青藏高原老芒麦和垂穗披碱草SSR分子标记鉴别

Distinguishing Elymus nutans from Elymus sibiricus in Qinghai-Tibet Plateau using a SSR marker

垂穗披碱草(Elymus nutans)和老芒麦(E.sibiricus)是青藏高原高寒区广泛种植的优质牧草草种,由于生态适应性变异,在对一些野生种质资源鉴定中,二者常易混淆。为了区别鉴定垂穗披碱草和老芒麦,本研究结合细胞学鉴定,利用不同来源的老芒麦和垂穗披碱草种质材料,对源于普通小麦(Triticum aestivum)的42对SSR引物进行筛选。结果表明,筛选出的小麦EST-SSR引物Xcwem38c在垂穗披碱草中的多态性标记可以有效区分垂穗披碱草和老芒麦。

Elymus nutans and E. sibiricus, which belong to Elyrnus genus of the Triticeae, are perennial herbaceous plants. These two species are high-quality forage grasses which wildly planted in China, espe-cially in alpine zone of Qinghai-Tibet Plateau. Due to eco-adaptive variation, it was often confusing while i- dentifying some wild germplasms between them. In order to distinguish E. nutans from E. sibiricus, mate-rials collected from Sichuan, Gansu and Tibet and somewhere else were screened using 42 SSR primers, including 21 genomic SSR and 21 EST-SSR, which located on the 21 chromosomes of wheat. The results showed that a EST-SSR primer Xcwem38c could produce 3 bands in E. nutans and 1 band in E. sibiricus in PCR system. It indicated that the band with 100 bp presented in both E. nutans and E. sibiricus, while two contiguous bands with 150 bp were only existed in E. nutans. Thus, the two bands could be used to distin- guish E. nutans from E. sibiricus. At the same time, the results obtained from further cytological identifi-cation study were consistent with the molecule marker, which supported the conclusion that the EST-SSR primer Xcwem38c could he used to distinguish E. nutans from E. sibiricus effectively.