HETEROSIS, GENERAL AND SPECIFIC COMBINING ABILITY ESTIMATES AT F, And F2 GENERATIONS Of A 8 X 8 DIALLEL CROSS POPULATION OF BARLEY

Abstract

This study was carried out over three growing seasons (from 1997 to 2000) under Bornova-Izmir ecological conditions. Eight parents (Schooner, Prisma, Nomad, Alexis, Ariel. Vulga, Kaya and Quantum-109)-diallel crosses without reciprocals were made in the 1997-98 growing season. Eight parents and 28 F, crosses obtained were grown at single progeny rows with three replications in the 1998-99 growing season. In 1999-2000 growing season, the parents and F2's were grown in two reps in which the planting was done by machine in a plot consisting of six rows, 5 m long and 20 cm apart. Days to heading (days), plant height (cm), thousand kernel weight (g) and grain yield/plot (g) were measured and the protein content (%) was determined in both F1, and F2 generations. The preliminary analyses of variance indicated that significant differences among genotypes were present for all the traits at F2, but except the heading date and protein content at F1, generation. Analysis of variance for general and specific combining abilities (GCA and SCA) at F1, and F2 generation showed that GCA and SCA were significant for all traits at F2. GCA were significant for grain yield. plant height and thousand kernel weight whereas SCA was only significant for plant height at F1, generation. Highly significant positive correlations between GCA and SCA variances obtained from F1, and F2, indicated that the F2 generation could effectively be used for assessing the GCA and SCA. Kaya and Schoorer were found to be good general combiners for the protein content. Schoorer x Vulga (11 % and 10 %), Prisma x Alexis (10 % and 11 %), Alexis x Ariel (10% and 12 %), Alexis x Vulga (9 % and 11 %) and Ariel x Vulga (10% and 12 %) having always relatively low protein contents at F1, and F2, were considered as desirable crosses for beer industry. Kaya x Prisma (16 %), Schoorer x Alexis (15 %) and Prisma x Ariel (15%) having high protein content at F2 generation could be recommended for animal feeding.