北疆沿天山北坡一带葡萄穗轴褐枯病病原菌的鉴定

Identification of the pathogens of grape spike-stalk brown along the Tianshan Mountains

2015年在新疆沿天山北坡一带的‘夏黑’葡萄上,出现了一种果穗穗轴变褐、枯死、幼果萎缩的病害,部分果园发病率达到100%,减产30%~50%。为了查明其发病原因,采用常规组织分离法对发病的穗轴进行了病原分离和纯化,共获得104个链格孢属真菌Alternariaspp.菌株,选取其中10个代表性菌株,通过常规形态学鉴定、致病性测定及核糖体内转录间隔区ITS(ITS1/ITS4)和组蛋白3基因序列分析,结果表明,引起该病害的病原有两个,分别是Alternaria tenuissima和A.alternata,与国内大部分葡萄产区报道的A.viticola不同。

A grape disease which caused brown necrosis of the spike-stalk and fruit shrinkage was observed on ’Summer Black’grape along the Tianshan Mountains in Northern Xinjiang in2015.The disease incidence in some orchards reached 100%,reducing yields by 30%-50%.One hundred and four Alternariaspp.were isolated from diseased tissues to determine the causal agent of the disease.Ten representative isolates were selected for morphological observation,pathogenicity tests,comparison of internal transcribed spacer regions 1 and 4,and histone 3nucleotide sequences.The results showed that A.tenuissima and A.alternata were the causal pathogens of spikestalk brown spot in grape.This was different from previous reports from other regions of China.