Study On Relationship Between Swainsonine And Fungal Endophytes In Oxytropis Ochrocephala Bunge

Oxytropis ochrocephala Bunge which contains toxic substance distributes in theqinghai-tibet plateau alpine meadow widely, the toxic substance-swainsonine cancause livestock poisoning and dying causing the development of animal husbandry isseriously blocked,meanwhile,O.ochrocephala has high nutritional value,so there is alarge application prospect in forage development.Therefore,the research on theswainsonine change and producing mechanism has important theoretical significanceand application value.In this study,the swainsonine(SW) contents of Oxytropis ochrocephala Bunge invarious parts at different stages were detected by gas chromatography,meanwhile,nutritional ingredients and mineral elements of different growing stages were detectedby nutritional ingredient and mineral element analysis;combined colonial morphologyand micro-morphology to identify the isolated fungi from various parts at differentstages,and cultured the endophytic fungi by liquid fermentation,finally,theswainsonine contents of hyphae and cultures were detected by GC.The primaryobjectives of the study were to know the relationship between swainsonine andfungal endophytes in Oxytropis ochrocephala Bunge,provide basement theoryfor controlling locoism and utilizing locoweed.The main results are as follows:1.Swainsonine content of Oxytropis ochrocephala Bunge at different growthstages are different,the SW contents in aboveground part at pod bearingperiod>florescence>withering period>bud formation,the SW contents at pod bearingperiod is48.19mg.kg-1；swainsonine content of Oxytropis ochrocephala Bunge indifferent parts are different,SW contents in pods>flowers>leaves>stems>root,the SWcontents in pods is107.787mg.kg-1.2.The contents of CP、CA、NFE and Ca are the highest at bud formationstage，The contents of CP is second only to Medicago sativa L. 3.There are78fungal isolates from different parts at different growth stages ofOxytropis ochrocephala Bunge,they be classified into7genera,including Undifiliumsp.,Fusarium sp.,Colletotrichum sp.,Epicoccum nigrum sp.,Phoma sp.,Phialophorasp.,Exophiala sp.,one is uncultured fungus.4.The swainsonine was detected in the10fungi of Undifilium sp.,it shows thattoxic substance swainsonine is from endophytic fungi of Undifilium sp.in Oxytropisochrocephala Bunge.5.Swainsonine contents in different parts of Oxytropis ochrocephala Bunge andhyphae of endophytic fungi were positively correlated.