Low levels of 16-kDa globulin, the main allergen in rice grain. All mutant lines had floury endosperm. Low 16-kDa polypeptide content is controlled by a single recessive gene. Attempts to separate genes for low 16-kDa polypeptide content and floury endosperm by crossing with the original cultivar were unsuccessful, suggesting the tight linkage of these two genes or pleiotropism of a single mutated gene, flo(t).