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

Elymus nutans and E.sibiricus, which belong to Elymus genus of the Triticeae, are perennial herbaceous plants. These two species are highquality forage grasses which wildly planted in China, especially in alpine zone of QinghaiTibet Plateau. Due to ecoadaptive variation, it was often confusing while identifying some wild germplasms between them. In order to distinguish E.nutans from E.sibiricus, materials 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 distinguish E.nutans from E.sibiricus. At the same time, the results obtained from further cytological identification study were consistent with the molecule marker, which supported the conclusion that the ESTSSR primer Xcwem38c could be used to distinguish E.nutans from E.sibiricus effectively.