Isolation and Identification of Colletotrichum gloeosporioides in Pears and Its Biological Characteristics

Objective] This study aimed to explore the biological characteristics of Col etotrichum gloeosporioides in pears. Method] Twenty-five C. gloeosporioides strains were isolated and identified from the diseased samples. Their pathogenicity was identified by inoculating the surface of punctured pears with fungal discs. The effects of different temperatures, pH values, carbon sources and nitrogen sources on the growth of C. gloeosporioides mycelia were explored by incubating fungal discs on the center of plates. Result] Among the twenty-five C. gloeosporioides strains, three had strong pathogenicity, and eighteen had intermediate pathogenicity, and four strains had weak pathogenicity. Those highly-pathogenic strains had darker colonies, with dense mycelia, whereas those lowly-pathogenic ones had white colonies, with sparse mycelia. Those with fast-growing colonies showed strong pathogenicity, while those with slowly-growing colonies displayed weak pathogenicity. There was no relationship between conidia yield and pathogenicity. The optimum temperature for the growth of C. gloeosporioides mycelia was 25-30 ℃, and the optimum pH was 5.0-7.0. C. gloeosporioides could make use of various carbon sources （monosaccharide and disaccharide）, inorganic and organic nitrogen sources, and the optimal carbon source and nitrogen source were sucrose and beef extract, respectively. Conclusion] Our study benefits further understanding of C. gloeospori-oides and helps to control pear anthracnose more effectively.