Correlation Analysis between Grain Color and Cyanidin-3-glucoside Content of Rice Grain in Segregate Population

This study examined the genetic variation of cyanidin 3-glucoside (C3G) contents in blackish-purple rice. F2 populations were established from crosses between blackish purple rice and normal white rice. The blackish rice cultivars used were Jilinheimi, Heidao38, LK1A-2-12-1-1, Heugjinju, and No2, and the common white rice cultivars used were Hwachung super giant embryo and Heugbal. The purple pericarp color is known to be controlled by a set of dominant alleles, Pb(Prp-b) and Pp(Prp-a). In this study, the segregation of the black purple:brown:white pericarp in the F2 population was 9:3:4, demonstrating that the purple pericarp color was controlled by two dominant complementary genes. The F2 distribution of C3G showed continuous variation, with a tendency toward a lower level in all the crosses. However, some F2 crosses, such as Jilinheimi/Heidao38 and Jilinheimi/LK1A-2-12-1-1, showed transgressive segregation of the C3G content. C3G content of Jilinheimi linked on 84% level in C3G content of F2 population between Jilinheimi/Heidao38, and 41.3% level in Jilinheimi/LK1A-2-12-1-1. The results of the color difference meter and C3G content analysed by HPLC revealed highly significant correlations between the seed coat color of the colored rice germplasm and that of the segregated populations. There was a significant positive correlation between the C3G content with L* (lightness) and b* (yellowness). The a* (redness) was different in each cross, but there was a significant positive correlation between the C3G content with L* and b*.