范亚磊　赵敏　邓晟　刘瑞显　姚焕钊　魏利辉　冯辉

摘要： 根結线虫病长期以来对猕猴桃安全生产造成了严重威胁。调查发现江苏省连云港市部分猕猴桃种植园根结线虫病发生普遍，组织切片可见根部出现根结线虫诱导的特异的巨细胞。形态学观察和分子检测结果显示，尽管与其他群体存在一定差异，但仍确定本次分离自猕猴桃的根结线虫（种群编号：CN43）为北方根结线虫（Meloidogyne hapla）。基于内转录间隔区（ITS）和COⅡ-16S序列构建的遗传进化树显示，CN43分离群体与已知的北方根结线虫位于同一进化分支，而与其他种类的根结线虫明显区分开来。以ITS序列构建的中接网络将34个北方根结线虫分离群体划分为10个单倍型，其中CN43属于最大的单倍型群组;然而，单倍型分析不能确定各分离群体在地理分布上的关联性。综上，本研究首次报道了北方根结线虫在中国猕猴桃上的侵染和发生，其分离群体的形态学描述和分子特征分析可为揭示猕猴桃根结线虫的种群多样性和种间变异提供参考。

关键词： 猕猴桃;根结线虫;北方根结线虫;内转录间隔区（ITS）;COⅡ;进化分析

中图分类号： S436.634 文献标识码： A 文章编号： 1000-4440（2021）01-0075-08

Morphological description and molecular characteristic analysis on Meloidogyne hapla which infect kiwifruit in Jiangsu province

FAN Ya-lei1，2， ZHAO Min1， DENG Sheng1， LIU Rui-xian3，YAO Huan-zhao4， WEI Li-hui1， FENG Hui1

（1.Institute of Plant Protection， Jiangsu Academy of Agricultural Sciences， Nanjing 210014，China;2.School of Horticulture and Plant Protection， Yangzhou University， Yangzhou 225009，China;3.Institute of Industrial Crops， Jiangsu Academy of Agricultural Sciences， Nanjing 210014，China;4.Plant Protection Station of Tongshan District of Xuzhou City， Xuzhou 221116，China）

Abstract： Root-knot diseases caused by Meloidogyne spp. have posed great threat to global kiwifruit industry for a long time. It was found through investigation that， the disease caused by root-knot nematode was common in part of the kiwifruit plantations in Lianyungang City， Jiangsu province. The specific giant cells were found in tissue slices of roots， which may be induced by root-knot nematodes. Results of morphological observation and molecular detection indicated that， the root-knot nematode （population code： CN43） separated from kiwifruits was confirmed to be Meloidogyne hapla， although there was difference compared with other polulations. Phylogenetic trees inferred from internal transcribed spacer （ITS） and partial COⅡ-16S sequences revealed that， isolate population of CN43 and M. hapla were within the same clade and could be separated from other root-knot nematode species obviously. Isolates of 34 M. hapla in NCBI database were divided into ten haplotypes using median-joining network constructed by ITS sequence， in which CN43 belonged to the largest haplotype group. However， haplotype analysis could hardly show the correlation of geographic distribution between the isolates. In conclusion， infection and occurrence of M. hapla in kiwifruit trees of China was reported for the first time. Analysis on the morphology and molecular characteristics of the isolated M. hapla populations can provide reference for revealing population diversity and intraspecific variability of root-knot nematodes in kiwifruit.

Key words： kiwifruit;root-knot nematode;Meloidogyne hapla;internal transcribed spacer（ITS）;COⅡ;phylogenetic analysis

猕猴桃（Actinidia deliciosa）是起源于中国的适合在温热带地区栽培的重要果树，目前已在20多个国家得到种植，截至2011年，中国以外地区猕猴桃收获面积达到9.4×104 hm2[1]。然而，随着猕猴桃产业和规模的不断发展，猕猴桃根结线虫病害问题日益凸显。根结线虫（Meloidogyne spp.）在全世界各猕猴桃种植区广泛存在，其中南方根结线虫（M. incognita）和北方根结线虫（M. hapla）是主要病原线虫种类。……