Genic Analysis of Anthocyanin Pigmentation in Rice Plant

Abstract

In order to analyze the genic systems for coloration of various organs and other characters in rice, gene marker strains were crossed with Taichung No. 65, a representative ”Japonica” variety of Taiwan, and other strains, and segregation for apiculus and stigma colorations were investigated. Particular attention was paid to its linkage relations to the anthocyanic pigmentation of various other organs. The anthocyanic coloration of apiculus is found to be controlled by three complementary genes C, A, and P. Their combinations in the used strains were determined based on F_2 segregation ratios. The coloration of stigma is usually hypostatic to that of apiculus. Genes Ps_1 anJ Ps_2 which spread the pigment produced by C, A, and P into stigmas were assumed first. It was assumed further that there were two complementary inhibitors I_1^(Ps) and I_2^(Ps) which suppress the action of Ps, and that the later is linked with A. Genes for colorations in other parts of the plant, i.e. glumes, leaf sheath, node and internode, which were generally hypostatic to apiculus coloration were also surveyed. It was confirmed that red pericarp was controlled by Rc and Rd genes which act in a complementary fashion. Two genes Pp and Pb are concerned with purple pericarp which is hypostatic to C and A and differs from those for red pericarp; Pp is epistatic to Pb, and Pp was found to be closely linked with A, one of apiculus-coloration genes, with a recombination fraction of 5.1~9.4%. The purple coloration of leaf blade is controlled by a modifier Pl which distributes anthocyanic pigment produced by C^B and A. It is completely linked with or synonimous with Pb. Linkages were found between lg (ligulessness) and Rp (modifier for hull coloration), lg and d_9 (dwarf), Pl (purple leaf blade) and Ps_1, (stigma color), Ps_1, and Ph (phenol reaction), Rp and Ps_1, and Pb and Rp genes.