Inheritance of three seed-coat color genes in Vigna sinensis Savi

The segregation of three gene pairs governing seed-coat color and pattern in Vigna sinensis Savi is described:

B, the black gene, is completely dominant to b, brown.

W, the Watson pattern gene, causes the color to be finely stippled over the seed coat.

H, the Holstein, an incompletely dominant pattern gene, restricts the color to about half the seed coat.

With both W and H, the beans are self-colored; with both w and h, the color is restricted to a small area about the hilum.

A breeding program of Blackeye 5 × Iron showed interaction among these three gene pairs to produce ten phenotypes. No evidence of linkage was found. Studies of all possible genotypes in the F₃ generation provided data that fitted expectation very closely in genotypes segregating for one or two genes and in relatively small families. However, in large populations of genotypes segregating for three genes, significant deviations from expectation were found. Re-examination of the data to test the hypothesis of unequal efficiency between gametes containing dominant and recessive alleles indicated a slightly greater efficiency of gametes containing dominant alleles.