ITS Sequenceanalysis,Tissue Isolation,Culture And Antifungal Activity On Lysurus Mokusin

In the study,through the basic research of Lysurusmokusinincluding classification status,distribution,toxicity and other reports,the feasibility of its application as a microbial source fungicide was analyzed.We analyzed ITS sequences of L.mokusin collected in the field and N-J phylogenetic tree was established to determine its classification status.L.mokusin collected in the field were cultured and the optimal medium was optimized.Then we used the growth rate method and inhibition of spore germination method for antifungal activity assay.ITS sequence analysis and construction of N-J phylogenetic tree showed that the collected fungi belonged to the family Haliotisidae,and the genetic relationship was close to the fungus of Dictyophora.Combined with the traditional morphological description,we identified it as Lysurusmokusin.The results of optimal cultureshowed that the optimal medium was potato200g?glucose 20g?peptone 3g?inorganic salt(KH2PO4 1g?K2HPO4 1g?MgSO4 0.5g?CaCl2 0.05g?KCl 0.5g?FeSO4 0.01 g?NaNO3 0.5g dissolved in 1000mL distilled water)10mL?pH=5;the optimum temperature was 20 ?;the net growth of L.mokusin is 7.133cm.The results of antifungal activity assayshowed that the culture medium and its crude extracts both had antifungal activity against three forest pathogens.The inhibitory rates of culture medium on Fusarium oxysporum,Botrytis cinerea and Trichodermamultiflorumwere 45.35%,37.08%and 15.58%,respectively.Effects of 5 kinds of organic solvents as extracting solvents on the net growth of pathogens were n-butanol>ethyl acetate>ether>chloroform>petroleum ether;whenusing n-butanol as extraction solvent,the inhibitory rates of crude extract on F.oxysporum,B.cinerea and T.multiflorum were 45.35%,37.08%and 15.58%,respectively.The results of inhibition of spore germination assay showed that the spore germination rate of F.oxysporum was 72.10%.The inhibitory effects of five kinds of organic solvents on the spore germination of F.oxysporum were ether>petroleum ether>chloroform>n-butanol>ethylacetate,and the spore germination rates were 73.43%,30.46%,28.74%and 25.20%and 16.92%respectively.All the results above showed that the antifungal activity of L.mokusin was significant and had some further research value.This study provided a new theoretical basis for the further study of microbial fungicides.