Genetics of seed impermeability in soya bean

SummarySix parental cultivars (Bragg, Bragg-black seed, Kalitur, Ankur, WT-125 and Glycine formosana), 15 F1's, eight F2's and eight F3's (Bragg × WT-125, Bragg × Glycine formosana, Bragg-black seed × WT 125, Bragg-black seed × Glycine formosana, Kalitur × WT-125, Kalitur × Glycine formosana, Ankur × WT-125 and Ankur × Glycine formosana) were evaluated for seed impermeability. WT-125 and Glycine formosana were identified as impermeable types (92·18, 77·46% impermeability, respectively). The other four varieties, namely Bragg (2·93% impermeable seeds), Bragg-black seed (11·7% impermeable seeds), Kalitur (no impermeable seeds) and Ankur (0·94% impermeable seeds) had soft seed or normal seed.The segregation pattern for impermeability in the F2 and F3 generations of eight crosses showed the involvement of a pair of dominant genes in Bragg × Glycine formosana, Bragg-black seed × WT-125, and Bragg-black seed × Glycine formosana, three pairs of dominant genes in Bragg × WT-125, Ankur × WT-125 and Ankur × Glycine formosana, and four pairs of dominant genes in Kalitur × WT-125 and Kalitur × Glycine formosana for seed impermeability, assuming maternal control as hard seed was a seed-coat phenomenon.Vr, Wr graphical analysis also indicated that WT-125 and Glycine formosana possessed mostly the dominant genes for seed impermeability, while the remaining four cultivars contained mostly the recessive genes. The correlation coefficient of Yr (parental mean) and Vr + Wr was negative and high (— 0·907) confirming that most of the dominant genes in the parental cultivars were acting towards high seed impermeability. Thus the overall results obtained through diallel analysis of 15 F1's were in agreement with those obtained through Mendelian analysis.