中文摘要：

以我国内蒙古草原常见优势种羊草（Leymus chinensis（Trin．）Tzvel．）及克氏针茅（StipakrytoviiRoshev．）为实验材料，在离体器官和整株植物水平上探讨内生真菌感染是否会影响宿主植物羊草对克氏针茅种子萌发的作用。实验结果表明：内生真菌感染能够影响羊草对克氏针茅种子萌发的作用，其影响程度与羊草的作用部位、处理方法以及处理浓度相关。与未染菌羊草相比，染菌羊草绿叶在低浓度处理下显著促进了克氏针茅的萌发，高浓度下显著抑制了克氏针茅的幼根生长；染菌羊草枯叶显著抑制了克氏针茅幼根的生长，而染菌羊草地下部显著促进了克氏针茅的萌发；感染和不感染内生真菌的整株羊草对克氏针茅的发芽率和发芽速度无显著影响。在处理浓度相同的情况下，草粉对克氏针茅种子萌发的抑制作用比浸提液处理更为显著，绿叶比枯叶抑制作用更为显著。

英文摘要：

Leymus chinensis and Stipa krylovii, two dominant species in the Inner Mongolia Steppe, were used as the experimental materials. The aim of this study was to test whether endophyte infection of L, chinensis would in- fluence seed germination of S. krylovii when treated with organs in vitro or the whole plant. The results showed that endophyte infection Could change the effects of host plant L. chinensis on seed germination of S. krylovii, the effect was related to grass organs, treatment methods and concentrations. Compared with endophyte-free （E - ） leaves, endophyte-infected （E ＋ ） green leaves significantly increased seed germination rate of S. krylovii in low- er concentration while decreased radicle growth of S. krylovii in higher concentration. E ＋ dead leaves could re- duce radicle growth of S. krylovii more than E - leaves while E ＋ rhizome increased the germination rate more than E - leaves. As for the whole plant, endophyte infection had no significant effect on seed germination of S. krylovii. When treated with the same concentration, grass powder exhibited a stronger reduction in seed germina- tion and seedling than water extract, and green leaves exhibited a stronger reduction in seed germination and seedling growth than dead leaves.