Analysis on Genetic Effect of Cadmium and Arsenic Contents in Rice Grains

The genetic effect of the contents of heavy metal elements cadmium(Cd) and arsenic(As) in rice grains was studied with 4 rice male sterile lines and 6 rice restorer lines through the incomplete diallele cross design. The results showed that there existed significant difference among different genotypes in the contents of Cd and As in brown rice. For the Cd content, its general combining ability(gca) effect and specific combining ability(sca) effect of both male sterile lines and restorer lines were very significant, indicating that the genetic improvement of parents and the selection of F1 hybrids are both very important in developing hybrids with low Cd content in grains. For the As content, the gca effect of male sterile lines and restorer lines were insignificant, but their sca effect was very significant, indicating that the key is to select F1 hybrids in developing hybrids with low As content in grains. Furthermore, it was found that the genetic improvement of male sterile lines had a much greater effect than the genetic improvement of restorer lines and the selection of F1 hybrids had in breeding hybrids with a low rate of Cd absorption.