Studies On Correlated Factors To Swainsonine In Three Oxytropis Species In Inner Mongolia

Oxytropis glabra, Oxytropis aciphylla and Oxytropis racemusa are economic plants with medicinal values. Distributed widely in Inner Mongolia grassland and desert regions, these three species also have important ecological and feeding values. O. glabra is a poisonous plant species to livestock. However, swainsonine, the poisonnous component of O. glabra is a potential anticancer medicament.In this research, swainsonine contents of three Oxytropis species were determined by the high performance liquid chromatography coupled to mass spectrometry. The population genetic diversity was also studied and the swainsonine related molecular markers were screened by ISSR. In vitro fungi cultures from the individual plant of O. glabra were performed and microbiological morphology of the colony and the conidiophore were investigated. The 5.8S rDNA/ITS sequences of fungi amplified from total DNA in both plants and fungal endophytes were studied. These sequences were analysed and compared, and they were also compared to the 5.8S rDNA/ITS sequence of fungal enduphyte Embellisia sp. L12 from the O.lambertii, O.sericea and A.mollisimus distributed in USA. Swansonine content was also compared among populations of O. glabra, O.lambertii, O.sericea and A.mollisimus .The results were as follows:Swainsonine was not found in the populations of O.aciphylla and O. racemes, and the 5.8S rDNA/ITS regions of fungal enduphytes Embellisia sp. were not amplified from the populations of these two species either, so these two Oxytropis species are not locoweeds and they do not cause livestock toxicosis. The 5.8S rDNA/ITS region of Embellisia sp. was amplified from 65 individual plant total DNA among 90 plants in six populations of O. glabra while swainsonine was detected in 51 plants among them. The swainsonine content changed according to different populations and plants. The swainsonine was not found in the OY2 population of O. glabra var. tenuis,but it was found in OY2 population of O. glabra. The 5.8S rDNA/ITS region of Embellisia sp. was not amplified from the O. glabra var. tenuis, and it is probably not poisonnous to livestock.The ISSR loci showed very high polymorphism in three Oxytropis species. The differences among populations were mainly influenced by changes of gene frequencies. The genetic diversities of three Oxytropis species were very high, and the genetic differentiation within population were the main components in the total genetic diversities. No swainsonine specific ISSR marker was found in 6 populations of O. glabra.The studies based on molecular biology and microbiology indicated that the fungal endophytes identified from O. glabra should belong to Embellisia Sp.. Most plants of O. glabra having fungal endophytes corralated to their containing swainsonine. 10 5.8SrDNA/ITS sequences from O. glabra in Inner Mongolia were totally the same. They had only one different base which was in the 5.8SrDNA region in the whole 517 bp sequences. The ITS1and ITS2 regions were highly conserved. The species identification of the fungal endophyte needs to be further studied.