Analysis for Yield amoung wheat Varietie

Combining Ability Analysis for Yield and Yield Related Traitsamong Wheat Varieties and their F1 Hybrids : 

Combining Ability Analysis for Yield and Yield Related Traitsamong Wheat Varieties and their F1 Hybrids Dr. Shahzadi Mahpara, Assistant Porfessor, PBG, Sub-Campus, UAF, at Depalpur

Slide 2: 

For any breeding programme aiming at hybridization, knowledge of better combiner parents is a prerequisite. It is important to achieve genetic gain within limited resources and minimum time. Among various genetic techniques, combining ability analysis developed by Griffing (1956) is perquisite for important information for selection of parents in terms of the performance of their hybrids. Introduction

Slide 3: 

Yield is a polygenic trait and is greatly influenced by the environmental changes. Any improvement in yield and its related characteristics: plant height, flag leaf area, spike length, number of spikelets per spike, number of grains per spike and spike density through selection and breeding would help to improve unit area production.

Materials and Method : 

Materials and Method The research work presented was carried out in the experimental area of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. Under field conditions, soil pH was 6.5, EC 4 dS m-1 and photoperiod for wheat was 10 h in November, 2004. The experimental material used in the present studies consisted of seven wheat varieties/lines; Shahkar-95, Parwaz-94, Iqbal-2000, Uqab-2000, MH-97, 4072 and Punjab-96.

Slide 5: 

Seeds of these seven varieties were sown in the field and before maturity their crosses were made in all possible combinations. At maturity, F0 seeds from all the crosses were collected. During next crop season, seven wheat varieties/lines (parents) and their hybrids (F1) were planted in the field following a triplicated randomized complete block design. Thirty plants of each genotype were grown in a 5 m long row in each replication.

Slide 6: 

Ten guarded plants were selected randomly from each row for the following traits viz., plant height, Flag leaf area Number of tillers per plant Peduncle length Spike length 1000-grains weight Grains yield per plant.

Results and Discussion : 

Results and Discussion This study evaluated the genetic variability among seven wheat varieties/lines and their F1 hybrids, selected on the basis of maturity period and high yield characters. These genotypes and their F1 hybrids showed variability in their genetic architecture. All genotypes differed significantly (P ~ 0.0 1) for traits like plant height, flag leaf area, number of tillers per plant, peduncle length, extrusion length, spike length, number of spikelets per spike, spike density, number of grains per spike, 1000-grains weight and grain yield per plant (Table I). Significant differences among genotypes for grain yield and related traits in different sets of material of wheat have been reported (Menon & Sharma, 1997; Ambreen et al., 2002).

Results and Discussion : 

Results and Discussion Assessment of variability Analysis of diallel cross data using combining ability approach (Griffing, 1956) showed that total variation among the genotypes was partitioned into variation due to general and specific combining ability and reciprocal effects. Mean squares for GCA, SCA and reciprocal effects were highly significant (P ~ 0.01) for all the traits under study. Thus, additive type of gene action was more prominent for the said traits but non-additive genetic effect was important in case of plant height and grain yield per plant

Estimates of variation components of general(σ2g), specific (σ2s) combining ability, reciprocal effects(σ2r), error (σ2e) and GCA/SCA ratios in a 7X7 diallelcross of wheat : 

Estimates of variation components of general(σ2g), specific (σ2s) combining ability, reciprocal effects(σ2r), error (σ2e) and GCA/SCA ratios in a 7X7 diallelcross of wheat Traits σ2g σ2s σ2r σ2e GCA/SCA Plant height (cm) 2.80 4.04 2.02 3.14 0.69 Flag leaf area (cm2) 2.93 0.68 0.82 0.75 4.13 No. of tillers per plant 0.15 -0.09 0.08 0.28 -11.11 Peducle length (cm) 1.54 0.47 0.70 0.79 3.27 Spike length (cm) 0.14 -0.02 0.05 0.24 -7.0 1000-grains weight (g) 1.31 0.49 0.29 2.08 2.67 Grain yield per plant (g) 0.57 -5.26 1.21 1.03 -0.11

Conclusion : 

Conclusion Parent like Punjab-96 proved as a best general combiner for flag leaf area, peduncle length, spike length and 1000-grains weight. Uqab-2000 was also found as best general combiner for number of flag leaf area and1000-grains weight MH-97 for number of tillers per plant and grain yield per plant. These three parents can be used in hybridization program for obtaining desirable combinations.

References : 

References Griffing, B. 1956. Concepts of general and specific combining ability in relation to diallel crossing system. Aust. J. Biol. Sci. 9: 463-493. Menon, U. and S.N. Sharma, 1997. Genetics of yield determining factors in spring wheat over environments. Indian J. Genet., 57: 301–6 Phoelman, J.M. and D.A. Sleper, 1997. Breeding Field Crops. 4th edition, pp: 259–61. Iowa State University Press. Ambreen, A., M.A. Chowdhry, I. Khaliq and R. Ahmad, 2002. Genetic determination for some drought related leaf traits in bread wheat. Asian J. Plant Sci., 1: 232–4. Steel, R.G.D., J.H. Torrie and D.A. Discky, 1996. Principles and Procedures of Statistics: A Biometrical Approach, 3rd edition. McGraw Hill Book Co., New York