Identification of the Pathogenic Fungus Causing Tobacco Leaf Spot Disease in Hengyang Region
[Objective]To clarify the unknown leaf spot pathogen of a newly discovered tobacco leaf disease in Hengyang and its biological characteristics.[Method]Koch's postulates,the isolation,purifica-tion,morphological observation,ITS,EF-1α,β-tubulin and RPB2 sequence analysis,construction of phylogenetic tree,as well as pathogenicity determination were employed for the identification and analysis of the diseased leaves.[Result]After observation,the aerial mycelia edge was neat,presenting a deep gray color on the front and a dark brown color on the back.The conidial spores were oval-shaped[(1.76～2.38)μm×(0.85～1.40)μm(n=50)].The ycSQ1 strain showed 99%-100%sequence identity with the sequences of ITS region,EF-1α,β-tubulin,and RPB2of Epicoccum sorghinum(GenBank ac-cession numbers MT341779.1,MF987524.1,OP555979.1,and MW899504.1).Subsequently,a phy-logenetic tree based on the ITS and β-tubulin sequences was constructed.ycSQ1 and Epicoccum sorghinum exhibited a close relationship(GenBank accession numbers MK391054.1 and MK391058.1),with a bootstrap value of 88%.Therefore,through morphological observation,molecular biology identifica-tion,and pathogenicity determination,it was confirmed that the pathogen causing the leaf spot disease in the tobacco production area of Hengyang was Epicoccum sorghinum.[Conclusion]This study marks the first discovery of Epicoccum sorghinum as the pathogen causing tobacco leaf spot disease in Hengyang Re-gion.This discovery holds significant importance in effectively controlling this disease and reducing the major economic losses it caused to tobacco production.
Tobaccoleaf spot diseaseEpicoccum sorghinumIsolation and identification
万方数据
维普
