A Preliminary Study on the Relationship Between the Indica-Japonica RAPD Differentiation of Parents and Heterosis in Dian Type Hybrid Rice

The relationship between the indica-japonica differentiation of parents and heterosis of hybridin rice was studied with 10 sterile lines, 10 maintainer lines of the sterile lines, 38 restorer lines of Dian typehybrid rice and 40 hybrids derived from the sterile lines and restorer lines. The results indicated that there wasa parabolic correlation between the indica-japonica differentiation of parents detected by RAPD markers andheterosis of hybrid rice. When certain indica-japonica differentiation of parents exists, the percentage of com-binations with positve heterosis and the mean heterosis of hybrids were high. But that didn't mean too muchdifference of parents could lead to stronger hetesosis, that meant overdiffernt parents seldom bring positve het-erotic hybrids. Suitable difference of percent of indica alleles of parents of stronger heterotic hybrid was 12 -16%.