Department of Entomology, The Ohio State Univ/OARDC, 1680 Madison Avenue, Wooster, OH 44691, USA.
Theor Appl Genet. 2012 Oct;125(6):1159-68. doi: 10.1007/s00122-012-1902-y. Epub 2012 Jun 13.
Powdery mildew (PMD) of soybean [Glycine max (L.) Merr.] is caused by the fungus Microsphaera diffusa. Severe infection of PMD on susceptible varieties often causes premature defoliation and chlorosis of the leaves, which can result in considerable yield losses under favorable environmental conditions for disease development in the field. A total of 334 F(7)-derived recombinant inbred lines (RILs) from a cross of a PMD susceptible soybean cultivar Wyandot and PMD-resistant PI 567301B were used for genetic mapping of PMD resistance in PI 567301B and for development of molecular markers tightly linked to the gene. The result of the PMD screening for each line in the field was in agreement with that in the greenhouse test. The genetic map containing the PMD resistance gene was constructed in a 3.3 cM interval flanked by two simple sequence repeat (SSR) markers on chromosome 16. The PMD resistance gene was mapped at the same location with SSR marker BARCSOYSSR_16_1291, indicating that there was no recombination between the 334 RILs and this marker. In addition, a single nucleotide polymorphism (SNP) marker developed by high-resolution melting curve analysis and a cleaved amplified polymorphic sequence (CAPS) marker with Rsa1 recognition site were used for the genetic mapping. These two markers were also mapped to the same genomic location with the PMD resistance gene. We validated three tightly linked markers to the PMD resistance gene using 38 BC(6)F(2) lines and corresponding BC(6)F(2:3) families. The three marker genotypes of the backcross lines predicted the observed PMD phenotypes of the lines with complete accuracy. We have mapped a putatively novel single dominant PMD resistance gene in PI 567301B and developed three new molecular markers closely linked to the gene. Molecular markers developed from this study may be used for high-throughput marker-assisted breeding for PMD resistance with the gene from PI 567301B.
大豆[ Glycine max (L.) Merr.]白粉病由 Microsphaera diffusa 真菌引起。在易感品种上，白粉病严重感染常导致叶片过早落叶和黄化，在田间有利于病害发展的环境条件下，会导致相当大的产量损失。利用来自易感大豆品种 Wyandot 和抗白粉病 PI 567301B 的杂交后代的 334 个 F(7)衍生重组自交系 (RIL)，对 PI 567301B 中的白粉病抗性进行了遗传作图，并开发了与该基因紧密连锁的分子标记。田间每条系的白粉病筛选结果与温室试验结果一致。含有白粉病抗性基因的遗传图谱在 16 号染色体上两个简单序列重复 (SSR) 标记侧翼的 3.3 cM 区间构建。将白粉病抗性基因定位在与 SSR 标记 BARCSOYSSR_16_1291 相同的位置，表明在 334 个 RIL 与该标记之间没有重组。此外，还利用高分辨率熔解曲线分析开发了一个单核苷酸多态性 (SNP) 标记和一个具有 Rsa1 识别位点的切割扩增多态性序列 (CAPS) 标记进行遗传作图。这两个标记也与白粉病抗性基因定位在同一基因组位置。利用 38 个 BC(6)F(2)系及其相应的 BC(6)F(2:3)家系，对与白粉病抗性基因紧密连锁的三个标记进行了验证。回交系的三个标记基因型完全准确地预测了系的白粉病表型。我们在 PI 567301B 中定位了一个假定的新型单显性白粉病抗性基因，并开发了三个与该基因紧密连锁的新分子标记。该研究开发的分子标记可用于利用 PI 567301B 中的基因进行高通量标记辅助白粉病抗性选育。
