赵伟超 秦朝 张江利 李明军 杨清香 高锦

摘要 为明确河南省温县铁棍山药病原线虫种类，在温县铁棍山药种植区采集有明显症状的块茎进行线虫分离，观察线虫的雌、雄成虫的形态特征，并扩增rDNA的 28S D2-D3序列对其进行分子生物学鉴定。结果表明，从山药块茎中分离出的根腐线虫形态学特征及测量指标与咖啡短体线虫Pratylenchuscoffeae基本一致，其28S D2-D3序列与P.coffeae相似性达99.87%～100%。本研究明确了河南省温县地区铁棍山药根腐线虫为咖啡短體线虫，为山药线虫病的鉴别及防控提供了科学依据。

关键词 咖啡短体线虫;铁棍山药;病原;鉴定

中图分类号： S435.39

文献标识码： A

DOI： 10.16688/j.zwbh.2021487

Abstract In order to clarify the nematode pathogen species of Dioscorea polystachya root lesion nematode rot disease in Wenxian of Henan province， the tubers with obvious symptoms were collected for isolating nematodes from the planting region of yam in November， 2020. The pathogenic nematodes were identified by observing the traditional morphological characteristics of female and male adults， and molecular biological identification was carried out based on 28S D2-D3 sequence of rDNA. The results showed that the morphological characteristics and measurement indexes of root lesion nematodes isolated from yam tubers were consistent with those of Pratylenchus coffeae， and the 28S D2-D3 sequence was 99.87%-100% identical to that of P.coffeae. This study confirmed for the first time that the root lesion nematode of D.polystachya in Wenxian of Henan province was P.coffeae， and provided a scientific basis for the identification and control of yam nematode diseases.

Key words Pratylenchus coffeae;Dioscorea polystachya;pathogen;identification

铁棍山药Dioscorea polystachya ‘Tiegun原产于河南怀区（温县、沁阳、武陟等地），是山药中的优良品种[1-2]，在河南、河北、山东等山药主产区广泛种植，是我国种植面积最大的山药品种。铁棍山药地下块茎的营养成分和药用成分含量很高，品质极佳，深受广大消费者青睐[3]，市场前景广阔。

目前，我国发现的危害山药的线虫主要分为两个属，分别是根结线虫属Meloidogyne和短体线虫属Pratylenchus[4]。根结线虫主要危害山药的根系和块茎，受害植株前期地上部分无明显症状;中后期叶片变小，严重时叶片变黄脱落。在线虫侵入点周围凸起，产生如米粒大小的根结，严重时多个根结愈合形成疙瘩，块茎生长点受到损伤，影响其膨大及发育。短体线虫也被称为根腐线虫（root-rot nematode），初期危害山药的种薯和幼根，在侵染点附近可形成小的枯斑，严重时联合形成黑色复合病斑，导致根系死亡;后期主要危害山药块茎，先形成浅褐色小点，随后转变为近圆形或不规则形的褐色病斑，受害的块茎病斑形成大片黑褐色斑块，引起山药块茎的腐烂，严重影响山药的产量与品质。……