Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture and Rural Affairs, Northeast Agricultural University, Harbin, 150030, China.
College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, 150030, China.
Theor Appl Genet. 2021 Aug;134(8):2531-2545. doi: 10.1007/s00122-021-03840-z. Epub 2021 Apr 29.
Powdery mildew resistance in zucchini is controlled by one major dominant locus, CpPM10.1. CpPM10.1 was fine mapped. The expression of candidate gene Cp4.1LG10g02780 in resistant individuals was significantly upregulated after inoculation with the powdery mildew. Powdery mildew (PM) is one of the most destructive fungal diseases, reducing the productivity of Cucurbita crops globally. PM influences the photosynthesis, growth and development of infected zucchini and seriously reduces fruit yield and quality. In the present study, the zucchini inbred line 'X10' had highly stable PM resistance, and the inbred line 'Jin234' was highly susceptible to PM in the seedling stage and adult stages. Genetic analysis revealed that PM resistance in 'X10' is controlled by one major dominant locus. Based on the strategy of QTL-seq combined with linkage analysis and developed molecular markers, the major locus was found to be located in a 382.9-kb candidate region on chromosome 10; therefore, the major locus was named CpPM10.1. Using 1,400 F individuals derived from a cross between 'X10' and 'JIN234' and F offspring of the recombinants, the CpPM10.1 locus was defined in a region of approximately 20.9 kb that contained 5 coding genes. Among them, Cp4.1LG10g02780 contained a conserved domain (RPW8), which controls resistance to a broad range of PM pathogens. Cp4.1LG10g02780 also had nonsynonymous SNPs between the resistant 'X10' and susceptible 'Jin234.' Furthermore, the expression of Cp4.1LG10g02780 was strongly positively involved in PM resistance in the key period of inoculation. Further allelic diversity analysis in zucchini germplasm resources indicated that PM resistance was associated with two SNPs in the Cp4.1LG10g02780 RPW8 domain. This study not only provides highly stable PM resistance gene resources for cucurbit crops but also lays the foundation for the functional analysis of PM resistance and resistance breeding in zucchini.
蔓枯病抗性由一个主效显性基因位点 CpPM10.1 控制。CpPM10.1 被精细定位。接种白粉病后，抗性个体中候选基因 Cp4.1LG10g02780 的表达显著上调。白粉病（PM）是最具破坏性的真菌病害之一，全球范围内降低了葫芦科作物的生产力。PM 影响感病南瓜的光合作用、生长和发育，严重降低果实产量和品质。在本研究中，自交系 'X10' 具有高度稳定的 PM 抗性，而自交系 'Jin234' 在幼苗期和成株期对 PM 高度敏感。遗传分析表明，'X10' 中的 PM 抗性由一个主效显性基因位点控制。基于 QTL-seq 结合连锁分析和开发的分子标记策略，发现主效位点位于第 10 号染色体上的一个 382.9-kb 候选区域，因此将该主效位点命名为 CpPM10.1。利用 'X10' 和 'Jin234' 杂交产生的 1400 个 F1 个体和重组体的 F2 后代，将 CpPM10.1 基因座定义在一个约 20.9kb 的区域内，该区域包含 5 个编码基因。其中，Cp4.1LG10g02780 含有一个保守结构域（RPW8），该结构域控制对广泛的 PM 病原体的抗性。在抗性 'X10' 和感病 'Jin234' 之间，Cp4.1LG10g02780 还存在非同义 SNP。此外，在接种的关键时期，Cp4.1LG10g02780 的表达与 PM 抗性呈强烈正相关。在南瓜种质资源中的进一步等位基因多样性分析表明，PM 抗性与 Cp4.1LG10g02780 RPW8 结构域中的两个 SNP 相关。本研究不仅为葫芦科作物提供了高度稳定的 PM 抗性基因资源，还为南瓜 PM 抗性的功能分析和抗性育种奠定了基础。
