摘要
青花菜褐茎病是近年来浙江省青花菜产区发生的一种新病害。对全省青花菜褐茎病的症状进行调查研究,对典型症状样本的病原菌进行了分离培养、镜检,发现青花菜褐茎病的病原菌不可分离培养,为专性寄生菌;病样镜检后发现病原菌孢囊梗呈二叉状分枝,小枝末端尖细,孢子囊椭圆形或卵形,大小为（24~27）μm×（15~20）μm,卵孢子球形,黄褐色,厚壁,直径30~40μm;用青花菜的褐色发病组织对健康青花菜花球和植株进行人工接种能引起与田间青花菜褐茎病相同的症状;PCR扩增该病原菌的rDNA ITS序列并进行序列比对分析,发现该菌与寄生霜霉Hyaloperonospora parasitica相似度达95%以上,结合组织培养获得的病原形态特征,明确青花菜褐茎病病原为寄生霜霉（H.parasitica）。
Broccoli brown stem,a new disease,was widespread in Zhejiang Province in recent years.To understand and control the disease,lots of model symptom samples were collected to separate and culture.The results indicated that the pathogen,as an obligate parasite,depended on the host plants and could not be cultured in vitro.In microscope,the sporangiophores of pathogen tapered on the tips with a shape like letter ＂Y＂,the sporangiums of which were oval or eggs,（24-27） μm×（15-20） μm,then the oospores with thick wall were roundness with snuff color.When inoculated some mycelium from sick tissues on the surface,the symptoms same as in fields appeared on healthy broccoli leaves and stems.On the other hand,rDNA ITS（Internal Transcribed Spacers） of pathogens were cloned and sequenced,and its similarity to Hyaloperonospora parasitica was more than 95%.Combining the molecular results with the morphological characters,it can be definitely certain that broccoli brown stem was caused by Hyaloperonospora parasitic.
出处
《浙江农业学报》
CSCD
北大核心
2010年第5期660-665,共6页
Acta Agriculturae Zhejiangensis
基金
浙江省重大科技攻关项目(2004C12001)
浙江省三农五方项目
关键词
青花菜
褐茎病
寄生霜霉
Brassica oleracea
brown stem disease
Hyaloperonospora parasitica
