水稻磷效率相关性状的遗传特性

利用数量遗传模型对P1、P2、F1、F2．3等4个世代的相对分蘖率、有效穗、生物产量及经济产量等性状进行了遗传分析。混合遗传模型分析表明：低磷胁迫条件下，相对分蘖率和相对有效穗两个指标适合两对主基因的加性．显性．上位性的模型，两对主基因之间存在着广泛的加性、显性和上位性效应，也存在多基因修饰；相对分蘖率和相对有效穗的最大效应主基因以加性效应为主，次大主基因以显性效应为主，而相对生物量与相对经济产量两个指标符合两对加性．显性．上位性主基因＋多基因的模型，主基因遗传力分别达到60．08％和37．70％，多基因遗传力分别达到32．15％和58．9％。表明相对分蘖率、有效穗和生物量的主基因遗传力均较高，可以作为水稻耐低磷遗传育种的指标。而相对经济产量的主基因遗传力相对较低，说明经济产量受气候等环境因素影响较大。

Genetic Analysis of Agricultural Traits in Rice Related to Phosphorus Efficiency

Relative tillering ability, available spike, biomass, and grain yield of P1, P2, F1, and F2. 3 were used to study the genetic development of rice related to phosphorus efficiency with a quantitative genetic model. The results indicated that under a low-P condition, the relative tillering ability and the relative available spike were apt to the additivity-dominance-epistasis model with two couples of major genes, between which additive, dominant and epistatic effects existed, and with multi-gene modifications. Their maximum major gene effect mostly indicated additivity, but sub-maximum major gene effect mostly indicated dominance. Relative biomass and grain yield were apt to the additivity-dominance-epistasis and multi-genes model. The heritabilities of the major genes were 60.08% and 37.70%, and those of the multi-genes were 32.15% and 58.9%, respectively. This meant that the heritabilities of the relative tillering ability, the relative available spike, and the relative biomass were high, so they were ideal indexes for rice breeding tolerating to low-P stress; whereas, the heritability of the relative grain yield was low, which meant that the grain yield was easily affected by the environment.