Smiley Richard W, Whittaker Ruth G, Gourlie Jennifer A, Easley Sandra A
Professor.
Faculty Research Assistants, Oregon State University, Columbia Basin Agricultural Research Center, P.O. Box 370, Pendleton 97801.
Plant Dis. 2005 Sep;89(9):958-968. doi: 10.1094/PD-89-0958.
Many wheat (Triticum aestivum) fields planted annually in the Pacific Northwest are infested by high populations of the lesion nematode, Pratylenchus neglectus. Spring wheat cultivars varying in tolerance and resistance to P. neglectus were treated or not treated with aldicarb to examine relationships between the nematode and growth and yield of annual direct-seeded (no-till) wheat. Increasing initial density of P. neglectus in soil was more strongly associated with declining growth and yield of intolerant (Machete and Spear) than moderately tolerant (Frame and Krichauff) cultivars. Yield suppression by P. neglectus was generally 8 to 36% for intolerant cultivars, but reached 71% in soil also harboring Heterodera avenae, Rhizoctonia solani AG-8, and Gaeumannomyces graminis var. tritici. Intolerant cultivars had lower yields than Krichauff in rainfed but not in irrigated experiments. Density of P. neglectus in mature roots was generally lower for moderately resistant Krichauff than for susceptible Machete and Spear. Aldicarb improved yields in irrigated but not in rainfed experiments, and increased plant height and reduced variability in tiller height, canopy temperature, and density of P. neglectus in roots. This is the first report of damage to wheat by P. neglectus in the Pacific Northwest. Breeding wheat for tolerance and resistance to P. neglectus is suggested.
太平洋西北地区每年种植的许多小麦（普通小麦）田都受到大量伤残线虫（Pratylenchus neglectus）的侵害。对耐P. neglectus能力和抗性不同的春小麦品种进行或不进行涕灭威处理，以研究线虫与一年生免耕小麦生长和产量之间的关系。土壤中P. neglectus初始密度的增加与不耐受品种（Machete和Spear）生长和产量下降的关联比中度耐受品种（Frame和Krichauff）更强。对于不耐受品种，P. neglectus造成的产量抑制一般为8%至36%，但在同时含有燕麦孢囊线虫、立枯丝核菌AG-8和小麦全蚀病菌的土壤中，产量抑制率达到71%。在雨养试验中，不耐受品种的产量低于Krichauff，但在灌溉试验中并非如此。对于中度抗性的Krichauff，成熟根中P. neglectus的密度通常低于感病品种Machete和Spear。涕灭威在灌溉试验中提高了产量，但在雨养试验中没有，并且增加了株高，降低了分蘖高度、冠层温度和根中P. neglectus密度的变异性。这是太平洋西北地区P. neglectus对小麦造成损害的首次报道。建议培育耐P. neglectus和抗P. neglectus的小麦品种。
