Effects of different temperatures on growth and ergot alkaloids concentrations of Achnatherum inebrians seedling-Epichloё sp. seedling

study was conducted to investigate the effects of different alternate temperatures (8 ℃/5 ℃, 15 ℃/12 ℃, 22 ℃/15 ℃, 28 ℃/25 ℃, 35 ℃/28 ℃) on variations of growth and ergot alkaloids concentrations of Achnatherum inebrians associated with Epichloё sp seedling. The results showed that the plant height, root length and biomass of A. inebrians had peak value under 22 ℃/15 ℃, and the plant height had significant differences (P<0.05) with the other four treatments; the root length with treatment of 22 ℃/15 ℃ was significant higher (P<0.05) than that with treatments of 28 ℃/28 ℃, 25 ℃ and 35 ℃/28 ℃; biomass with treatment of 22 ℃/15 ℃ was significant (P<0.05) higher than that with treatments of 8 ℃/ 5 ℃,28 ℃/25 ℃ and 35 ℃/ 28 ℃. The tiller number of A. inebrians had peak value under 15 ℃/12 ℃,and was significantly (P<0.05) higher than that with treatment of 8 ℃/5 ℃,28 ℃/25 ℃and 35 ℃/28 ℃. Chlorophyll was maximum under treatment of 15 ℃/22 ℃, and was significant higher (P<0.05) than that with treatments of 8 ℃/5 ℃,15 ℃/12 ℃and 35 ℃/28 ℃. Soluble sugar had no significant difference between these five temperature treatments. The contents of ergine and ergonovine had a peak value under 22 ℃ / 15 ℃ after 15 d,which had significant difference (P<0.05) with other treatments. In conclusion, the optimal temperature for seedling growth and the accumulation of ergine and ergonovine treatment was 22 ℃/15 ℃.