中文摘要：

从变异黄芪种子中分离并纯化内生真菌,应用ɑ-甘露糖苷酶抑制法检测能产生苦马豆素的内生真菌。提取真菌DNA,扩增和测定真菌ITS和GPD序列,进行序列同源性比较,构建系统发育树。结果：从变异黄芪种子中共分离到3株产苦马豆素内生真菌,其形态特征均与波状芽管蠕孢属相近;ITS和GPD序列与棘豆波状芽管蠕孢一致性高达99%;遗传分析显示,3株菌与棘豆波状芽管蠕孢真菌遗传距离最近。根据形态特点和遗传进化分析结果,将该3株菌鉴定为棘豆波状芽管蠕孢。

英文摘要：

This experiment was performed to isolate and identify fungal endophytes from Astragalus variabills Bunge. The chemical composi-tions of isolated fungi were detected by α-Mannosidase inhibition method. The fungal DNA was extracted from mycelia. The ITS and GPDsquences of the fungi were amplified and sequenced. Homology comparison was conducted and phylogenetic tree was established based on thesequences of the fungi. The results indicated that the three isolates fromA. variabillsBunge were cultured and determined to synthesize swain-sonine. The morphological characteristics was similar withUndifilumspp. The results of homology comparison showed that the sequences fromITS and GPD are nearly identical（99%）. The phylogenetic trees showed that the endophytes are more closely related toU. oxytropis.Three i-solates producing swainsonine fromA. variabillsBunge were classified asU. oxytropisbased on the above-mentioned results.