【摘要】 笔者考察了光敏不育晚熟粳稻与北方早粳杂交Ｆ_２群体的个体育性频率分布，共考察了可在北京自然长日照条件下抽穗的６个群体。直观方柱图可见均为偏态连续分布，双峰型：过渡型：单峰型＝３：１：２．只有半数群体呈双峰分布型，而且它们的峰（或谷）值所在区间自交结实率小于１０％（尤其是自交完全不结实）个体的频率亦不相同。当然，在其它分布类型的群体间这类个体的频率也不相同，而且数值更小。利用Ｋｒｕｓｋａｌ－Ｗａｌｌｉｓ法，成对比较这些群体，尤其是自交结实率在０－４０％区间的子群体，检验结果表明，来源于同母异父组合的群体分布是不同的。即使同为双峰或单峰型，其间也有显著的差异。考察Ｆ_３世代株系群的结果证明，单峰分布型的群体象双峰型群体一样，分离出不育基因纯合体。据Ｆ_３世代不育株系的数目可推测，这类Ｆ_２个体约有４％。它们并不都集中在低值区间；有不少存在于自交结实率大于４０％的中、高值区间。另一方面，双峰分布型群体中的低值个体只有约５０％形成Ｆ_３不育株系。笔者推测，Ｆ_２世代表现型值除取决于不育主基因型和环境条件外，还受亲本育性基因组成及状态的深刻影响。更多还原

【Abstract】 The frequency distributions of individual plant fertility in 6 F2 populations,which derived from the crosses between PGMS late-maturing japonica varieties and northern early-maturing ones and could head sprouting under natural long day condition in Beijing;were investigated.The visual bargraphs show con tinuously abnormal distribution with distinguishing feature.The ratio of bimodal type:middle type:unimodal type is 3: 1: 2. Only half of these populations appear as bimodal distribution, but among them both the location of their peaks or of valleys and the frequency of plants which have seed set rate less than 10%(especially complete self-sterile ones)are different.Among the others,the frequencies of sterile plants also different,and much less than the formers.These distribution patterns were compared pairly with Kruskal-wallis’statistic method.The comparison especially concentrated on the parts of the populations,the seed set rates of which range from 0 to 40%. The results indicate that the distributions of these populations derived from the crosses of the same female parents and different male parents exist different. Although the distributions appear like the same type such as bimodal or unimodal,they also have striking differences.The results observed from F3 plant lines illustrated that the unimodal type population,like the bimodal type,could also produce homozygous sterile plants in F2 generation.According to the number of F3 sterile lines,it is estimated that the sterile homzygotes are of about 4%. The majority lie in the intervals,in which the seed set rates are less than 40%. On the other hand,only about 50% of lower seed set plants in the bimodal type populations eventually form F3 sterile lines.Authors conjectured that besides the main genotype and environmental condition,the phenotypic value of PGMS progeny plant will be deeply influenced by the composition and state of fertile genes within the progenitors.更多还原