Comprehensive evaluation of drought resistance in six Elymus breviaristatus accessions from the Northwest Plateau of Sichuan Province at seedling stage

Drought tolerance of six Elymus breviaristatus accession samples from the Northwest Plateau of Sichuan Province was investigated over 21 days using a water-controlled potting experiment. Relative water content (RWC), relative electric conductivity (REC), content of proline (Pro), content of chlorophyll (Chl), content of malondialdehyde (MDA), activity of superoxide dismutase (SOD), and peroxidase (POD) of leaves were measured in the control (CK, without drought stress), and on the 7th, 14th, and 21st days after drought stress treatment, respectively. Additionally, drought resistance of germplasms was evaluated using subordinate function analysis. Our results showed that drought stress had significant effects on physiological indices (P<0.05), and significant differences in phenotypic values were observed between drought treatments and the control (CK) (P<0.05). There was also a significant difference detected between the different accession samples (P<0.05). With the extension of drought stress time, RWC and Chl followed a declining trend. By contrast, MDA, REC, Pro and the activity of POD followed a significant rising trend. The activity of SOD increased at first and then decreased. Based on the subordinate function analysis of seven physiological characteristics, the rank order for drought resistance among these E. breviaristatus accessions were as follows: 205176>205133>Red 10-5>204290>Red 6-5>205104.