关键词: 小花棘豆, 内生真菌, 苦马豆素, 层出镰刀菌, 疯草

Abstract: To screen and obtain swainsonsine-producing endophytic fungi in Oxytropis.flabra, explore the relationship between endophytic fungi and swainsonine toxin in Oxytropis.flabra． In this research, we isolated and purified endophytic fungi of 6 Oxytropis.flabra samples from the west Inner Mongolia. Swainsonine was detected by thin layer chromatography and gas chromatography in fermentation liquor of the isolated fungus, then screened the Swainsonsine-producing endophytic fungi. Combined colonial morphology and micro-morphology to identify the species of isolated fungus. Finally got 6 species of endophytic fungi through identification. 2 of the 6 species endophytic fungi can produce swainsonine, named them XJ-J-1 and XJ-H-1 respectively. The Swainsonine yield was determined by gas chromatography, 4.209 2 mg·L^-1 in the fermentation liquor of XJ-J-1 and 16.733 8 mg·L^-1 in the fermentation liquor of XJ-H-1. The 2 strains endophytic fungi have the same genotype but different phenotype, both of them are Fusarium proliferatum.The results show that the swainsonine-producing endophytic fungi can be isolated from the Oxytropis.flabra .

Key words: Oxytropis.flabra, endophytic fungi, swainsonine, fusarium proliferatum, locoweed