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摘 要 通过室内接种方法测定土壤中接种象耳豆根结线虫（Meloidogyne enterolobii）二龄幼虫不同初始密度（0、0.125、0.25、0.5、1、2、4、8和16条/cm3）对黄瓜生长的影响。研究结果表明，黄瓜受损程度与象耳豆根结线虫初始接种密度呈正相关，随着接种密度的增加，形成的根结指数不断提高，而黄瓜植株高度和苗鲜重相比对照均表现为下降，即发病程度逐渐加重。当土壤中象耳豆根结线虫二龄幼虫的初始接种密度为0.25条/cm3，即可对黄瓜的株高和植株鲜重产生显著危害，初始密度为8条/cm3处理，则可导致黄瓜植株死亡。该研究结果可为制定象耳豆根结线虫的防治指标提供理论依据。

关键词 象耳豆根结线虫 ；黄瓜 ；初始密度 ；病情指数

分类号 S432.45

Effect of Initial Population Density of Meloidogyne enterolobii

on Cucumber Growth in Greenhouse

LONG Haibo SUN Yanfang ZENG Fanyun BAI Cheng

（Environment and Plant Protection Institute /

Ministry of Agriculture Key Laboratory of Pests Comprehensive Governance for Tropical crops /

Hainan Key Laboratory for Monitoring and Control of Tropical Agricultural Pests /

Hainan Engineering Research Center for Biological Control of Tropical Crops Diseases and Insect Pests， CATAS， Haikou， Hainan 571101， China）

Abstract The effects of initial population levels of Meloidogyne enterolobii [0， 0.125， 0.25， 0.5， 1， 2， 4， 8 and 16 second stage juvenlies （J2） per cm3 of soil] on cucumber were investigated with pot planting in a greenhouse. The results showed that there is a positive relationship between the initial population density of the nematode and the extent of damage it cause to cucumber. Both shoot height and shoot fresh weights were decreased as increasing initial densities of the nematodes， but the disease index was increased. When the initial inculcation density of M. eneterolobii reached to 0.25 J2 per cm3 of soil， either cucumber shoot height or fresh weight was reduced significantly. Moreover， inoculation of cucumber with eight J2 of M. eneterolobii could lead to plant dead. These results provide a possibility to estimate the economic threshold， which is needed for evaluation efficacy of nematode control.

Keywords Meloidogyne enterolobii ； cucumber ； initial density ； disease index

黄瓜（Cucumis sativus L.）是我国广泛栽培种植的蔬菜作物，种植面积占蔬菜总面积的10%左右[1]。近年来，随着复种指数的提高以及大棚设施农业的发展，黄瓜根结线虫病害普遍发生且逐年加重，一般可能减产20%～30%，严重时达到50%以上，甚至绝产[2]。为害黄瓜的根结线虫病原种主要有南方根结线虫（M. incognita）、爪哇根结线虫（M. javanica）、花生根结线虫（M. arenaria）和象耳豆根结线虫（M. enteolobii）。其中，象耳豆根结线虫近几年在海南多个市县的冬季瓜果蔬菜基地广泛发生，为害严重，已成为制约黄瓜生产的重要因素之一[3-5]。

根结线虫通过侵染寄生作物根系，破坏寄主的正常生理代谢水平，并且攫取寄主细胞营养物质，导致作物生长矮小、缓慢、叶色异常，结果少，产量低，有时造成植株提早死亡。根结线虫对作物的危害程度取决于线虫种类和寄主，同时与土壤中线虫的初始数量和外部环境密切相关[6]。……