BREEDING FOR SOME QUANTITATIVE TRAITS IN COMMON WHEAT

Abstract

The aim of this investigation was to determine the heterosis and ty es of

gene action and their interaction with seasons (Environments) for some drowth I and yield characteristics, i.e. heading date, plant height, the height up to flag

leaf, height of flag region, flag leaf area, number of tillers per plant, nu ber of I spikes per plant, number of spikelets per spike, number of kernels per 'spike, 1000-kernel weight, grain yield per plant, biological and straw yields. To achieve this target F1 and F2 of half diallel cross among five parental lines nd/or varieties namely representing wide range of variability in most of the dtudied traits were utilized. I I In 1991/92 season, crossing was made with all possible combi ations I among selected plants and evaluated in the successive season 1992/93 in a I randomized complete block design with three replicates. In 1993/94 seasc;m, two

experiments were conducted, the first involved the parental lines ad ten ' possible F1 crosses, and the second included parents and F2 crosses. Each experiment was laid out in a randomized complete block design witthree replications. / I Data were recorded on ten and 60 individual guarded plants randomly ' sampled from each plot from F1 and F2, respectively. Analysis of varianice was I performed for the studied traits in each season and then a combined a'nalysis

was carried out whenever homogeneity of error variance was realized. HJterosis I mean squares and effects for both generations were calculated. General and specific combining ability estimates were obtained by employing Griffing's! (1956) diallel cross analysis designated as method 2 model 1. The obtained resIts can be summarized as follows.