Dorrance A E, Schmitthenner A F
Department of Plant Pathology, The Ohio State University, Wooster 44691-4096.
Plant Dis. 2000 Dec;84(12):1303-1308. doi: 10.1094/PDIS.2000.84.12.1303.
Single dominant Rps genes have been highly effective in managing Phytophthora sojae. However, numerous physiological races of P. sojae have developed in response to deploying single gene resistance. New sources of resistance with potentially novel Rps genes are needed. A selection of accessions (PI273483 to PI427107) from the United States Department of Agriculture Soybean Germplasm collection were evaluated for resistance to P. sojae using the hypocotyl inoculation technique for Rps genes and the layer test for partial resistance. Of the 1,015 accessions tested, 159 accessions were susceptible to races 7 (vir 1a, 2, 3a, 3c, 4, 5, 6, 7), 17 (1b, 1d, 2, 3a, 3b, 3c, 4, 5, 6, 7), and 25 (1a, 1b, 1c, 1k, 7). However, 162 accessions were resistant to these three races and 32 accessions were resistant to an additional five races chosen specifically to elicit a susceptible interaction with two and three Rps gene combinations. In addition, 55.5% of the 887 accessions tested had high levels of partial resistance or tolerance (scores ≤4.0) to P. sojae. The majority of the accessions that were resistant to all of the races tested and those that had very high levels of partial resistance originated in the Republic of Korea. These results indicate that this region is an area with many sources of resistance to P. sojae for both specific Rps genes and partial resistance.
单一显性的Rps基因在防治大豆疫霉方面一直非常有效。然而，随着单一基因抗性的应用，大豆疫霉出现了许多生理小种。因此，需要具有潜在新型Rps基因的新抗性来源。利用下胚轴接种技术检测Rps基因，并通过分层试验检测部分抗性，对美国农业部大豆种质资源库中挑选的一批种质（PI273483至PI427107）进行了大豆疫霉抗性评估。在测试的1015份种质中，159份对7号小种（毒性因子1a、2、3a、3c、4、5、6、7）、17号小种（1b、1d、2、3a、3b、3c、4、5、6、7）和25号小种（1a、1b、1c、1k、7）敏感。然而，有162份种质对这三个小种具有抗性，32份种质对另外特意挑选的五个小种具有抗性，这五个小种旨在与两个和三个Rps基因组合引发敏感反应。此外，在测试的887份种质中，55.5%对大豆疫霉具有高水平的部分抗性或耐受性（评分≤4.0）。对所有测试小种均具有抗性以及具有非常高水平部分抗性的种质大多原产于韩国。这些结果表明，该地区是一个对大豆疫霉具有多种抗性来源的区域，包括特定的Rps基因和部分抗性。
