Abstract: The selfing and outcrossing seeding capability of wildrye (Leymus chinensis)were investigated under the natural environments. The viability of pollens was estimated by the way of FDA fluorescent staining and the developmental characters of pistals and stamina at time and space were observed. The results showed that the selfing setting percentage was far less than the outcrossing setting percentage in the fields. The mean value of viable pollens was above exist temporal and spatial isolation between stigmas and anthers. In addition, thioredoxsin h gene was considered to be related to self-incompatibility in poaceae plants. Using the primers designed from it, the anticipated fragment was detected in the genome of Leymus chinensis by PCR amplification. So, the authors considered that no or much lower selfing seeding percentage may lie in the self-incompatible mechanism under the genetic control in Leymus chinensis,and the thioredoxsin h gene may be related to its self-incompatibility. However, this is only an initial conclusion and much evidence is needed to prove this in cytology and molecular biology.

Key words: Leymus chinensis, Self-incompatibility, Setting percentage, Pollen vigor, Self-pollination, Thioredoxsin h

摘要： 在自然条件下进行羊草自交、异交结实性实验。采用FDA染色法检测羊草小孢子活力,观测雌、雄蕊发育的时空特点。结果表明,在草原上羊草异交结实率远大于其自交结实率。在成熟花药中有生活力的花粉平均达95.2%以上。在发育时间顺序和空间结构上,雌、雄蕊并不妨碍自体授粉。另外,利用禾本科植物自交不亲和性(SI)有关的硫氧还蛋白h基因设计的引物在羊草DNA中检测到预期片断。因此,笔者认为,羊草自交不结实或结实率低的主要原因可能在于基因控制下的自交不亲和反应机制,硫氧还蛋白h基因可能与羊草的自交不亲和性有关。这仅为初步结论,仍需在细胞学和分子生物学方面取得更多的依据。

关键词: 羊草, 自交不亲和性, 结实率, 花粉活力, 自花授粉, 硫氧还蛋白h