水稻根结线虫病的病原鉴定及其侵染源的研究

Pathogen Identification and Infection Sources of Rice Root-Knot Disease

在福建省政和县稻田发现大面积的严重水稻根结线虫病,沟渠内禾本科杂草油芒(Eccoilopus sp.)也遭受根结线虫(Meloidogyne sp.)的严重侵染。这两种寄主的根结线虫形态特征与拟禾本科根结线虫(Meloidogyne graminicola,Goldenand Birchfield,1965)原始描述相符;对根结线虫的rDNA-ITS区、28SrDNA-D2/D3区进行了扩增、克隆与测序,其序列与GenBank中拟禾本科根结线虫的相似性达99%以上,据此将水稻和油芒上的根结线虫鉴定为拟禾本科根结线虫。通过交叉接种试验和田间调查,证实油芒是水稻根结线虫的重要寄主,为田间水稻根结线虫病的重要侵染源。

The severe occurrence of rice root-knot disease on a large scale was found in Zhenghe,Fujian Province,China.Severe root-knot nematode infestation was also found on grass Eccoilopus sp.of Gramineae in drainage ditch adjacent to rice fields.Morphological characteristics and measurements of root knot nematode on rice or on Eccoilopus sp.were consistent with the original description of Meloidogyne graminicola.The regions of rDNA-ITS and 28S rDNA-D2/D3 of the root knot nematodes were amplified,cloned and sequenced.The sequence each of region had a high degree of genetic similarity（99%） to the relevant regional sequences of M.graminicola in GenBank.The results showed that the species of root-knot nematodes on rice or Eccoilopus sp.was M.graminicola.The results of habitat investigation and inoculation experiments showed that Eccoilopus sp.was an important host of M.graminicola,and served as an important source of infection of rice root-knot nematode disease in fields.