Seed germination and biochemical responses of two Elytrigia elongata accessions exposed to abiotic stresses

Elytrigia elongata, a rhizomatous and sparse-type perennial herb of the Triticeae tribe, with stronger drought and salt tolerance, is an important wild genetic resource for wheat variety improvement. However, no precise information about seed germination and biochemical responses of this species to drought, salinity and mixed saline–alkaline stresses is available. Hence, this experiment was conducted to investigate the effects of three abiotic stresses on seed germination and physiological characteristics of two E. elongata accessions. The results showed that drought and mixed saline–alkaline stresses impair seed germination and bud seedling growth of E. elongata. However, seed germination and bud seedling growth were promoted by 50 mmol/L, but inhibited by 100–200 mmol/L salinity treatments. The malondialdehyde (MDA) content was increased and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the bud seedlings were significantly increased (p <.05) with increasing osmotic stress from 0 to −0.4 MPa, and salinity and mixed saline–alkaline from 0 to 150 mmol/L, but reduced at −0.75 MPa osmotic stress and 200 mmol/L salinity and mixed saline–alkaline stresses. Under the same salinity and mixed saline–alkaline treatment, the activities of SOD and CAT of EE030 were higher than those of EE024 except in 200 mmol/L salinity treatment; however, the MDA content of EE030 was lower than that of EE024, except in 150 mmol/L salinity treatment. In conclusion, the results of this study demonstrated that E. elongata seeds are more tolerant to salinity stress than to drought and mixed saline–alkaline stresses, and EE030 seed are more tolerant to three abiotic stresses than are the seeds of EE024.