Abstract: The segregation of isozyme Pgi-1 on chromosome 3 was examined in eight F₂ populations, rice (Oryza sativa L. ) inter-subspecific hybrids between an indica cultivar and a japonica or a japonica wide compatibility variety. Four populations showed distorted segregation by the transmission ratio of Pgi-1 via the male garnetes from japonica cultivar by 41. 4%±2. 8% instead of the normal 50%, whereas no segregation distortion was ob served in the other four populations. The segregation distortion of Pgi-1 was not related to the spikelet fertility and pollen fertility. It is possible that there was a new gametophyte gene near the locus Pgi-1 on chromosome 3 of those rice inter-subspecific hybrids, and in this locus, some japonica or japonica wide compatibility varieties have an allele which could mitigate the segregation distortion of Pgi-1 when crossed with the indica cultivar.

Key words: gametophyte gene, inter-subspecific hybrid, isozyme, segregation distortion

摘要： 采用籼稻品种与粳稻品种或偏粳型广亲和性品种的杂交后代F₂集团8个，分析了位于第3染色体上的Pgi-1同工酶的分离情况。其中4个F₂集团表现为显著或极显著偏离正常的孟德尔分离比例，带粳稻标记基因Pgi-1的配子明显减少，只占总受精配子的41.4%±2.8%。而另4个F₂集团则保持正常分离比例。分析结果表明， Pgi-1的异常分离与雌性育性无关，也不是由于花粉形态性败育而致，在第3染色体Pgi-1附近，存在一个独立于ga-2和ga-3的新的配子体基因，控制花粉的受精竞争。在该配子体基因位点上，一些粳稻品种或偏粳型广亲和性品种具有的等位基因可以消除籼粳交后代中由于受精竞争而导致的粳配子败育。

关键词: 亚种间杂种, 异常分离, 同工酶, 配子体基因