金橘脚腐病病原菌鉴定

Identification of the pathogen causing foot rot of Fortunella margarita(Lour.) Swingle

金橘[Fortunella margarita(Lour.) Swingle]为芸香科(Rutaceae)柑橘亚科(Aurantioideae)金柑属(Fortunella)多年生常绿木本植物,原产于我国,全国各柑橘产区均有栽培。广西桂林阳朔地区盛产金橘,随着金橘树栽培面积的扩大,病害逐渐加重。其中,尤以金橘脚腐病最为突出。金橘脚腐病主要发生在近地面的根茎部,表现为皮层组织腐烂、流胶;轻者植株生长衰退、果小、产量降低、品质变劣,重者全株枯死。

Foot rot of kumquat [Fortunella margarita（Lour.） Swingle] is a big problem in Guilin,Guangxi Zhuang Autonomous Region,where kumquat is one of the main cash crops.The affected trees decline gradually and finally wilt as the lesion girding the trunk.The suspected pathogen isolates of Phytophthora citrophthora,which identified by morphology,were always obtained from affected trunks.The pathogenicity of those isolates were confirmed by inoculating the representative isolate GLC15 on kumquat seedlings,shoots and branches.The identification was further confirmed by alignment the sequences of internal transcribed spacer（ITS） and translation elongation factor 1 alpha gene（TEF-1α）,amplified by PCR.The sequences were deposited in GenBank with accession numbers GU133068（ITS） and HQ637486（TEF-1α）,while the pathogen culture was deposited in Institute of Biotechnology,Zhejiang University.