Detection of swainsonine and isolation of the endophyte Undifilum from the major locoweeds in Inner Mongolia

Abstract Locoweeds are Astragalus and Oxytropis species that contain the toxic alkaloid swainsonine, causing widespread poisoning of livestock in Inner Mongolia. Taxa ( Astragalus , Oxytropis , Sphaerophysa , and Sophora species) suspected of causing locoism and/or poisoning in Inner Mongolia were surveyed for swainsonine and Undifilum , the fungal endophyte responsible for the production of swainsonine. Swainsonine was detected at concentrations greater than 0.01% in Astragalus variabilis and Oxytropis glabra . The endophyte Undifilum was detected by culturing and PCR in samples containing swainsonine concentrations greater than 0.01%. In some specimens of A. variabilis and O. glabra swainsonine was not detected or concentrations were less than 0.01%. In these samples the endophyte could not be cultured, but was detected by PCR. Additionally, contrary to previous reports the quinolizidine alkaloids, thermopsine, anagyrine, and lupanine, were not detected in O. glabra and Oxytropis ochrocephala , however the quinolizidine alkaloids, sophoridine, sophocarpine, and sophoramine were detected in Sophora alopecuroides as previously reported.