籼型杂交水稻杂种与亲本的稻米品质比较

Comparison of Grain Quality Between F_1 Hybrids and Their Parents in Indica Hybrid Rice

以具广泛代表性的 7个不育系和 9个恢复系及其配制的 6 3个组合为材料 ,对籼型杂交水稻 11个稻米品质性状的杂种与亲本的表现进行了比较研究。就全部杂交组合各品质性状相对优势而言 ,无论是超亲优势、完全显性还是部分显性 ,都表现为负向的几率远大于正向。组合间杂种品质表现的差异因性状而异 ,无论是中亲优势指数、超高亲优势指数 ,还是超低亲优势指数 ,均以垩白大小、垩白粒率、胶稠度和整精米率等性状组合间变异为大。全部性状杂种平均值都显著或极显著低于高亲值。除精米长和直链淀粉含量杂种值极显著高于中亲值外 ,其余性状都与中亲值接近或极显著低于中亲值。除糙米率、精米率和胶稠度杂种值低于低亲值外 ,其余性状都显著或极显著高于低亲值。

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 F 1 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 F 1 hybrids were lower than the means of their parents in quality characters as a whole. There existed apparent disparity in grain quality performance among F 1 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.