Dhandaydham Murali, Charles Lauren, Zhu Hongyan, Starr James L, Huguet Thierry, Cook Douglas R, Prosperi Jean-Marie, Opperman Charles
Center for the Biology of Nematode Parasitism, NC State University, Campus Box 7253, Raleigh, NC 27695-7253 Department of Plant Pathology, 348 Hutchinson Hall, One Shields Avenue, University of California, Davis, CA 95616-8680 Department of Plant Pathology and Microbiology, 118 B L.F. Peterson Hall, Texas A & M University, College Station, TX 77843 CNRS-INRA BP 27 UMR215, 31326 Castanet Tolosan Cedex, France INRA-SGAP, Montpellier, Domaine de Melgueil, 34130, Mauguio, France.
J Nematol. 2008 Mar;40(1):46-54.
Root knot (Meloidogyne spp.) and cyst (Heterodera and Globodera spp.) nematodes infect all important crop species, and the annual economic loss due to these pathogens exceeds $90 billion. We screened the worldwide accession collection with the root-knot nematodes Meloidogyne incognita, M. arenaria and M. hapla, soybean cyst nematode (SCN-Heterodera glycines), sugar beet cyst nematode (SBCN-Heterodera schachtii) and clover cyst nematode (CLCN-Heterodera trifolii), revealing resistant and susceptible accessions. In the over 100 accessions evaluated, we observed a range of responses to the root-knot nematode species, and a non-host response was observed for SCN and SBCN infection. However, variation was observed with respect to infection by CLCN. While many cultivars including Jemalong A17 were resistant to H. trifolii, cultivar Paraggio was highly susceptible. Identification of M. truncatula as a host for root-knot nematodes and H. trifolii and the differential host response to both RKN and CLCN provide the opportunity to genetically and molecularly characterize genes involved in plant-nematode interaction. Accession DZA045, obtained from an Algerian population, was resistant to all three root-knot nematode species and was used for further studies. The mechanism of resistance in DZA045 appears different from Mi-mediated root-knot nematode resistance in tomato. Temporal analysis of nematode infection showed that there is no difference in nematode penetration between the resistant and susceptible accessions, and no hypersensitive response was observed in the resistant accession even several days after infection. However, less than 5% of the nematode population completed the life cycle as females in the resistant accession. The remainder emigrated from the roots, developed as males, or died inside the roots as undeveloped larvae. Genetic analyses carried out by crossing DZA045 with a susceptible French accession, F83005, suggest that one gene controls resistance in DZA045.
根结线虫（南方根结线虫属）和孢囊线虫（异皮线虫属和球孢囊线虫属）会感染所有重要的作物品种，这些病原体每年造成的经济损失超过900亿美元。我们用南方根结线虫、花生根结线虫和北方根结线虫、大豆孢囊线虫（SCN - 大豆异皮线虫）、甜菜孢囊线虫（SBCN - 甜菜异皮线虫）和三叶草孢囊线虫（CLCN - 三叶草异皮线虫）对全球种质资源库进行了筛选，鉴定出了抗性和感性种质。在评估的100多个种质中，我们观察到了对根结线虫不同的反应，对于大豆孢囊线虫和甜菜孢囊线虫感染则观察到非寄主反应。然而，对于三叶草孢囊线虫感染观察到了变异。虽然包括杰马隆A17在内的许多品种对三叶草异皮线虫具有抗性，但帕拉吉奥品种高度感病。确定蒺藜苜蓿是根结线虫和三叶草异皮线虫的寄主以及对根结线虫和三叶草孢囊线虫不同的寄主反应，为从基因和分子层面表征参与植物与线虫相互作用的基因提供了机会。从阿尔及利亚群体获得的种质DZA045对所有三种根结线虫都具有抗性，并用于进一步研究。DZA045的抗性机制似乎与番茄中Mi介导的根结线虫抗性不同。线虫感染的时间分析表明，抗性和感性种质在线虫侵入方面没有差异，即使在感染几天后，抗性种质中也未观察到过敏反应。然而，在抗性种质中，不到5%的线虫群体以雌虫形式完成生命周期。其余的线虫从根部迁出，发育为雄虫，或在根部内作为未发育的幼虫死亡。通过将DZA045与感性的法国种质F83005杂交进行的遗传分析表明，一个基因控制DZA045中的抗性。
