花苜蓿抗旱耐盐EST—SSR标记筛选

为了给花苜蓿（Medicago ruthenica Trautv．）抗旱耐盐的生态适应性研究提供特异的遗传标记，在已公布的70对鹰嘴豆抗旱耐盐EST—SSR标记中筛选出稳定性好、多态性高的8对引物，并用这8对引物对挑选出的11个居群的286个个体进行扩增，获得111个等位基因。平均等位基因数为13．88；平均观察杂合度为0．497；平均预期杂合度为0．687；多态信息含量从0．313到0．883不等，平均值为0649。以上结果表明，筛选出来的8个EST—SSR标记可以用于花苜蓿的遗传多样性分析，而且遗传多样性处于较高水平。多态性丰富的EST—SSR引物适用于花苜蓿生态适应性进化分析，对揭示花苜蓿抗旱耐盐基因型的遗传变异和地理分布格局以及探讨花苜蓿抗旱耐盐的适应性分化机制有重要意义。

Screening of Drought-and Salinity-responsive EST-SSR Markers in Medicago ruthenica Trautv.

To provide genetic markers for the study of ecological adaptability to responsive drought-and salinity-stress for Medicago ruthenica Trautv., we selected eight pairs of good polymorphism and high stability primers from 70 pairs of drought-and salinity-responsive EST- SSR markers published for chickpea. DNA sequences were amplified with eight pairs of SSR primers by SSR-PCR technique. One hundred and eleven alleles were detected, on average, 13.88 alleles were detected per site. The mean values of observed heterozygosity and expected heterozygosity were 0.497 and 0. 687, respectively. Polymorphism information content value ranged from 0. 313 to 0. 883, and the mean value was 0. 649. These results indicate that the eight EST-SSR markers can be used to estimate genetic diversity of M, ruthenica, and genetic diversity was at a high level. Polymorphism EST-SSR markers can be used to investigate ecological adaptive evolution. The results contribute to revealing the genetic variation of drought- and salt-tolerance genotypes and understanding the distribution pattern and ecological adaptation mechanism of M. ruthenica populations.