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F_2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F_2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－1~2的配子明显减少，只占总受精配子的41．4％±2．8％。而另4个F_2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。 The isolation of Pgi-1 isozymes on chromosome 3 was analyzed using F_2 hybrids of indica rice varieties and Japonica rice varieties or japonica rice varieties with wide compatibility. Among them, four F_2 clones showed significant or very significant deviations from the normal Mendelian segregation ratio. The number of gametes with the japonica marker gene Pgi-1-2 was significantly reduced, accounting for only 41.4% ± 2.8% of the total fertilized gametes. While the other four F_2 groups maintained the normal separation ratio. The results showed that the abnormal segregation of Pgi-1 was not related to female fertility, nor was it due to pollen morphological abortion. In the vicinity of Pgi-1 on chromosome 3, there was a new one that was independent of ga-2 and ga-3 Gametophyte gene, control pollen fertilization competition. At the gametophyte locus, alleles possessed by some Japonica or japonica-wide compatibility varieties can eliminate the abortion of japonica gametes due to competition in fertilization in progenies of indica and japonica.