不同遗传体系基因效应对水稻籽粒碳氮代谢的影响

选用6个不同类型的水稻品种(系),按完全双列杂交设计(6×5)配成一套亲本、F1和F23个世代的遗传材料。采用包括种子、细胞质、母体植株三套遗传体系的种子性状遗传模型和统计分析方法,分析了稻米可溶性糖含量、全氮含量、糖氮比3个性状的遗传特点。遗传方差分析结果表明,可溶性糖含量和全氮含量两性状的表现同时受到种子、细胞质、母体植株三套遗传体系的控制,其中可溶性糖含量和主要受制于二倍体母体植株核基因的显性效应;全氮含量、糖氮比主要受制于种子核基因的显性效应。遗传率和选择响应分析结果表明,可溶性糖含量、糖氮比的遗传率较小,对其进行选择不易奏效;全氮含量以直接狭义遗传率为主,采用单粒选择易取得较好效果。

Influence of Gene Effects in Different Genetic Systems on Metabolism of Carbohydrate and Nitrogen in Rice (Oryza sativa L.)

Analysis on seed, cytoplasmic and maternal genetic effects for soluble sugar content (SSC), total nitrogen content (TNC), ratio of sugar to nitrogen (RSN) was conducted by using genetic models for quantitative traits of seed in cereal crops. According to complete diallel cross design, parents, F1 and F2 genetic generations derived from six different types of rice varieties (parental lines), were used for this experiment. The main results were as follow. Analysis on genetic variance showed that all the traits were controlled by genes of seed, cytoplasm and maternal plant simultaneously. SSC was mainly affected by dominant effects of diploid maternal nuclear genes, while TNC and RSN by dominant effects of seed nuclear genes. The results of heritabilities analysis indicated that heritabilities for SSC and RSN were small or depressive, implying that selection for them might be invalid. Direct heritability for TNC appeared to be large, for which single seed descent method might be better in genetic selection.