Colgrove A L, Smith G S, Wrather J A, Heinz R D, Niblack T L
Department of Plant Microbiology and Pathology, University of Missouri, Columbia 65211.
Plant Dis. 2002 Oct;86(10):1101-1108. doi: 10.1094/PDIS.2002.86.10.1101.
Soybean cultivars with different sources of resistance to Heterodera glycines were grown at three locations initially infested with races 2, 3, and 6 in order to investigate H. glycines race shift in field populations. Each spring and fall, soil samples were taken from each plot and race tests were conducted to evaluate effects of cultivar and time of sampling. Field experiments were paired field plots rotated annually with corn since 1991. Cultivars included at the northern and central Missouri sites were Williams 82 (susceptible to H. glycines), Linford (PI 88788 source of resistance), MFA 9043 (Peking) replaced by Morsoy 9345 (Peking and PI 88788) from 1995 to 1997, and Jackson II (Peking + PI 88788) replaced by Asgrow 3431 (Peking and PI 88788) in 1996-97. Cultivars at the southern Missouri site were Essex or Hutcheson (susceptible to H. glycines), Forrest (Peking), Hartwig (PI 437654), and Rhodes (PI 88788 + Peking). In 1995, race tests were performed at four temperature regimes to determine temperature effects on race designations. Race shifts were not predictable based on the source of resistance of the soybean cultivar planted. Variability in female numbers on Lee 74 among tests caused changes in female indices (FI). Furthermore, race designations were influenced by the time of sampling and temperature at which the race tests were conducted. The variability of H. glycines populations in both field and greenhouse situations diminishes the value of race test results when making cultivar recommendations.
种植了具有不同抗大豆胞囊线虫（Heterodera glycines）抗性来源的大豆品种，地点为最初感染了2号、3号和6号生理小种的三个地方，目的是调查田间种群中大豆胞囊线虫生理小种的变化。每年春秋两季，从每个地块采集土壤样本并进行生理小种测试，以评估品种和采样时间的影响。自1991年以来，田间试验采用成对的田间地块，每年与玉米轮作。密苏里州北部和中部地点种植的品种包括Williams 82（对大豆胞囊线虫敏感）、Linford（PI 88788抗性来源）、1995年至1997年被Morsoy 9345（北京和PI 88788）取代的MFA 9043（北京），以及1996 - 1997年被Asgrow 3431（北京和PI 88788）取代的Jackson II（北京 + PI 88788）。密苏里州南部地点种植的品种有Essex或Hutcheson（对大豆胞囊线虫敏感）、Forrest（北京）、Hartwig（PI 437654）和Rhodes（PI 88788 + 北京）。1995年，在四种温度条件下进行生理小种测试，以确定温度对生理小种鉴定的影响。根据种植的大豆品种的抗性来源无法预测生理小种的变化。不同测试中Lee 74上雌虫数量的差异导致了雌虫指数（FI）的变化。此外，生理小种鉴定受采样时间和进行生理小种测试时的温度影响。在提出品种推荐时，田间和温室环境中大豆胞囊线虫种群的变异性降低了生理小种测试结果的价值。
