甘肃淫羊藿叶斑病的病原鉴定与生物学特性OA

Leaf spots disease occurred in Epimedium brevicomu planting area of Weiyuan County,Dingxi City,Gansu Province,seriously affected the yield and quality of E.brevicomu.In order to explore the pathogenic species of E.brevicomu leaf spots,morphological characteristics combined with multi-gene(ITS,TUB2,ACT,GAPDH,CHS-1)molecular biology were conducted.The mycelial growth rate method was used to study biological characteristics.At the same time,controlled indoor inoculations on detached leaves from Leguminosae were performed to identify the potential hosts for pathogen infection.The results of Koch's postulates showed that 10 strains of fungi exhibited same morphological characteristics were etiological agents of E.brevicomu leaf spots.Based on morphological and multi-gene sequences analysis,the representative strain YYH-2 was identified as Colletotrichum incanum.The optimum temperature for strain growth was 25 to 28℃,the optimum pH was 8.0,the optimum carbon source and nitrogen source were soluble starch and beef extract,respectively,and light exposure was beneficial for mycelial growth.Under artificial inoculation conditions,the pathogen can infect the leaves of soybean(Glycine max),broad bean(Vicia faba)and cowpea(Vigna unguiculata).It was the first report of C.incanum as a novel anthracnose pathogen capable of infecting E.brevicornum and cause anthracnose under natural conditions.This study also identified V.faba and V.unguiculata as potential hosts of this pathogen,and highlighted C.incanum's low environmental requirements and robust adaptability.This study provides a theoretical guidance for the diagnosis and subsequent prevention and control of E.brevicomu leaf diseases.