Department of Plant Pathology, North Dakota State University, Fargo, ND 58108.
Department of Plant Sciences, North Dakota State University, Fargo, ND 58108.
Plant Dis. 2022 Aug;106(8):2117-2126. doi: 10.1094/PDIS-11-21-2444-RE. Epub 2022 Jul 19.
Two greenhouse experiments were conducted with the new species of root-lesion nematode, , discovered in North Dakota, USA in 2017 and named in 2021. Experiment 1 was conducted to ascertain resistance levels of soybean ( [L.] Merr.) cultivars to the new species and Experiment 2 was conducted to evaluate the population levels of in roots versus soil. A total of 20 soybean cultivars, and the positive control, cultivar Barnes, accompanying a nonplanted control, were evaluated in both experiments; they each had five replicates and the experiments were repeated. Among the 20 soybean cultivars evaluated, a cultivar with the ID# 13 consistently produced the greatest population densities of across all the experiments and therefore it was selected as the susceptible check. The ratio of the final nematode population density of a test cultivar relative to the final population density of the susceptible check was used to scale resistance rating. Combined results of all the trials indicated that seven of the cultivars were moderately resistant, nine of the cultivars plus 'Barnes' were moderately susceptible, and four of the cultivars were susceptible. However, none of the cultivars tested were classified as resistant. Analysis of population levels revealed that ≥50% of the population resided in the root habitat and the remaining nematodes were recovered from soil at 9 weeks after planting for a majority of the cultivars tested. These results provide an insight into the virulence of on commercial soybean cultivars.
2017 年在美国北达科他州发现了一种新的根结线虫物种，并于 2021 年命名。进行了两项温室实验，以确定大豆（[L.] Merr.）品种对新物种的抗性水平，实验 1 旨在确定大豆品种对新物种的抗性水平，实验 2 旨在评估根内和土壤中的种群水平。在这两项实验中，共评估了 20 个大豆品种和阳性对照品种 Barnes，以及一个非种植对照品种；每个品种有 5 个重复，实验重复进行。在评估的 20 个大豆品种中，品种 ID# 13 consistently produced the greatest population densities of across all the experiments and therefore it was selected as the susceptible check. 在所有实验中，品种 ID# 13 consistently produced the greatest population densities of consistently 产生了最大的种群密度，因此它被选为易感对照。The ratio of the final nematode population density of a test cultivar relative to the final population density of the susceptible check was used to scale resistance rating. 测试品种的最终线虫种群密度与易感对照的最终种群密度的比值用于对抗性等级进行评分。Combined results of all the trials indicated that seven of the cultivars were moderately resistant, nine of the cultivars plus 'Barnes' were moderately susceptible, and four of the cultivars were susceptible. However, none of the cultivars tested were classified as resistant. 所有试验的综合结果表明，有 7 个品种中度抗性，9 个品种加 Barnes 中度敏感，4 个品种敏感。然而，没有一个测试品种被归类为抗性。Analysis of population levels revealed that ≥50% of the population resided in the root habitat and the remaining nematodes were recovered from soil at 9 weeks after planting for a majority of the cultivars tested. 对种群水平的分析表明，≥50%的种群栖息在根区，其余线虫在种植后 9 周从土壤中回收，大多数测试品种均如此。These results provide an insight into the virulence of on commercial soybean cultivars. 这些结果深入了解了该线虫对商业大豆品种的毒力。
