Chlorophyll-deficient and several morphological genes concealed in Japanese natural populations of wild radish, Raphanus sativus var. hortensis f. raphanistroides.

The amount of chlorophyll-deficient and morphological abnormality genes concealed in natural populations of wild radish, Raphanus sativus var. hortensis f. raphanistroides, was estimated by conducting self-fertilization by means of bud pollination. The frequencies of three mutant genes, green hypocotyl(g), green silique(gs) and hairy silique(hy), were also estimated from the frequency of the self-pollinated lines that segregated mutant homozygotes in the S1 progeny. The frequency of chlorophyll-deficient mutant alleles is within the range expected from the mutation-selection balance theory of population genetics. However, the frequencies of g, gs and hy are higher, on the average 20.5%, 3.6% and 10.6%, respectively, than the frequencies expected from mutation-selection balance. The frequencies did not show any systematic geographical change, nor are they correlated to any particular environmental factors. Hence, the mechanisms that maintain these mutant alleles remain unknown.