Mitchum Melissa G, Wrather J Allen, Heinz Robert D, Shannon J Grover, Danekas Gene
Division of Plant Sciences and Bond Life Sciences Center, University of Missouri-Columbia, Columbia 65211.
Division of Plant Sciences, University of Missouri-Delta Center, Portageville 63873.
Plant Dis. 2007 Nov;91(11):1473-1476. doi: 10.1094/PDIS-91-11-1473.
The soybean cyst nematode, Heterodera glycines, is a serious economic threat to soybean producers in Missouri. Periodic monitoring for the presence, population densities, and virulence phenotypes of H. glycines is essential for determining crop losses and devising management strategies implementing the use of resistant cultivars. A survey using area-frame sampling was conducted to determine the distribution and virulence phenotypes of H. glycines in Missouri during 2005. Two samples from each of 125 fields representing eight geographical regions of Missouri were collected; 243 samples were processed for extraction of cysts and eggs. In all, 49% of samples had detectable cyst nematode populations, which ranged from 138 to 85,250 eggs per 250 cm of soil. Race and H. glycines type tests were conducted on populations from 45 samples. Nearly 80% of the populations that were tested, irrespective of the region, were virulent on the indicator line plant introduction (PI) 88788, which is the source of resistance for most H. glycines-resistant cultivars. More than 70% of populations could reproduce on the indicator lines PI 88788, PI 209332, and PI 548316 (Cloud), indicating that soybean cultivars with resistance derived from these sources need to be carefully monitored and used only in rotation with nonhost crops and soybean cultivars with resistance from other sources. Approximately one-third of the populations, primarily in the southern regions of Missouri, could reproduce on PI 548402 (Peking), another common source of resistance. Fewer than 10% of the populations could reproduce on PI 90763, PI 437654, PI 89772, or PI 438489B, suggesting that these sources of resistance should be used in soybean breeding programs to develop H. glycines-resistant soybean cultivars.
大豆胞囊线虫（Heterodera glycines）对密苏里州的大豆种植者构成了严重的经济威胁。定期监测大豆胞囊线虫的存在情况、种群密度和毒力表型对于确定作物损失以及制定实施抗性品种使用的管理策略至关重要。2005年，采用区域框架抽样法进行了一项调查，以确定密苏里州大豆胞囊线虫的分布和毒力表型。从代表密苏里州八个地理区域的125个田地中各采集了两个样本；对243个样本进行了处理，以提取胞囊和虫卵。总体而言，49%的样本检测到有胞囊线虫种群，每250厘米土壤中的虫卵数量在138至85250个之间。对45个样本中的种群进行了生理小种和大豆胞囊线虫类型测试。无论来自哪个区域，近80%接受测试的种群对指示品系植物引进（PI）88788具有毒性，而PI 88788是大多数抗大豆胞囊线虫品种的抗性来源。超过70%的种群能够在指示品系PI 88788、PI 209332和PI 548316（Cloud）上繁殖，这表明源自这些来源的抗性大豆品种需要仔细监测，并且仅与非寄主作物以及来自其他来源的抗性大豆品种轮作使用。大约三分之一的种群，主要在密苏里州南部地区，能够在PI 548402（北京）上繁殖，PI 548402是另一个常见的抗性来源。不到10%的种群能够在PI 90763、PI 437654、PI 89772或PI 438489B上繁殖，这表明这些抗性来源应在大豆育种计划中用于培育抗大豆胞囊线虫的大豆品种。
