Inheritance of short-petiole trait in groundnut

Inheritance of the short-petiole character was studied in the F1, F2 and F3 generations resulting from crosses between the short-petioled genotype ICG10145 and the normal-petioled genotypes TMV2, Gangapuri and Kadiri 3. F1 plants from all three crosses had normal petioles indicating the recessive nature of the short-petiole trait. F2 segregation showed a satisfactory fit for 63 normal (N) to 1 short-petioled (S) plants suggesting that three recessive genes governed inheritance of the short-petiole trait. The three recessive gene hypothesis was further confirmed by the segregation in F3 families. In two of the three crosses, the ratio of segregating to non-segregating normal F2-derived F3 families showed a good fit to the expected 37 true breeding to 26 segregating families. In all three crosses, the segregating families showed a good fit to the expected ratio of 4 families with 63 N:1 S, 16 with 15 N:1 S, and 3 with 3 N:1 S segregation. The proposed gene symbols for the short-petiole trait are sp1 sp1 sp2 sp2 sp3 sp3.