Fundamental studies one rice breeding through hybridization between Japanese and foreign varieties. VI.

Abstract

Using twenty cultivated rice varieties and their hybrids, relation between genotype and relative contents of anthocyanin pigments found in apiculus of glumes was investigated by means of paper chromatogra phy. The pigments causing purple or red coloration in the site of apiculus proved to be mainly chrysant-hemin and keracyanin. There were, however, traced two faint spots in the chromatographs which were supposed to show the existence of cyanin and uliginosin from their R_f values. In the plants whose genotype was either C^BA, C^BA^d, C^BpA, C^BpA^d, C^B₁A or C^B₁A^d chrysanthemin and keracyanin were always found in almost equal quantity. In the plants of the genotypes C^BrA and C^B₂A, however, keracyanin was remarkably decreased and it was sometimes indetectable. The two alleles, A and A^d proved to control the quantity of pigments as a whole, but not their relative quantity. An inhibitor or a modifier whose gene symbol is l_p and which changes blackish purple due to C^BA to reddish purple, proved to decrease the content of keracyanin. Such a condition is quite analogous to that when C^B is replaced by C^Br or C^B₂ in the absence of l_p. It has been concluded from the facts abovedescribed that the effect of the two genes, C^Br and C^B₂, are substantially different from that of the other allels forming the C-series.