A 6X 6 diallel cross analysis was conducted to determine mean degree of dominance, distribution of recessive and dominant alleles and the ratio of dorinant to recessive alleles in parental population for eight quantitative characters in 3oybean.
Parents and F1progenies obtained by crossing between varieties,were compared in a randomized complete block design. Significant differences were observed among treatments in all traits. Method of regression analysis suggested by Hayman(1954) was used to study graphical analysis. It was determined that degree of dominance for plant heihgt, no. of pods per plant, no. of seeds per plant, seed yield per plant and protein percentage is over dominance, However, for no. of seeds per pod and oil percentage, partial dominance and for 100 - seed weight complete dominance was observed. Plant height , no. of pods per plant, no. of seeds per plant, no. of seeds per pod, 100-seed weight, seed yield and protein percentage were controlled by dominant alleles, however, oil percentage was controlled by recessive alleles.
Ratios of dominant to recessive alleles obtained for oil percentage and no. of pods per plant were 2.285 and 1.16, respectively. However, non-allelic interactions were not observed in parents for any trait.
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