COMBINING ABILITY ESTIMATES FOR GRAIN YIELD IN WHEAT

The F1 of spring wheat in a 5×5 complete diallel cross was evaluated for combining ability effects for grain yield and its components under irrigated conditions at Wheat Research Institute, Faisalabad, Pakistan during 2009-10. The mean squares due to genotypes, GCA, SCA and reciprocals were found highly significant except for reciprocal effects of spike length, spikelets per spike and 1000 grain weights which were non-significant. The GCA mean squares were much higher for all traits than SCA and reciprocal variations depicting all traits were under control of additive type of genes except that of number of tillers per plant which was found under control of non-additive genes. Maternal effects were also considerable for all traits except spike length, spikelets per spike and 1000-grain weight. The parents FRET2/KURUKU//FRET2 followed by WBLLII/FRET2//PASTOR and ZARDANA were the best general combiners for grain yield per plant alongwith some other attributes. The crosses ZARDANA x FRET2 / KURUKU // FRET2 followed by SALEEM - 2000 x SSERI / CHIBIA and SALEEM - 2000 x WBLLII / FRET2 // PASTOR proved good specific combiners for grain yield per plant and its some other attributes. The line FRET2 / KURUKU // FRET2 also gave the highest maternal contribution for grain yield per plant, tillers per plant but the cross FRET2 / KURUKU // FRET2 x ZARDANA gave negative maternal contribution for plant height.