山东省小麦根腐病病原菌的分离鉴定

Isolation and identification of the pathogens causing wheat common root rot in Shandong Province

为明确山东省小麦根腐病的病原菌种类,于2012—2014年从山东省10个地市采集小麦病株,通过组织分离法获得了185株分离物,利用形态学鉴定方法,结合基于5.8S r DNA-ITS序列或TEF-1α基因序列分析的分子鉴定方法对分离物进行了鉴定。结果表明:分离物中共得到135株麦根腐平脐蠕孢Bipolaris sorokiniana,占分离病原菌总数的72.97%,属优势种群;50株镰孢属Fusarium菌株,其中14株尖孢镰孢菌Fusarium oxysporum、19株层出镰孢菌Fusarium proliferatum和17株黄色镰孢菌Fusarium culmorum;按照柯赫氏法则进行致病性测定,证实了4种病原菌对鲁麦21号具有致病性,麦根腐平脐蠕孢的致病力较强,病情指数显著高于镰孢菌属真菌。研究表明,山东小麦根腐病主要是由麦根腐平脐蠕孢和镰孢属真菌侵染引起的,麦根腐平脐蠕孢为优势菌群。

To identify the pathogen causing wheat root rot,a total of 185 isolates from rot lesions of wheat roots collected from ten cities in Shandong Province during 2012—2014 were identified by using morphological method and molecular method based on 5.8S r DNA-ITS or TEF-1α sequences.The results showed that Bipolaris sorokiniana was the main pathogen（72.97%） of wheat common root rot,with 135 isolates identified,and the other fungi were Fusarium oxysporum（14 isolates）,F.proliferatum（19isolates） and F.culmorum（17 isolates）.The pathogenicity test according to Koch＇s postulates showed that there were four pathogens in wheat cultivar Lumai 21,while B.sorokiniana showed significant higher pathogenicity and disease index than Fusarium sp.strains.The pathogens causing wheat root rot in Shandong Province were B.sorokiniana and Fusarium sp.,and B.sorokiniana was the dominant species.