Inheritance of some seed-coat colors and patterns in lima beans

Abstract

FIVE GENE PAIRS governing seed-coat color in lima beans and their relationships to some hypocotyl and flower-color genes are described. These genes are: Cc—governs red vs. white seed-coat color; acts as a basic color factor in the production of colored hypocotyls, flowers, and other seed-coat colors. Rr—produces dark-red seed-coat color and red hypocotyl color in the presence of C_. Pp—produces purple seed-coat, purple hypocotyl, and purple flower color in the presence of C_. C_R_P_—produces black seed-coat, red-purple hypocotyl, and purple flower color. Ss—SS changes red, dark-red, purple, or black seed-coat color to red/buff, dark-red/buff, purple/buff, or black/buff, respectively. The heterozygote, Ss, produces a diffuse-type mottling, which can be distinguished from SS (restricted mottling) or ss (no mottling). Srsr—modifies the background color associated with the mottle allele S; Sr_produces buff background color and srsr red background color. This gene pair is expressed only in the presence of SS or Ss. In mottled genotypes, the effect of the R and P alleles is largely confined to the mottled portions of the seed coat. However, individuals with black mottling generally have slightly darker background colors than individuals with red, dark-red, or purple mottles. Variability among individuals in all of the color groups studied indicates the existence of some seed-coat color genes less effective than the ones described.