关键词: 杂交水稻, 籼稻, 品质, 相对优势, 优势指数

Abstract: Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines and their 63 F 1 hybrids were chosen to compare 11 characters of grain quality between F₁ hybrids and their parents in indica hybrid rice. Based on the test results of relative heterosis of all characters in all hybrids, the frequency of negative dominance and heterosis was much higher than that of positive dominance and heterosis, indicating that the values of F₁ hybrids were lower than the means of their parents in quality characters as a whole. There existed apparent disparity in grain quality performance among F₁ hybrids which varied with characters. The characters of chalky area percentage, chalky rice percentage, gel consistency and head rice had a great variation in all kinds of tested heterosis indices including mid parent heterosis index, heterosis index over high value parent, and heterosis index over low value parent, which suggest that special attention should be paid to selection of F 1 hybrids in these characters in breeding. The mean values of F 1 hybrids were significantly lower than those of their higher parents in all characters at 0.05 or 0.01 levels; close to or significantly (P=0.01) lower than those of their mid parent values in all characters except for milled rice length and amylose content; and significantly (P=0.05 or 0.01) higher than those of their lower parents in all characters except for brown rice, milled rice and gel consistency.

Key words: hybrid rice, indica, grain quality, relative heterosis, heterosis index