Indentification Of Pathogens Causing Apple Bitter Rot And Grape Ripe Rot In Shaanxi Province

As a worldwide agricultural fungal diseases, plant anthracnoses cause seriously economic loss and attract universal attentions of global researchers. Many plant anthracnose pathogens often attributed to Colletotrichum gloeosporioides and to C. acutatum. Colletotrichum gloeosporioides was reported to infect more than 1000 plants. Recently, the strict species concept of C. gloeosporioides was confirmed by combined morphological characters with molecular data. To understand the pathogen constitution caused by Colletotrichum on apple bitter rot and grape ripe rot in Shaanxi province, we colleted samples from 10 sites of planting apples and 11 sites of planting grapes, and identified them by morphological, cultural and pathogenic characters, multi-genes phylogeny analyses The results as follows.1. More than 400 samples of apple bitter rot and grape ripe rot were collected in Shaanxi province. They were isolated by tissue isolation or picking off spore masses with a sterilized wire loopt from diseases parts. We got 100 pure cultures of apple bitter rot and 98 from grape ripe rot. Pathogenicity were conformed by Koch’s postulate.2. It was found that the isolates of apple bitter rot were identified as four species: Colletotrichum fioriniae,Colletotrichum fructicola,Colletotrichum hymenocallidis and Colletotrichum siamense. They are all new pathogens of apple bitter rot around the world. Of these species, C. fioriniae, C. fructicola and C. siamense were new records species for China.3.The isolates of grape ripe rot was clustered into 4 clades and identified as four species. Three of them treated as new species and ,named as Colletotrichum jiangzeis, Colletotrichum meixiane and Colletotrichum vitise. Another species,C. fioriniae was firstly found on grape.4. In our examined specimens the typical C. gloeosporioides and C. acutatum (strict sense) were not found both in the isolates of apple bitter rot and grape ripe rot, it is possible that the two species are not the pathogen of apple and grape.5.The same specie, C. fioriniae was found from apple and and grape, there is potential that each host is infection sources for others in natural conitions. 6.The method of multi-genes phylogeny analyses was more efficient to distinguish the similar species than rDNA-ITS.