张雷 汪霞 李相汉 贡长怡 张立新

摘要 ：2017年-2018年在安徽省庐江、东至县茶园种植区发现一种茶树新病害——梢枯病，发病症状表现为顶芽枯死，嫩叶叶柄变褐，叶片枯萎。为明确庐江、东至县茶树梢枯病的病原菌，采用平板划线法和稀释涂布平板法分离病原，按照柯赫氏法则对病原细菌进行致病性测定，并利用细菌的表型特征和分子生物学技术确定病原菌的分类地位。结果表明，从茶树患病叶片和茎干分离到菌落形态一致的细菌菌株共16株，选择6株代表性菌株进行回接试验，确定获得的细菌分离物为该病害的致病菌;通过对测试菌株的生理生化试验、16S rDNA 和16S23S rDNAITS的序列分析，以及基于16S rDNA、16S23S rDNAITS序列的系统发育树分析，将安徽省茶树梢枯病的病原菌鉴定为燕麦嗜酸菌燕麦亚种Acidovorax avenae subsp. avenae。

关键词 ：茶树; 梢枯病; 鉴定; 燕麦嗜酸菌

中图分类号：

S 435.711文献标识码： A

DOI： 10.16688/j.zwbh.2019627

Identification of the pathogen Acidovorax avenae subsp. avenae causing shoot blight of Camellia sinensis

ZHANG Lei， WANG Xia， LI Xianghan， GONG Changyi， ZHANG Lixin*

（College of Plant Protection， Anhui Agricultural University， Hefei 230036， China）

Abstract ：A new shoot blight disease of tea plant was found in several tea plantations located in Lujiang and Dongzhi counties of Anhui province from 2017 to 2018. Symptoms initially appeared on the young shoot with watersoaked spots， and then the spots merged into large patches when the disease further developed. Symptoms of young leaf blight could be observed three weeks later. In order to clarify the pathogen associated with the tea shoot blight， the isolates were recovered from diseased samples and determined by using phenotypic characteristics combined with molecular identification. The results showed that 16 bacterial colonies with white color were consistently isolated from symptomatic leaves and stems， and six representative isolates were selected and confirmed to be the causal agent of this disease according to the Kochs postulates. The pathogen was further identified as Acidovorax avenae subsp. avenae based on the physiological and biochemical tests， sequence analysis of 16S rDNA and 16S23S rDNA internally transcribed spacer region， along with phylogenic analysis of 16S rDNA and 16S23S rDNAITS sequences from the tested isolates and reference strains of Acidovorax spp.

Key words ：Camellia sinensis; shoot blight; identification; Acidovorax avenae subsp. avenae

茶樹原产于中国，为多年生常绿木本植物，多分布于亚热带和热带地区。茶树作为一种重要的经济作物被广泛种植，且是世界上最受欢迎的饮料作物[1]。中国是最早开始种植茶树的国家之一，种植的茶树品种类型多样，跨越多个省份。安徽省兼具南北气候特点，其茶园种植区是中国重要的茶区之一[2]。在茶树生长的过程中，茶树的叶和芽会受到许多病害的影响，包括炭疽病、白星病、云纹叶枯病、芽枯病[34]。近年来，随着茶园面积不断扩大、气候环境的改变，一些新的病害逐渐增加并被发现[5]。2017年-2018年，在安徽省茶园种植区……