鸢尾丝囊霉(Aphanomyces iridis)引起的烟草漂浮苗根腐病的初步报道

摘要

To ascertain root rot pathogen, 12 samples were collected from Baofeng, Biyang, Xuchang, Linying of Henan province in May 2017, and were analyzed by pathogenicity test. Morphological characteristics were identifi ed and 18S rDNA-ITS sequence analysis was conducted. A total of 10 fungal isolates were obtained from these samples, and their 18S rDNA-ITS sequences were 99% homologous to Aphanomyces iridis sequence in the NCBI database.Inoculation experiment of floating and potted plants showed that the incidence was 100%, and the same pathogen was also separated from diseased tissue on PDA medium. According to symptom and pathogen, the disease was identified as tobacco seedling root rot in floating bed which was caused by Aphanomyces iridis.This is the first time that Aphanomyces proved to have caused tobacco seedling root rot.%为明确近年来烟草漂浮育苗过程中出现的疑似根腐病的病原,2017年5月分别从河南省宝丰、泌阳、许昌、临颍等烟区苗床共采集12个具有代表性的病害样本,进行病原菌分离、形态学鉴定、18S rDNA-ITS序列分析和致病性测定.结果表明,从样本中分离纯化出10个真菌菌株,其18S rDNA-ITS序列与NCBI数据库中鸢尾丝囊霉(Aphanomyces iridis)序列同源性均为99%.漂浮苗及盆栽接种试验结果表明,烟苗接种后均有不同程度的发病,发病率为100%.将发病组织在PDA培养基上进行分离培养,也同样得到丝囊霉菌.本研究根据发病症状和病原菌,首次明确了鸢尾丝囊霉可引起烟草漂浮苗根腐病.