核桃炭疽病病原菌鉴定及生物学特性

Identification and Biological Characteristics of Pathogen from Colletotrichum gloeosporioides

本文从表现炭疽病症状的核桃果实上分离到一株具有强致病性菌株（TS-09）,并进行了鉴定和生物学特性研究。经形态特征观察、培养性状以及r DNA-ITS、ACT、β-tub2、GPDH四种保守基因序列分析,TS-09菌株为胶孢炭疽菌（Colletotrichum gloeosporioides）。生物学特性测定结果表明：TS-09菌株在PDA培养基上生长最好;25~30℃之间适宜菌株生长及产孢,28℃是菌株最适宜的生长及产孢温度;弱酸性环境（p H4.0）有利于产孢,中性环境（p H7.0）适宜菌丝生长;长时间光照抑制菌丝生长,黑暗条件有利于菌丝生长;菌丝的抗逆性较强,60℃处理15 min、62℃处理10 min,菌丝死亡。研究结果将为核桃炭疽病的预测及有效控制提供理论依据。

Walnut anthracnose disease is a kind of serious disease of walnut all over the world. In this paper, the identification and the biological characteristics of strain TS-09 isolated from the walnut fruits were studied. The results showed that the strain TS-09 was identified as Colletotrichum gloeosporioides based on its morphologic characters, cultural characteristics and four conserved genes（ribosomal DNA-ITS, ACT, β-tub2 and GPDH）sequences analysis and the pathogenicity was powerful. For the growth of strain TS-09, the best medium was PDA. The optimum temperature was 28 ℃and the optimum p H for mycelium growth was 7.0. The condition of weak acid was favorable for spore production（p H 4.0）. During continuous illumination, the mycelium growth was inhibited while the condition of continuous darkness was better for mycelium growth. The mycelium had stronger resistance against temperature and the lethal temperature for mycelium was 60 ℃（15 min） or 62 ℃（10 min）. Our research expected to offer theory support for prediction and effective control of walnut anthracnose.