Research on Flowering Habits and Fertility of Gaozhou Common Wild Rice (Oryza rufipogon) in Lingshui of Hainan Province

高州普通野生稻在海南陵水的开花习性和育性研究(英文)

[Objective] The paper was to explore the flowering habits and fertility of Gaozhou common wild rice （Oryza rufipogon Griff.） in Lingshui of Hainan Province. [Method] The flowering habits, pollen fertility and seed setting rate of Gaozhou common wild rice in Lingshui of Hainan Province were studied, and compared with the flowering habits of common wild rice in Hainan Province. [Result] Gaozhou common wild rice was able to flower twice a year. The first flowering stage was from mid-April to mid-June for about 60 d, and the daily peak flowering dates were from May 13 to May 22. The daily flowering time was mainly between 11：20 and 13：00, and the peak flowering was at 11：30. The second flowering stage was from late August to late October for about 45 d, and the peak flowering dates lasted from September 8 to September 18. The daily flowering time was mainly from 11：15 to 12：50, and the daily peak flowering was at 11：30. In both flowering stages, the panicles had the same flowering characteristics. The stigma exsertion reached a high value of 95.37% with single （46.23%） and dual （49.14%） stigmas exsertion respectively. A spikelet remained open for 1.5-2.5 h, the angle of spikelet opening varied from 29.9° to 32.4°. At the two flowering stage the average pollen fertility rates were 89.67% and 85.62%, the average seed setting rates were 58.81% and 55.79%, respectively. Hainan population flowered only once （from mid-October to mid-December）, this had significant difference with the performance of Gaozhou common wild rice which flowered twice a year. [Conclusion] The results provided basis for the research on gene flow frequency from transgenic rice to wild rice and its relationship with flowering habits of common wild rice.

[目的]探讨高州普通野生稻(Oryza rufipogon Griff.)在海南陵水的开花习性和育性。[方法]对广东高州普通野生稻在海南陵水的开花习性、花粉育性和结实率进行了研究,并与海南普通野生稻开花特性进行了比较。[结果]广东高州普通野生稻在陵水1年开花2次,第一开花期在4月中旬至6月中旬,历时约60d,开花高峰期为5月13～22日,日开花历时主要集中在11:20～13:00,日开花高峰在11:30左右;第二开花期在8月下旬至10月下旬,历时45d,开花高峰期在9月8～18日,日开花历时在11:15～12:50,日开花高峰在11:30左右。2次开花期间的颖花开放特性基本相同,柱头外露表现为单露率46.23%,双露率49.14%,柱头总外露率达95.37%。单个颖花从开颖到闭颖一般需1.5～2.5h,开颖角度为29.9°～32.4°。上、下半年2个季次的花粉育性分别为89.67%和85.62%,平均结实率分别为58.81%和55.79%。海南普通野生稻一般1年仅开花1次,开花期在10月中旬至12月中旬,这与高州野生稻在陵水1年开花2次的表现有明显差异。[结论]为研究转基因水稻向普通野生稻基因漂流频率及与普通野生稻的开花习性相互关系奠定了基础。