茶树炭疽病病原鉴定

Identification of anthracnose pathogen in tea plant

【目的】明确福建省福州市茶树炭疽病病原菌种类,为茶树炭疽病的防治及抗病育种提供参考。【方法】采用形态学结合基于谷氨酰胺合成酶(GS)、β-微管蛋白(β-TUB2)、核糖体DNA内转录间隔区(r DNA-ITS)和核糖体DNA大亚基(LSU)等4个基因序列的多基因系统发育分析方法,对从福州市几个茶园不同茶树品种炭疽病典型病叶上分离获得的茶树炭疽病病原菌(FFB、FJG、FRG、FSX和FFA)进行鉴定,并利用柯赫氏法则验证菌株的致病性。【结果】5株供试病原菌均能通过伤口侵染茶树叶片,且病症相似,为茶树炭疽病致病菌。5株病原菌分离物形态特征相似,基于多基因系统发育分析并结合其形态学特征,将5株供试菌株鉴定为Colletotrichum siamense。【结论】C.siamense为茶树炭疽病弱致病菌,主要通过伤口侵染茶树。生产中应尽量避免人为活动造成茶树叶片损伤,以减少茶树发生炭疽病。

【Objective】The present study investigated the species of anthracnose pathogen of tea plant in Fuzhou, Fujian, in order to provide scientific basis for controlling anthracnose and breeding disease-resistant varieties. 【Method】The researchers combined morphology and multiple gene phylogenetic analysis based on gene sequences of glutamine synthetase（GS）, β-tubulin（β-TUB2）, ribosomal internal transcribed spacer（rDNA-ITS） and ribosomal RNA large subunit（LSU） to identify anthracnose pathogen（FFB, FJG, FRG, FSX and FFA） isolated from typical diseased tea tree leaves of different varieties planted in various tea gardens in Fuzhou. Koch＇s postulation was applied to identify pathogenicity of the strains. 【Result】The five strains could infected tea tree leaves through wound, and the symptoms were similar. They were pathogenic bacteria of anthracnose. The isolates of the five strains shared similar morphological characteristics. They were identified as Colletotrichum siamense based on multiple gene phylogenetic analysis and morphology. 【Conclusion】C. siamense is weak anthracnose pathogen of tea plant and mainly infect tea plant through wound. Therefore, during planting, leaves injury caused by human activity should be avoided to reduce incidence of anthracnose.