抄録
The amount of chlorophyll-deficient and other detrimental recessive mutants concealed in a cultivated buckwheat population was estimated for 17 populations from different parts of the world, by conducting more than 3000 sib crosses. The following types of abnormalities were found in cotyledons; albino 0.2%, yellow 3.4%, pale yellow 5.2%, pale green 7.5%, variegated 1.0%, morphological 3.5% and others 2.0% on the average. The frequency of each type did not vary so much among the populations and it coincided well with the frequency previously observed in the Japanese populations. Each type was also found in the foliage leaves at about 2/3 of the frequencies in cotyledons. No case of polymorphism of chlorophyll-deficient or other detrimental mutants has been found so far. These data confirmed the conclusions given by Ohnishi (1982); most of the detrimental mutants appear to be maintained in a population at very low frequency by mutation-selection balance; cases of balanced polymorphism are extremely rare, if they exist at all, in cultivated buckwheat populations.
