栽培稻与其野生近缘种的可交配性研究

通过人工授粉方法研究栽培稻与二倍体和四倍体野生稻之间的可交配性.以栽培稻为对照,用光学显微镜观察不同野生稻花粉在同一栽培种柱头上的萌发生长情况.结果表明,在栽培稻柱头上普通野生稻(AA)花粉萌发最好,与对照萌发情况相近.药用野生稻(CC)萌发差,表现为柱头上花粉附着量少,开始萌发时间迟,萌发量少,花粉管扭曲、缠绕、伸长慢等.四倍体野生稻未观察到有萌发现象.说明普通野生稻与栽培稻亲缘关系近,可交配性好;药用野生稻与栽培稻可交配性差;四倍体野生稻与栽培稻可交配性极差.由此推断,转基因水稻与普通野生稻通过花粉途径发生基因漂移的可能性很大,而与药用野生稻和其他基因组野生稻发生基因漂移的可能性很小.

Cross-compatibility between Cultivated Rice and Its Wild Relatives

The cross-compatibility between cultivated rice and 6 diploid and tetraploid wild rice species was studied st W gm th at by means of artificial pollination. The germination and growth of different wild rice pollen grains on the a of the same cultivated rice were observed with optical-microscope, and the cross results were compared those of cultivated rice at the correspon Oryza rufipogon pollen grains were similar to g time. The results showed that the germination and growth of those of cultivated rice. The pollen grains germinated quickly, after cross. For instance, few numbers of pollen grains adhered to the stigmata; the time when germination started after cross was delayed; few numbers of pollen grains germinated; some pollen tubes failed to enter the stigmata, they just twined or circled on the surfaces of the stigmata after germination; Some pollen tubes could enter the stigmata and grew slowly. No germination was observed in the tetraploid wild rice. According to the results, the relationship between O. rufipogon and cultivated rice is relatively close, and they had good crosscompatibility. On the other hand, O. officinalis and cultivated rice had bad cross-compatibility. It could be concluded that potential gene flow between transgenic rice and O. rufipogon was very large, and was very low between transgenic rice and O. officinalis or other wild rice species.