Biological characteristics of 2 species of Colletotrichum causing Colletotrichum leaf disease.

Colletotrichum leaf disease was caused by Colletotrichum gloeosporioides Penz.and Colletotrichum acutatum Simmonds.Colletotrichum gloeosporioides Penz.was the major pathogen.The biological characters of Colletotrichum gloeosporioides and Colletotrichum acutatum was reported in this paper.The result showed that the optimum temperature of mycelium growth was 28 ℃ for Colletotrichum gloeosporioides and Colletotrichum acutatum.The mycelium growth of Colletotrichum gloeosporioides was the best under light.However,the alternation of light and darkness every 12 hours was found to be the best for Colletotrichum acutatum.The optimum pH range of mycelium was pH 6-8.There were significant differences on the carbon resources between Colletotrichum gloeosporioides and Colletotrichum acutatum.Colletotrichum gloeosporioides grew well on the media using maltose as the carbon resources and Colletotrichum acutatum grew well on mannitol and lactose.There was obsot obviously differente of the reaction of Colletotrichum gloeosporioides and Colletotrichum acutatum to 70 % thiophanate-methyl,Colletotrichum acutatum had stronger resistance to fungicide.