The effects of three genes which modify leaves and stipules in the pea plant

Summary The effects of three genes (af, st and tl) which modify leaf and stipule form and size in peas were investigated in families generated by crossing eight near-isogenic lines in all combinations but excluding the reciprocals. The eight parents and their equivalent phenotypes differed significantly for all characters due to the direct effects of all three genes, with their combined effects being especially influential in some instances. The effects of the recessive allele at any one of the three loci in homozygotes was to reduce plant productivity with stst having the most pronounced effect. The response of characters tended to be similar in direction, if not in magnitude, to any of the three genes. Partial dominance was frequently associated with the tl locus, and was especially obvious in afaf Tltl genotypes.