Estimation of Combining Ability and Gene Action for Yield and Its Contributing Traits in Bread Wheat (Triticum aestivum.L)

Combining ability analysis for grain yield and its components, and nature of gene action in bread wheat were investigated using twelve lines (L1 “FLORKA” , L2 “MALLIN” , L3 “KLAK” , L4 “RIZGARY” ,L5 “ARAS” ,L6 “SITEMALL” ,L7 “HIDHAB” ,L8 “ALLAI” ,L9 “OASIS” ,L10 “KAUZ” , L11 “ADANA99” and L12 “ACSAD5”) and three testers (T1 “ABU GHRAIB 3” ,T2 “SHAM 6” and T3 “API 99” ) and  thus 36 crosses produced in line x tester mating design which were evaluated in randomized block design with three replications. Study on gene action revealed the preponderance of non-additive gene action for all traits On the basis of GCA effects, the parents KLAK, ARAS, SITEMALL, ALLAI and tester ABU GHRAIB3 were identified as good general combiners revealing their in desirable direction. Hybrid ABU GHRAIB 3×ALLAI and SHAM6× KAUZ was found to be the best specific cross combination for grain yield and eight traits. However, the best specific cross combinations for other contributing traits were ABU GHRAIB 3× FLORKA for days to 50% heading, ABU GHRAIB 3× FLORKA for plant height in desirable direction for low height of plant and API 99×FLORKA for plant height in desirable direction for height of plant , API 99×ADANA 99 and SHAM6× FLORK for Number of spikelets /spike, SHAM6× KAUZ for leaf area ABU GHRAIB 3 ×ACSAD5 for number of tillers per plant and Number of spikes /plant, ×ABU GHRAIB 3 ALLAI and API 99×ALLAI Number of grains/spike, API 99×ALLAI Biological yield/plant API 99×ALLAI and ABU GHRAIB 3 ×ALLAI for Grain yield/plant, ABU GHRAIB 3 ×ALLAI for harvest index and ABU GHRAIB 3× KLAK for 1000 grain weight.