Abstract
Purple rice is a phenotype accumulates anthocyanins in seed coat. To understand genetic background of purple rice, molecular genetic analyses were perfumed using a purple rice, Toyamakuro75, contains thee genomic introgressions from a purple rice, Koketsumochi, to Koshihikari background. The transctiptome analysis revealed expression of a LDOX gene and a bHLH gene located on the introgressed region of chromosome 4, in addition of some genes coding enzymes related to early steps of phenylpropanoid synthesis pathway, increased significantly in pericarp/testa of purple rice. In contrast, the red rice NIL of Koshihikari, NIL(Rd/Rc), shows high expression of not LDOX but LAR. The genotyping of 23 accessions of purple rice using two SNPs sets between Nipponbare and Kasalath, and between Nipponbare and KhauMacKho showed the purple rice accessions are diverse genetic background, i.e. toropical Japonica, temperate japonica and indica, but the region of including the bHLH gene in chromosome 4 is a common derived from tropical japonica. The strong introgression suggested that the purple rice mutation occurred in ancient tropical japonica and selected artificially during rice domestication.
