Morphological And Molecular Identification Of Endophyticfungi Strain C1Y74from Stellera Chamaejasme And Degradation On Its Host Compounds

The plant Stellera Chamaejasme L (Thymelaeaceae) is perennial herbal. It is toxicwhich can cause livestock poisoning and pregnant female miscarriage, severe cases canresult in death. S. Chamaejasme can produce amount of seeds, have strong vitality, competewith grass for fertilizer, water and light, thus inhibiting the growth of forage grass, resultinga vicious cycle of grassland ecosystem to accelerate the deterioration of natural grassland.At present, it is still difficult to control S. chamaejasme in the grassland. Although the effectof chemical control is conformed, the potential harm on the environment is also existed.Endophytic fungi are fungi which spend the whole or part of their life cycle inside thehealthy plant tissues without any discernible infectious symptoms. They are mutualism thatthe plant provides nutrition to endophytic fungi, and metabolites of endophytic fungi canstimulate plant growth and improving plant resistance. It can conclude that the toxic plantsmay be biodegradable toxic components by its endophytic fungi. In order to provide newinformation and new ideas to use to of S. chamaejasme and grasslands and other toxicplants detoxification of the test by an endophytic fungi isolated from S. chamaejasmedegradation of the host flavonoids and coumarins. The results were as follows:1. The morphological and molecular biological identification of endophytic fungistrain C1Y74from S. chamaejasme: From colony morphology and morphology wereanalyzed, endophytic fungi strain C1Y74preliminarily identified as Aspergillus surroundsubgenus, yellow Green Group (Aspergillus section Flavi). The method of extract DNA isCTAB, and the testing of DNA purity, determination of the A₂₆₀/A₂₈₀=1.86, concentrationis50.5ng/μL.The extraction efficiency is higher. Being took strain C1Y74genomic DNAas the template and specific primers of ITS1/4as the primers, a602bp DNA fragmentwhose GenBank accession number was JN648706that was amplified. BLASTn analysisshowed that the sequence with Aspergillus ITS sequences with high origin, to prove that theamplified fragment is indeed the ITS sequences. The result of morphological identificationis just same as the molecular identification of, it can conclude that strain C1Y74isAspergillus flavus. 2. Study on degradation of host flavonoids and coumarins by endophytic fungistrain C1Y74from S. chamaejasme: The spore suspension of the endophytic fungi wasincubated to the PDA culture medium with adding the extract of S. chamaejiasme as maincarbohydrate source, and the content of residual flavonoids and coumarins in the culturalsystems was determined by ultraviolet-visible spectrophotometer, and the degradationeffects of the initial inoculum size (10%,20%,30%), initial pH (5,6,7,8,9,10),additional carbon source (glucose,0,0.2%,0.5%,1.0%,1.5%,3.0%) and surfactant (Tween80,0,1%,2%,3%,4%) were investigated. At the3rdday, the degradation effects offlavonoids and coumarins were obvious, and the content of the residues was432.24mg/Land1.25mg/L, respectively, which was significantly lower than that of the control group(474.68mg/L and1.61mg/L). At the12thday, the volume of that was303.78mg/L and0.43mg/L, respectively. The orthogonal experiment results showed that the strains C1Y74optimal conditions of degradation in Stellera chamaejasme extract flavonoids as follows:10%of the inoculum size, pH=5, the glucose concentration of0.5%and Tween80concentration of2%, the impact of various factors were as follows: pH> inoculum size>glucose concentration> Tween80concentration, the degradation rate is81.23%, strainsC1Y74optimal conditions for degradation of extract coumarins as follows:20%of theinoculum size, pH=7, the glucose concentration of1.0%and Tween80concentration of2%,the impact of various factors were as follows: Tween80concentration> glucoseconcentration> pH> vaccination, the degradation rate is89.21%.