Isolation Of Endophytic Fungi From Medicinal Plants And Screening Activity Strains Against Pathogenic Fungi

Endophytic fungi are known to establish a harmonized relationship with reservoirsduring the long run of parasitism in the plant microecosystem in medicinal plants.They are rich in abundant secondary metabolites with bioactivities includingantifungal, antitumor, insect disinfestation, immunoregulation, promoting plantgrowth and other biological activity. It makes endophytic fungi an important sourcefor screening bioactive components and lead compounds, which have potentialapplication value in many areas such as industrial fermentation, biological pharmacyand agricultural production.In this study, a variety of medicinal plants were collected from different districts forthe isolation of endophytic fungi, screening endophytic fungi against plant pathogenfrom separated endophytic fungi and identifying antifungal activity of the strains inmorphology and molecular biology. The compound with antifungal activity was alsoextracted and identified and the results we concluded are as follows.Medicinal plants such as Panax ginseng、Fritillaria ussuriensis Maxim、Coptischinensis、Narcissus tazetta、Lonicera japonica、Isatis indigotica、Aloe vera、Belamcanda chinensis、Oenothera erythrosepala、Saponaria officinalis、Rhodiola L.、Astragalus membranaceus、 Lilium、Gastrodia elata Blume were collected fromFusong, Baishan, Changchun, Chengdu, Tangshan, Wuhan.222strains of endophyticfungi were isolated by designing and optimizing the culture medium, then preserved.We used the plate confrontation to screen endophytic fungi against Setosphaeriaturcica, Sclerotinia sclerotiorum, Aspergillus fumigatus, Fusarium oxysporum,Magnaporthe Oryaze, Cercospora zeae-maydis, Fusarium oxysporum, Cylindroca-rpon destructans, Pythium spp. and Botrytis cinerea. As a result, there are29strainswhich appeared obvious inhibitory function upon at least one plant pathogenic fungus.Among them, the strains of Cc-3and Cc-7isolated from Coptis chinensis had broad spectrum and strong antifungal effect against plant pathogenic fungi, especiallyagainst Exserohilum turcicum and Sclerotinia scleroterum.The29stiains of endophytic fungi above were identified by morphological andmolecular biological methods. The results show that they are Chaetomium globosum,Termitomyces sp., Fusarium sp., Paraphoma radicina, Penicillium turbatum,Cadophora sp., Epicoccum nigrum,Alternaria tenuissima, Leptosphaeria sp.,Pleosporales sp., Aspergillus fumigatus, Phoma multirostrata, Cryptosporiopsisericae, Colletotrichum fioriniae, Uncultured Mortierella clone, Mortierellaalpina,Cadophora sp., Colletotrichum gloeosporioides, Talaromyces pinophilus. Thestrain of Cc-7was Cryptosporiopsis ericae and the strain of Cc-3was Phomamultirostrata.By means of antifungal analysis of mycelium and secondary metabolites of Cc-3and Cc-7, we confirmed that both the two strains can produce substances withantifungal activity. It was identified that the volatiles were tetramethylbenzeneproduced by Cc-3and the active compound produced by strains of Cc-7wasπCaryophylleneC15H24.This study firstly reported that tetramethylbenzene produced by Cc-3strain ofPhoma multirostrata inhibits the growth of a variety of plant pathogenic fungi. Also,the mycelium and the Cc-7broth of Cryptosporiopsis ericae can inhibit10kinds ofplant pathogenic fungi, which reflects upstanding activity and broad-spectrumantimicrobial activity. The antifungal effect of Cc-7was determined on corn leavesand tomato leaves under in vitro conditions for first time which provides scientificand theoretical basis for the bio-control of Corn Leaf Blight and Setosphaeria turcica.Therefore, endophytes from medicinal plants can be used as an important source ofdeveloping potential beneficial neotype official compounds.