Identification On Colletotrichum Of Garden Flowers In Pearl River Delta Region

Colletotrichum is a widely distributed genus of fungi, which can cause anthracnose on different plants and result in serious losses to agricultural production. In order to further clarify the species of Colletotrichum on landscape flower plants in Guangdong and provide theoretical basis for the disease prevention and control, Colletotrichum on landscape flower plants in pearl river delta region were collected, isolated and identified using morphological observation and multiple genes analysis. The results are as follow:In 2013~2014, 109 isolates of Colletotrichum were collected and isolated totally from landscape flower plants in Guangzhou, Shenzhen, Dongguan, Foshan and so on. 8 species which belong to 3 complex species were identified through morphological observation and sequence analysis of 8 genes, i.e. ITS, GPDH, TUB2, HIS3, GS, ACT, CAL and apn2/MAT12 igs. They were C. gloeosporioides, C. fructicola, C. fragariae, C. tropicicola and C. theobromicola in the C. gloeosporioides complex, C. siamense and C. hymenocallidis in the C. siamense complex, and C. liriopes in C. graminicola sensu lato. Among of them, C. fructicola, C. hymenocallidis and C. siamense were the dominant species. Alocasia macrorrhizos, Calathea makoyana, Polyscias scutellaria, Disoropsis fuscopicta Hance, Jasmine, Dianella ensifolia, Ananas comosus,Strelitzia reginae, Ixora chinensis Lam, Dendrobium nobile and Cymbidium sinense are new hosts of C. siamense, Daphne odora is a new host of C. liriopes, and Paphiopedilum insigne is a new host of C. tropicicola.The result of molecular systematic analysis showed that ITS could distinguish the C. gloeosporioides complex from the C. graminicola sensu lato, but it could not separate species with close relationship in the C. gloeosporioides complex. For Colletotrichum, the distinguishing effect of ITS was better than that of HIS3 and GS, Although GS could indentify the C. gloeosporioides complex, but HIS3 and GS could not separate species with close relationship in the C. gloeosporioides complex. Moreover, the distinguishing effect of GDPH was better than that of ITS, apn2/MAT12 igs was useful to distinguish between C. siamense and C. hymenocallidis.