甘肃省玉米根腐病致病镰孢菌分离与鉴定

为明确甘肃省玉米根腐病致病镰孢菌种类，2017～2019年在甘肃省不同地区采集玉米植株进行组织分离，采用形态学和分子生物学鉴定方法对分离物进行鉴定，按照柯赫氏法则对其致病性进行测定。结果表明，引起甘肃省玉米根腐病的致病镰孢菌为厚垣镰孢Fusarium chlamydosporum、禾谷镰孢F.graminearum、尖镰孢F.oxys-porum、层出镰孢F.proliferatum、茄镰孢F.solani、三线镰孢F.tricinctum、拟轮枝镰孢F.verticillioides和产黄色镰孢F.thapsinum，其中尖镰孢和拟轮枝镰孢为优势镰孢菌，分离频率分别为22.5%和20%。通过致病性测定发现，所有分离的镰孢菌都会引起玉米根系不同程度变褐，导致根系生长缓慢、茎基部溢缩和腐烂、近地部叶片黄化、叶边缘干枯等症状。

Isolation and Identification of Fusarium spp. from Maize Root Rot in Gansu Province

To identify the species of pathogenic Fusarium spp. maize root rot in Gansu province, maize plants were collected for tissue isolation in different areas of Gansu province from 2017 to 2019. The isolates were identified by morphological identification and molecular biology identification, and the pathogenicity was determined according to Koch''s rule. The results showed that F. chlamydosporum, F. graminearum, F. oxysporum, F. proliferatum, F. solani, F. tricinctum, F. verticillioides, F. thapsinum caused maize root rot. Among them, F. verticillioides and F. oxysporum were the dominant pathogenic bacterium, the separation frequencies were 20% and 22.5%. Through the virulence test, it was found that all Fusarium spp. could cause the varying degrees browning of maize root, and also causes roots to grow slowly, stem base overflow and rot, chlorosis of leaves near ground, leaf margins dry and other symptoms.