上海地区鲜食玉米穗腐病致病镰孢菌的分离与鉴定

为明确上海地区鲜食玉米穗腐病致病镰孢菌的组成和分布,2020年在上海地区各鲜食玉米种植区采集66份穗粒腐果穗病样,通过组织分离、单孢纯化,获得272株单孢分离物。采用形态学和分子生物学等方法对单孢分离物进行鉴定,共鉴定到8个镰孢种203株镰孢菌,其中拟轮枝镰孢、变红镰孢、亚洲镰孢、产黄色镰孢、木贼镰孢、层出镰孢、新知镰孢和居群镰孢的分离频率依次为67.98%、9.36%、6.90%、5.91%、5.42%、2.96%、0.99%和0.49%。在不同采样区拟轮枝镰孢菌占比存在差异,崇明、奉贤和青浦地区采集的样品中拟轮枝镰孢菌分别占76.25%,71.62%和48.98%。结果表明,拟轮枝镰孢在上海地区鲜食玉米种植区广泛分布,为上海地区鲜食玉米穗腐病的主要优势致病菌。

Isolation and Identification of Fusarium Species Causing Fresh Maize Ear Rot in Shanghai

To clarify the composition and distribution of the pathogenic Fusarium of fresh maize ear rot in Shanghai, 66 samples of ear rot were collected in fresh maize planting area in Shanghai in 2020. Through tissue isolation and single spore purification, 272 single spore isolates were obtained. These single spore isolates were further identified by morphology and molecular biology methods. Ultimately, 8 Fusarium including 203 Fusarium species were identified. These Fusarium isolates were Fusarium verticillioides, Fusarium incarnatum, Fusarium asiaticum, Fusarium thapsinum, Fusarium equiseti, Fusarium proliferatum, Fusarium andiyazi and Fusarium commune, the separation frequencies of which were 67.98%, 9.36%, 6.90%, 5.91%, 5.42%, 2.96%, 0.99% and 0.49% respectively. The proportion of F. verticillioides varies in different sampling regions. For the samples collected from Chongming, Fengxian, and Qingpu districts, F. verticillioides accounted for 76.25%, 71.62% and 48.98%, respectively. The results showed that F. verticillium, as the main dominant pathogen of fresh maize ear rot, is widely distributed in Shanghai.