籼稻米直链淀粉含量的遗传及其基因剂量效应

INHERITANCE AND GENE DOSAGE EFFECTS OF AMYLOSE CONTENT IN INDICA RICE

采用5×5完全双列杂交设计,利用Du-7型分光光度计多组份分析程序,单粒分析了5个直链淀粉含量不同的水稻品种(含1个糯稻)的F_1直链淀粉含量及其基因剂量效应,以及7个正反交F_2,B_1F_1,B_2F_1分离世代直链淀粉含量的遗传。结果表明:正反交F_1直链淀粉含量基本处于双亲之间,直链淀粉含量随基因剂量效应增加而增加。F_1主要表现为第一,第三剂量显著或极显著增加直链淀粉含量。基因剂量效应还明显存在于F_2,B_1F_1,B_2F_1各分离世代,且直链淀粉高含量对低含量或对糯性均表现为单一不完全显性基因遗传,还可能受一些微效基因或修饰因子影响。直链淀粉极低含量对低含量可能受单一不完全显性基因控制,也可能表现为多基因控制的数量遗传。

A 5×5 diallel cross was made between five indica rice varieties (including one waxy variety) which differed in amylose content. The amylose content of single grain was analyzed by the multi-component analysis program of Du-7 spectrophometer. Single grains of parents and F_1's were analyzed to determine the dosage ef- fects of gene responsible for amylose content, and F_2, B_1F_1 and B_2F_1 of seven reciprocal crosses were studied for the inheritance of amylose content. The results are as follows. The mean amylose content of single grain of F_1 was between that of parents in all crosses. The amylose content increased with increase in gene dosage. The first dose and the third dose were able to increase amylose content significantly or very significantly in the F_1 population. The gene dosage effects were also implicated in B_1F_1, B_2F_1 and F_2. High and intermediate amylose content follows the mode of one factor inheritance and partial dominance over waxy or low amylose content, though influence by genes of minor effects or modifiers was also obvious. On the other hand, lower amylose content to low amylose content (i. e., variety Gui63 and Qui6) may be controlled by a single partial dominant gene or polygenes.