Effects of high temperature treatments on viability of Epichloё seeds of Elymus dahuricus

In the present study,high temperature treatments (60, 70 and 75 ℃) was employed to construct Epichloё-free populations of Elymus dahuricus. The results indicated that high temperature treatments can kill Epichloё endophyte in the seeds. After 75 ℃ for 20 days treatment,the Epichloё endophyte infected rates significantly dropped from 93.17% to 0% (P<0.01), and the germination rate,germinating potential, germination index, vital index and seeding fresh weight of E. dahuricus increased by 36.37%, 73.94%, 50.38%, 63.38% and 7.79%, respectively(P<0.05). Meanwhile, high temperature improved hypocotyls and radical growth and the hypocotyls and radical length of the treated seedlings increased by 0.54% and 14.43%. Therefore, high temperature of 75 ℃ treatment was an effective way to construct Epichloё-free populations of E. dahuricus which provided some academic bases and references for establishing Epichloё-free populations of grass.