石河子地区棉花苗期叶斑病病原菌种类鉴定

Identification of Pathogens Causing Leaf Spot Disease at Cotton Seedling Stage in Shihezi Area

【目的】研究石河子地区棉花苗期叶斑病病原菌种类。【方法】棉花苗期,采集石河子地区典型叶斑病样120个,用常规组织分离法进行分离和纯化,共得到105个链格孢属(Alternaria spp.)菌株,选取其中15个代表性菌株,通过致病性测定、常规形态学鉴定及组蛋白3基因序列分析,对病原菌种类进行鉴定。【结果】供试15个代表性菌株均具有致病性。形态学测定,可将其鉴定为A.alternata和A.tenuissima两类;基于组蛋白3基因序列分析,前一类与A.alternata(AF404620、KF997067和KR866858)相似性达99%,后一类与A.tenuissima(KT384348)相似性达99%以上。【结论】2016年引起石河子地区棉花苗期叶斑病的病原菌为A.alternata和A.tenuissima。

【Objective】The aim of the study is to verify the pathogens that cause cotton seedling leaf spot in Shihezi area.【Method】120samples of cotton leaf spot were collected from Shihezi area,and105strains of Alternaria spp were isolated and purified by conventional method,and15representative strains were identified through survey of morphological characteristics,test of pathogenicity and sequence analysis of histone3gene.【Result】The selected15representative strains were pathogenic.The pathogens were preliminarily identified as A.alternata and A.tenuissima according to morphological characteristics,respectively.Based on histone3gene sequence analysis,the results showed that the similarity of nucleotide homogeneity of A.alternata(AF404620,KF997067and KR866858)was99%and A.tenuissima(KT384348)was more than99%,respectively.【Conclusion】The pathogens causing cotton seedling leaf spot are A.alternata and A.tenuissima in Shihezi in2016.