Swainsonine-producing fungal endophytes from major locoweed species in China.

Locoweeds including the toxic species of Astragalus spp and Oxytropis spp. are widely distributed in the western region of China and result in a chronic neurological disease known as locoism in animals. To determine the presence of swainsonine-producing fungal endophyte of major locoweed species in China, endophytes were isolated from 8 locoweed species that including A. variabilis, A. strictus, O. glacialis, O. kansuensis, O. ochrocepala, O. sericopetala, O. glabra and O. latibracteata. Seven species of locoweed were confirmed contain substantial amounts of swainsonine and infect swainsonine-producing fungal endophyte. These endophytes were classified as Undifilim oxytropis according to the fungal morphology and phylogenetic analysis based on sufficient ITS sequences. PCR-RFLP analysis of IGS region showed that the interspecific or intraspecific variations were present among the endophytes from different locoweed species.