西南部分地区荞麦根结线虫种类与地理分布

近年来,随着我国荞麦面积的迅速增加,根结线虫病呈逐年加重趋势,严重影响了荞麦的产量与品质。本研究于2014年对西南10个地区17个乡镇秋播苦荞麦根结线虫的分布、发生种类以及危害程度进行了调查。结果表明,西南地区危害荞麦的根结线虫种类有南方根结线虫(Meloidogyne incognita)、爪哇根结线虫(M.javanica)和花生根结线虫(M.arenaria)3种,其中南方根结线虫为优势种群。田间根结线虫种群大多数为单一种群,23.5%的样品为南方根结线虫与爪哇根结线虫(或花生根结线虫)组成的混合种群。调查发现前作为烟草或马铃薯的地块,荞麦根结线虫发生危害严重,平均被害株率为6.0%~77.5%,病情指数为1.4~26.1,而前作为玉米的荞麦根结线虫则较轻,被害株率最高为16.0%,相应病情指数为2.3。

Geographical distribution and species of root-knot nematodes on buckwheat in some areas of southwest China

In recent years, root-knot nematode disease in China increased year by year and seriously affected the crop yield and quality as the rapidly extending of the buckwheat growing. During 2014, the distribution, species and damage of root-knot nematodes on buckwheat were investigated in southwest China. Three species, including Meloidogyne incognita, M. javanica and M. arenaria, were observed on buckwheat, and M. incognita was the dominant species. Most root-knot nematode populations are single species in fields, and only 23.5% samples were mixed populations of M. incognita and M. arenaria (or M. javanica). The root knot nematodes occurred seriously on buckwheat when preceding crop was tobacco or potato, and the average damage rate ranged from 6% to 77.5%, with the disease indexes varied between 1.4 and 26.1. However, the root knot nematodes only lightly occurred if corn was the preceding crop, and the highest damage rate was 16% with a disease index of 2.3.