进境鸡爪槭中日本短体线虫的鉴定

Identification of Pratylenchus japonicus intercepted in Acer palmatum from Japan

2013年2月从宁波口岸进境的日本鸡爪槭（Acer palmatum）树木根际介质中检测到1种短体线虫,由于短体属线虫具有很大的危害性,可对多种作物造成危害引起根腐病,因此对该种线虫进行了详细的形态特征描述和分子生物学特征分析,旨在为中国口岸植物检疫提供理论依据。采用形态学特征鉴定的方法将该线虫群体初步鉴定为日本短体线虫（Pratylenchus japonicus Ryss,1988）,其主要形态鉴别特征为：唇区有3个浅环,第1个唇环前端凸出;口针长而粗壮;阴门位置靠后,V值为84.0~88.7;受精囊内无精子;后阴子宫囊短,长度为12.4~21.5μm;尾细长,末端光滑。结合核糖体DNA的ITSRFLP图谱特征以及ITS区及28S-D2/D3区序列构建的系统发育树分析,进一步证实了该群体为日本短体线虫。结论：日本短体线虫是中国进境植物检疫性线虫,目前国内尚无分布的报道,这是中国口岸首次截获。

A Pratylenchus population was intercepted at Ningbo Port,China and isolated from root system of Acer palmatum imported from Japan in February of 2013.The root lesion nematodes can cause serious damage to root systems and play important role in international trade and are ranked as the plant quarantine pests in China.So in this paper,the detailed morphological description and the analysis of molecular biological characteristics for the Pratylenchus sp.were carried out in order to provide technical support for Chinese plant quarantine services.In this study,the morphological and molecular identifications were carried out for the intercepted population.Based on the morphological characters and molecular identification,the Japanese population was identified as Pratylenchus japonicus Ryss,1988.The morphological characters of the population were mainly as follows： labial region with three shallow annuli,the first lip annule with distinctly convex anterior margin; stylet long and stout; vulva posterior with V value of 84.0-88.7; spermatheca empty without sperms; post-vulva uterine branch short with length of 12.4-21.5 μm; tail slender with smooth tail terminus.The size of PCR products of ITS was 850 bp,the sizes were 380 bp,380 bp and 80 bp after AluⅠ endonuclease digestion,the sizes were 400 bp,350 bp and 110 bp after HhaⅠ endonuclease digestion,the sizes were 400 bp,180 bp,150 bp and 130 bp after HinfⅠ endonuclease digestion,the sizes were 500 bp and 350 bp after Hae Ⅲ endonuclease digestion.The phylogeny based on sequences of ITS and 28SD2 / D3 region revealed the intercepted population was a independent Pratylenchus sp.The characters of ITS-RFLP patterns of ribosomal DNA and the phylogenetic analyses based on sequences of ITS and 28S-D2 /D3 region further supported the morphological identification.Pratylenchus japonicus was listed as the imported plant quarantine pest in China and up-to-date no distribution was reported.This is the first report for the interception in China.