国槐根茎腐烂病病原菌的形态与分子鉴定

Morphological and Molecular Identification of the Fusarium Pathogen Causing Root Rot Disease of Chinese Scholartree

为了确定引起国槐根茎腐烂病的病原菌种类,以国槐(Sophora japonica Linn.)典型根茎腐烂病病株为试材,采用组织分离法获得纯菌株,并对所得菌株进行致病性测定、形态学鉴定及rDNA-ITS序列分析,研究了国槐根茎腐烂病的病原菌种类。根据24个菌株的培养性状和形态特征,鉴定所分离菌株均为镰刀菌。致病性测定表明,24个菌株均能侵染寄主树皮组织使其腐烂变黑褐色。在Gen Bank序列数据库中,24个菌株的DNA序列分别与多隔镰刀菌(Fusarium decemcellulare)、层生镰刀菌(F.proliferatum)、木贼镰刀菌(F.equiseti)、F.keratoplasticum和腐皮镰刀菌(F.solani)的ITS序列同源性为99%~100%。

With Sophora japonica Linn. root rot, the pathogens were isolated by tissue separation, tested hy the standard Koch＇ s postulation methods, and identified by the methods of microscopy and molecules, and the pathogen species of Chinese scholartree root rot were studied. From the culture characters and morphological characteristics of the 24 strains, the isolated strains were identified as Fusarium sp. These strains of Fusarium could infect in vivo Chinese scholartree barkes and make it black brown and rot. In GenBank sequence database, the DNA sequence homology of 24 strains with F. decemcellulare, F. proliferatum, F. equiseti, F. keratoplasticum, and F. solani were 99%-100%, respectively.