. al., (2004) reported highest heterosis for ear grain weight and lowest for ear row number. All studied characters were controlled by additive gene action. Ear length had significant additive and dominance effects, whereas, row number and ear grain weight had dominant and epistatic effects, respectively. The highest and the lowest values of average heterosis were observed for ear weight in all genotypes. All hybrid combination had positive heterosis, the highest value was 150% above the average of the parents value (Aliu et. al., 2008).
10
Chapter Two
Review of Literature
Semel et. al., (2006) report that better- parent heterosis was observed primarily for reproductive characters related to yield. Ali et. al., (2012) reported significant level of heterosis for reproductive characters. About 73% of the testcrosses showed higher grain and 52% testcrosses showed positive GCA effects; while 48% where having negative SCA effects over all, 48.3% of testcross showed positive SCA, while 51.7% were having negative SCA effects. Estimates of MP and HP heterosis among hybrids for quantitative characters studied were significant for days to tasseling (MP) and grain yield (MP and HP) respectively. However, MP values were larger in magnitude than for HP. Consistent with estimates of inbreeding, negative estimates were recorded for days to flowering and ear placement indicating that the hybrids matured earlier and had lower ear placement than their field corn for parents (Olaoye et. al., 2009). Kara (2001) observed positive heterosis for all studied characters except for days to tasselling with the average hybrid being 79.89% above that of the parent. While Shahwani et. al. (2001) noticed a positive and significant heterosis in 17 hybrids, While 11 hybrids showed heterobeltiosis for ear per plant. Netaji et. al., (2000) obtained significant and positive heterosis and heterobeltiosis for grain and moreover the expression of heterobeltiosis was most evident for grain yield / plot followed by, ear length, plant height and number of grain rows / ear. Geetha (2001) obtained maximum heterosis for grain yield/ plant, ear weight and number of grain/ear, also reported that significant positive heterosis in grain yield was found to be associated with the heterosis for plant height, number of grains/ row, 100- grain weight and number of rows / ear. 11
Chapter Two
Review of Literature
2.4 Gene action Gene action and gene effects have been extensively studied in many crop species. Gene action is important in determining cultivar type (hybrid, pure line, synthetic, etc.), breeding methodology used to develop cultivars, and in the interpretation of quantitative genetic experiments. The study of gene action has been approached of quantitative in which ways (Sprague, 1966). Knowledge of gene action helps in the election of parents for use in the hybridization programmers and also in the choice of appropriate breeding procedure for the genetic improvement of various quantitative characters. Depending upon the genetic variance, Gene action is of three types, additive gene action. Dominance gene action and epistatic gene action, dominance and epistatic gene action jointly are referred to as non-additive gene action. Since genetic variance are used
as measures of gene action, all those factors which affect
estimates of genetic variance also affect gene action (Singh, 2004). The improvement of maize yields for ear weight depends on the knowledge of the type of the gene action involved in its inheritance and also the genetic control of related characters such as the capacity for production (Rezaei, 2004). Result on the inheritance of maize yield and agronomical characters were presented by many researchers, grain/plant and 100- grain weight were found to be under non-additive gene control (Dubey et. al., 2001and Sinawat et. al ., 2004). Additive gene action was responsible for the genetic expression for days to 50% tassling and rows/ ear. Over dominance gene action for grain yield/plant in maize was reported by (Prakash et. al., 2004 and Ali et. al., 2007). Maize breeder has used several biometrical techniques to study the genetic architecture of the quantitative characters including grain yield. The general 12
Chapter Two
Review of Literature
conclusion from these studies that great bulk of genetic revealed variance is additive, followed by dominance whereas epistasis is of little importance (Beck et. al., 1990; Zaffer, 1999 and Kumar et al.2005). Ojo et. al., (2007) reported that hybrid means were significantly higher than parental means for all characters except shelling (%). Additive gene action was more important than non-additive gene action for grain yield. Ali et. al., (2007) reported that additive genetic variance was important for grains/ ear and 1000-grain weight, and non-additive gene action was important for plant height, ear height, days to silking and days to maturity. Recurrent selection procedures may be useful in the sense that it will exploit both additive and non-additive components of genetic variation for bringing about improvement in grain yield and its related attributes. Such a strategy will help increase frequency of favorable alleles while maintaining genetic variation in breeding population (Doerksen et. al., 2003). The study of plant height is in accordance with those of (Prakash and Ganguli, 2004 and Kumar et. al., 2005) who reported over dominance type of gene action for the same characters. However, the finding of (Singh and Roy 2007) revealed additive gene action effect in the inheritance of plant height. Singh and Roy, (2007) observed that plant height and days to maturity were governed by the additive gene effects while grain yield/plant and some other characters were controlled by non-additive gene action. Tabassum and Saleem, (2005) revealed that the expression of leaf area/ plant, 1000-grain weight and grain yield plant-1 was mainly governed by over dominance type of gene action while the importance of additive gene effects was highlighted for plant height. 13
Chapter Two
Review of Literature
Kumar and Gupta,(2003) reported that the additive and dominance components were highly significant for days to tasselling, days to maturity, plant height, and main cob height from ground level, number of cobs per plant and 100kernel weight. Mustafa and Sadalla, (2008) reported that additive gene action was greatest in dominance gene action of all studies characters except ear/plant, and the average degree of dominance more than one for characters ear/plant, ear length and yield. The mode of inheritance of grains number / row was reported to be partial dominance, whereas over-dominance was of greater importance for grain yield, number of kernels /row and 100- grain weight (Srdić et. al., 2007). Sujiprihati et. al., (2003) observed that non-additive gene action played a significant role in the inheritance of plant height, ear height and grain yield and its related characters. The involvement of over dominance in the inheritance of days to 50% tasseling was reported by (Kumar et. al., 2005 and Singh and Roy 2007). Equal role of additive and non-additive gene actions were observed for days to maturity. Additive genetic variance was preponderant for grains/ear and 1000grain weight and non-additive gene action was involved in plant height, ear height, days to silking (Alam et. al., 2008).
2.5 Heritability Heritability can be defined as the percentage quantitative variable of a plant that is due to genetic, the remaining percentage being due to environment (Robinson 2004). Heritability in broad-sense (h2B), is ratio of the total genetic variance to the phenotypic variance. Heritability in narrow-sense (h2N), is the ratio of additive 14
Chapter Two
Review of Literature
genetic variance to the phenotypic variance. The h 2N is so important to plant breeders because the effectiveness of selection depends on additive portion of the genetic variance in relation to the total variance (Falconer and Mackay, 1996). Heritability is a measure of genetic factors influence on phenotypic character. Heritability (h2N) is considered to be height when the result is more than 50%; medium when the result was in the range of 20-50%, and it is low when the result was less than 20% (Al- Auddai and Mahamed, 1999). Days from planting to harvesting had lowest broad sense heritability while ear weight showed highest heritability value (Ojo et. al., 2006). Broad-sense heritability, coefficients of variability and genetic advance values were computed for days taken to tasseling, number of days taken to silking, plant height, ear length, number of kernel rows/ ear, number of kernels/row, 100grain weight and grain yield/ plant. Low, medium and high estimates of broad sense heritability were found in different plant characters under study (Mahmood et al., 2004). Sujiprihati et. al., (2003), founded varied estimates of board sense heritability between locations for all characters, indicating the presence of broadsense of genotype x location interaction effect on the genetic performance on the hybrids. One hundred-grain weight gave the highest broad-sense estimate at both locations, as well as in the combined analysis (80.2%). Narrow- sense heritability estimates obtained from the variance component method were generally in agreement with those from the parent-offspring regression method, although those obtained from the latter were slightly higher for almost all characters. Rafique et. al., (2004) showed that heritability was also higher than 80% for all characters, showing heritable variation among genotypes. 15
Chapter Two
Review of Literature
Higher estimates of plant height (cm), ear height (cm), ear length (cm), grains/row and grain yield/plant indicating to the preponderance of additive gene action (Rafiq et. al., 2010) Grain yield is complex quantitative trait that depends on number of factors. It's uneder great influence of environmental condition, has complex mode of inheritance and low heritability (Bocanski et. al., 2009).
16
A- CONCLUSIONS 1. There were significant differences among genotypes for all characters. 2. Significant positive and negative heterosis values resulted in most characters due to influences of partial and over dominance genes.
3. The general combining ability variance was higher than specific combining ability for the characters days to 50% tasseling, ear length, No. rows/ear and 300g grain weight. This means that characters were under the control of additive- genes.
4. The heritability in narrow sense was high for the characters 300g grain weight, ear length, grain yield and No. rows/ ear. These results suggested selection method for improving these characters.
5. The tester {Sc (890x3007)} showed as good combined for the characters plant and ear height, ear length, No. of grains/ row and grain yield, therefore, this tester can be used in inbreeding program to improve these characters.
6. the inbreed lines 3078, MSI and ZP 434 were superior for the characters grain yield, 300g grain weight, ears/plant and ear length.
7. The tester TALAR had highest value for the characters plant and ear height, ear length, No. of rows/ear, No. of grains/ row and grain yield.
8. The inbred lines had more contribution in the total variance in most characters.
B- RECOMMENDATION 1. Using the tester {Sc (890x3007)} to estimate the GCA for yield and its components. 2. The inbred lines 3078, MSI and ZP 434can be used in hybrid production program. 3. Conducting favorable selection methods for improving these characters to the high narrow sense heritability. 57
Appendices Appendix 1. Mean Squares of variance analysis of genotypes, Line, Testers and their crosses for studied characters. Replication
Genotyp es
Parents
P.vs.C
Crosses
Lines
Testers
L. x T
MSe
2
22
7
1
14
4
2
8
44
Days to % 50 tasseling
10.14
19.57**
18.64 **
131.13**
12.07*
25.63*
3.62n.s
7.42n.s
4.98
Days to % 50 silking
64.62
34.96**
21.40n.s
224.04**
28.23**
Plant height(cm)
909.40
489.31**
1006.74**
1642.85**
148.19*
170.10n.s
Ear height (cm)
5.61
250.79**
437.16**
160.40**
92.63**
No. ears/plant
0.03
0.16**
0.20**
0.05n.s
Ear length(cm)
8.23
19.54**
27.77**
No. rows/ear
0.47
6.60**
No .grains/ row
10.39
(300)g. grains weight Yield grains ton/ha
Source of variance
d. f characters
21.86n.s
26.41*
9.88
97.87*
149.81*
68.70
145.83*
143.58*
52.79**
5.70
0.15**
0.27n.s
0.10n.s
0.11n.s
0.06
102.53**
9.49**
14.68*
19.53*
4.39n.s
3.09
10.27**
6.17*
4.80**
5.33*
13.89**
2.26*
0.86
51.01**
61.47*
331.00*
25.78**
35.24n.s
15.00n.s
23.74**
7.13
10.07
221.00**
173.64**
646.90**
214.27**
665.38*
6.36n.s
40.68**
2.20
0.02
6.09**
4.52**
45.35**
4.07**
6.28*
4.76n.s
2.79n.s
0.01
48.27n.s
F0.05 (1:44) = 4.061 , F0.05 (22:44) = 1.7888 , F0.05 (7:44) = 2.222 , F0.05 (4:44) = 2.583 , F0.05 (8:44) = 2.157 , F0.05 (2:44) = 3.290 F0.01 (1:44) = 7.516 , F0.01 (22:44) = 2.2775 , F0.01 (7:44) = 3.076 , F0.01 (4:44) = 3.778 , F0.01 (8:44) = 2.945 , F0.01 (2:44) = 5.122
68
Appendices Appendix 2. Average Heterosis of hybrids for the character. Hybrids Characters
1x6
2x6
3x6
4x6
5x6
1x7
2x7
3x7
4x7
5x7
1x8
2x8
3x8
4x8
5x8
Days to % 5 tasseling
-4.4
-5.4
-5.4
-7.3
-0.1
0-3
-4.8
-10.2
-4.9
-2.0
-7.1
-1.9
-6.9
-6.5
-4.8
Days to % 50 silking
-3.8
-8.2
-13.3
-6.9
3.1
-7.9
-12.3
-19.7
-4.4
-11
-5.9
5.0
-2.0
-2.4
0.6
Plant height(cm)
6.2
2.2
1.1
14.1
3.2
7.3
12.9
16.3
16.8
13.6
-4.0
-1.6
-5.0
14.3
9.8
Ear height(cm)
7.2
10.0
5.8
10.0
9.5
9.5
16.6
11.5
22.6
28.9
23.9
1.8
-7.2
9.8
15.5
No. ears/plant
-6.2
-3.8
3.1
-9.9
5.9
1.4
-6.6
1.2
37.5
-17
-8.3
5.9
11.8
20.0
3.22
Ear length(cm)
16.4
3.0
21.1
14.4
16.8
11.8
30.3
33.0
26.4
33.7
-2.1
11.2
2.9
3.5
-2.2
No. rows/ear
26.2
-2.9
9.2
5.7
6.0
-1.4
-1.4
10.2
0.0
9.7
-10
-1.9
3.1
19.4
4.0
No .grains/ row
3.4
16.2
30.0
18.1
21.5
2.5
21.8
12.9
46.7
33.8
-2.1
3.2
0.9
12.5
-5.4
(300)g. grains weight
14.9
18.1
7.2
3.1
18.7
10.7
16.5
-0.9
-0.8
4.2
0.9
15.5
-4.3
0.40
0.7
Yield grains ton/ha
71.8
114.2
58.2
0.98
36.7
68.1
100.0
102.6
167.7
32.0
0.7
4.2
0.9
31.0
-11
69
Appendices Appendix 3. Average analysis of the characters Characters
ā
h2.n.s
h2.b.s
σ2g.c.a/σ2s.c.a
σ2 D
Days to % 50 tasseling
0.85
0.27
0.37
1.35
0.81
Days to % 50 silking
1.68
0.20
0.48
0.35
5.51
Plant height(cm)
2.03
0.12
0.36
0.24
27.04
Ear height(cm)
1.12
0.53
0.87
0.79
15.70
No. ears/plant
1.12
0.25
0.41
0.80
0.016
Ear length(cm)
0.60
0.40
0.47
2.76
0.43
No. rows/ear
0.82
0.50
0.68
1.45
0.47
No .grains/ row
1.74
0.22
0.56
0.32
5.54
(300)g. grains weight
0.58
0.83
0.97
2.80
12.83
Yield grains ton/ha
1.35
0.51
0.99
0.54
0.93
70
Appendices Appendix 4. The percentage of the contribution of line and testers and interaction line x ester. characters
Contribution of liner
Contribution of testers
Contribution of LxT
1
Days to 50% tasseling
60.68
4.29
35.03
2
Days to 50% silking
22.12
24.43
54.45
3
Plant height (cm)
32.80
9.44
57.76
4
Ear height (cm)
44.98
22.45
32.56
5
No. of ears/ plant
50.78
9.40
39.77
6
Ear length (cm)
44.18
29.40
26.42
7
No. of rows /ears
31.73
41.37
26.89
8
No. of grains/row
39.06
8.31
52.62
9
(300) grain weight (gm)
88.73
0.42
10.85
10
grain yield (t/ha)
44.05
16.72
39.22
71
Appendices Appendix 5. Metrological data of Sulaimani region for 2012. Wind
85.3
70.5
109.0
0.5
189.7
5.6
7.6
6.6
Feb.
2.2
11.6
6.9
42.0
77.4
59.7
94.6
1.3
165.5
4.8
6.9
5.8
Mar.
4.4
14.1
9.3
35.9
72.9
54.4
175.0
1.3
202.9
4.8
7.1
9.8
Apr.
14.3
25.0
19.6
15.0
38.0
26.0
19.6
1.5
330.0
8.2
11.4
10.4
May
18.8
30.7
24.7
21.0
50.0
35.5
34.8
1.2
249.6
8.2
12.4
10.3
Jun.
24.9
36.9
30.9
15.5
33.8
24.6
0.0
2.0
198.8
8.4
12.7
10.5
Jul.
27.1
39.9
33.5
16.0
36.2
26.1
0.0
1.5
181.0
10.5
15.5
13.0
Aug.
40.6
26.3
33.9
13.6
36.4
20.0
0.0
1.1
330.0
9.2
14.0
11.6
Oct.
22.7
36.0
29.3
16.5
39.9
28.2
0.0
0.6
30.0
9.0
12.5
10.7
Dec.
28.9
17.7
23.3
28.9
57.2
43.0
32.3
0.5
161.9
9.6
12.6
11.1
72
Avg.
56.6
Max.
Direct ion
6.0
Min.
Speed m/s
10.3
Avg.
1.8
Max.
Jan.
Min.
Avg.
Evaporation (mm)
Max.
Precip. (mm)
Humidity % Min.
Months
Temperature C⁰
Appendices Appendix 6. Physical and chemical properties of soil at Qilyasan location. Soil property
Values
Soil Texture
Silty clay
%Sand
5.27
% Silt
43.20
%Clay
51.53
E.C (ds.m -25)
0.2
% Organic matter
1.13
%Total Nitrogen
0.16
Available phosphate(ppm)
5.24
Soluble Cations and Anions Meq/L Calcium (Ca2+)
1.1
Magnesium (Mg2+)
0.6
Potassium(K+)
0.143
Sodium (Na+)
0.108
Carbonate (CO3=)
0.00
Bicarbonate (HCO3=)
1.5
Chloride (CL-)
1.1
73
