河北廊坊大豆枯萎病病原镰刀菌的分子鉴定

Molecular identification of Fusarium species from the wilt soybean lines in Langfang,Hebei province

为明确河北廊坊中国农科院植保所试验基地大豆孢囊线虫病田内大豆枯萎病病原镰刀菌的种类,对362份罹病枯萎大豆植株进行病原真菌分离,得到335株真菌;使用镰刀菌通用引物鉴定出镰刀菌(Fusarium spp.) 279株,占分离菌株83.3%;镰刀菌特异性引物、测序等分子生物学技术结合形态学特征进一步鉴定镰刀菌种类,鉴定出尖孢镰刀菌(F. oxysporum) 189株,占分离菌株56.4%;茄病镰刀菌(F. solani) 67株占20.0%、禾谷镰刀菌(F. graminearum) 16株占4.8%、木贼镰刀菌(F. equiseti) 3株、层出镰刀菌(F. proliferaum) 2株、燕麦镰刀菌(F. avenaceum)和厚孢镰刀菌(F. chlamydosporum)各1株;致病性测试结果表明数量最多的尖孢镰刀菌(F. oxysporum)中约92.8%菌株具有不同程度的致病力;这些结果表明该试验基地大豆枯萎病的优势病原菌为尖孢镰刀菌(F. oxysporum);研究结果可为大豆枯萎病的防治提供科学依据,并为大豆孢囊线虫与尖孢镰刀菌复合侵染大豆的研究奠定基础。

In order to identify the Fusariumspp.within the wiltedsoybean lines at the agricultural station of Insti- "tute of Plant Protection,Chinese Academy of Agricultural Sciences in Langfang,Hebei province,which has a high density of soybean cyst nematode Heterodera glycines in the soybean field,335fungal strains were obtained from 362wilt soybean lines.279strains were screened by PCR using the Fusarium-universai primer pairs F1and F2,which accounted for 83.3%of all the strains.Combining the molecular techniques including Fusarium spe- cies-specific primers and sequencing and morphology of the colony and conidia,189F.oxysporum strains were identified with the highest percentage at 56.4%,while 67F.solani strains were isolated with the second highest percentage at 20.0%.Sixteen F.graminearum strains were obtained with a percentage at 4.8%.Another four Fu- sarium species including F.equiseti,F.proliferaum,F.avenaceum and F.chlamydosporum were also identified at low frequency with 3,2,1and 1strains,respectively.Pathogenicity assay showed that about 92.8%F.oxys- porum strains had differential virulence.Theresults of this study showed that F.oxysporum was the predominant pathogen in the soybean field.Our findings not only provide scientific evidence for the control of soybean wilt disease,but also lay a foundation for the studies of the disease complex caused by H.glycines and F.oxysporum.