陈晶伟，马居奎，张成玲，杨冬静，唐伟，谢逸萍，孙厚俊

摘要：從江苏省徐淮地区7个采集地的甘薯块根中分离到7个甘薯茎线虫群体，通过形态学鉴定，其特征与已报道的腐烂茎线虫（Ditylenchus destructor）基本一致。利用rDNA-内转录间隔区（ITS）通用引物、腐烂茎线虫特异性引物检测，发现群体JSXZ为B（L）型，其余6个分离群体均为A（S）型腐烂茎线虫。结合ITS-5.8S-ITS2区序列分析并构建系统发育树，结果进一步表明，所获序列与腐烂茎线虫相似性最高，且各分离群体与徐淮地区已报道的相同基因型的腐烂茎线虫群体序列相似性均在99%以上。群体JSXZ没有与腐烂茎线虫A型、B型群体聚在一起，而是与C型、D型群体聚为1个分支，且和C型亲缘关系更近，所以群体JSXZ被鉴定为C型腐烂茎线虫;群体JSWJ、JSYJ、JSGS、JSHW、JSLQ和JSNG与A型腐烂茎线虫群体聚为1个分支，均为A型腐烂茎线虫，且与其他基因型区分明显。危害徐淮地区甘薯的腐烂茎线虫亲缘关系近，基因型种类多，存在A型、B型和C型，其中A型腐烂茎线虫为优势群体。

关键词：甘薯;腐烂茎线虫;鉴定;系统发育树

中图分类号：S432.4+5文献标识码：A文章编号：1000-4440（2021）06-1409-08

Morphological and molecular biology identification of seven stem nematode populations of sweet potato in Xuhuai area

CHEN Jing-wei，MA Ju-kui，ZHANG Cheng-ling，YANG Dong-jing，TANG Wei，XIE Yi-ping，SUN Hou-jun

（Xuzhou Institute of Agricultural Sciences in Xuhuai Area of Jiangsu/Key Laboratory of Biology and Genetic Improvement of Sweet Potato of Ministry of Agriculture and Rural Affairs， Xuzhou 221131， China）

Abstract：Seven populations of sweet potato stem nematodes were isolated from storage roots of sweet potatoes from seven regions in Xuhuai area of Jiangsu province. Characteristics of the stem nematodes were basically identical to Ditylenchus destructor reported previously through morphological identification. By detections using universal primers of rDNA- internal transcribed spacer （ITS） region and specific primers of D. destructor， it was found that population JSXZ belonged to B（L） type of D. destructor， while the other six isolated populations all belonged to A（S） type of D. destructor. The results further suggested that， the sequences of the stem nematodes shared the highest similarity with D. destructor though sequences analysis of ITS-5.8S-ITS2 region and phylogenetic tree construction， and sequence similarity of the separated populations compared with the D. destructor populations carrying the same genotype reported in Xuhuai area were all above 99%. Results of phylogenetic tree analysis showed that population JSXZ did not cluster into one branch with type A and type B populations of D. destructor， but clustered into one branch with type C and type D populations of D. destructor， and had closer affinity with type C. Therefore， JSXZ population from the sweet potato was confirmed as type C of D. destructor. Populations of JSWJ， JSYJ， JSGS， JSHW， JSLQ and JSNG were clustered into one branch with population of type A of D. destructor， which were all confirmed as type A of D. destructor and were clearly distinguished from other genotypes. It was indicated that populations of D. destructor which harmed sweet potatoes in Xuhuai area were closely related and had various genotypes， such as type A， type B and type C， among which type A was the dominant population.

Key words：sweet potato;Ditylenchus destructor;identification;phylogenetic tree

茎线虫病害严重威胁中国甘薯产业的发展，其病原物为腐烂茎线虫（Ditylenchus destructor），最早在马铃薯（Solanum tuberosum）上被发现，故也称Potato nematode[1]。国内腐烂茎线虫首先发现于甘薯（Ipomoea batatas）中，主要侵染贮藏根并引起腐烂，造成糠心或糠皮等症状，危害严重时可导致减产80%以上，乃至绝收[2-3]。随后，又在马铃薯及一些中药材上发现其危害[4-5]。现已被亚太植物保护组织及许多国家和地区列为植物检疫性有害生物[6]。……