五株大豆疫霉鉴定及其致病力差异机制初步研究

Identification of Five Strains of Phytophthora Sojae and Mechanism of Pathogenic Difference

本文从被侵染的大豆根茎及土壤中分离了5株病原真菌,在V8培养基上能较好的生长菌落呈现白色绒毛状松散.5株病原菌均能产生卵孢子和孢子囊,孢子囊低温诱导释放游动孢子,它们趋向性侵染大豆根部.利用特异性引物ITS6和ITS8扩增其保守序列区域,经测序比对与NCBI发布的大豆疫霉菌株序列同源性为100%;根据形态学和分子生物学结果鉴定为大豆疫霉.5株大豆疫霉的生长速率和致病力存在差异,其致病力与生长速率以及致病基因的表达成正相关关系.

Five strains of pathogenic fungus were isolated from the infected soybean rhizomes and their soil which could grow well on V8 medium,and the colonies were white,loose and fluffy.All of the five strains of pathogens produced oospores and sporangia,and their sporangia released zoospores under low temperature induction,which tended to infect soybean roots.Using specific primers ITS6 and ITS8 to amplify its conserved sequence region,and comparing it with the sequence of Phytophthora sojae strain released by NCBI after sequencing,and the homology was 100%;Therefore,according to the identification methods of morphology and molecular biology,they were identified as P.sojae.The growth rate and pathogenicity of these five strains of P.sojae are different,and their pathogenicity is positively correlated with the growth rate and the expression of pathogenic genes.