凤仙白粉病的病原菌鉴定

Identification of the Pathogen Causing Rose Balsam Powdery Mildew

凤仙白粉病菌使凤仙花科植物叶片出现白色病斑.对河南商丘地区的凤仙白粉病菌进行了致病性分析、形态学及分子生物学鉴定.该病原菌分生孢子椭圆形或桶形,大小为22～28μm×16～21μm.分生孢子梗直立,圆柱形,简单不分枝,包含1个足细胞,1～3个远基细胞,3～6个排列成链的桶形分生孢子,大小为112～180μm×9～12μm.对该病原菌rDNA ITS进行PCR扩增和序列测定,GenBank登记号为FJ625796,并对该序列和GenBank中凤仙白粉菌Podosphaera balsaminae的ITS序列做了近邻归群法分析.结果证明,河南商丘地区的凤仙白粉病菌为Podosphaera balsaminae,这将为研究中国凤仙白粉病菌系统进化及凤仙白粉病的防治奠定基础.

Podosphaera balsaminae has been recorded in China,which causing powdery mildew on Impatiens balsamina(rose balsam).The powdery mildew is found in Shangqiu field in Henan,it is tested basing on the etiological,morphological and molecular characteristics.Conidia are ellipsoid or doliform,22～28 μm×16～21 μm,conidiophores are observed unbranched,cylindrical,112～180 μm×9～12 μm,containing a foot cell,1-3 distal cells and three to six barrel-shaped conidia formed in chain.The internal transcribed spacer(ITS) sequence is determined by PCR product amplifying and sequencing,this nucleotide sequence is assigned GenBank accession No FJ625796,and The N-J phylogenetic analysis of this ITS sequence with other ITS sequences of Podosphaera balsaminae from GenBank is made.The results show that the pathogen of rose balsam powdery mildew in Shangqiu is Podosphaera balsaminae.This result will lay a foundation for the phylogeny analysis and disease prevention of rose balsam powdery mildew in China.