Fine mapping of a dominantly inherited powdery mildew resistance major-effect QTL, Pm1.1, in cucumber identifies a 41.1 kb region containing two tandemly arrayed cysteine-rich receptor-like protein kinase genes
Fine mapping of a dominantly inherited powdery mildew resistance major-effect QTL, Pm1.1, in cucumber identifies a 41.1 kb region containing two tandemly arrayed cysteine-rich receptor-like protein kinase genes
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DOI：
10.1007/s00122-015-2644-4
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发表时间：
2015-12
影响因子：
5.4
通讯作者：
Xuewen Xu;Ting Yu;Ruixue Xu;Yang Shi;Xiaojian Lin;Qiang Xu;X. Qi;Y. Weng;Xuehao Chen
中科院分区：
文献类型：
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作者：
Xuewen Xu;Ting Yu;Ruixue Xu;Yang Shi;Xiaojian Lin;Qiang Xu;X. Qi;Y. Weng;Xuehao Chen
对黄瓜抗白粉病的显性遗传主效QTL进行了精细定位。两个串联排列的富含半胱氨酸受体样蛋白激酶基因被确定为最可能的候选基因。摘要白粉病是黄瓜（Cucumis sativusL.）等瓜类作物最严重的真菌病害之一，但目前对黄瓜抗白粉病的分子遗传机制尚不清楚。本研究通过对黄瓜优质自交系D8 （PM易感）的标记辅助回交，培育出一份单片段代换系SSSL0.7，该代换系携带95 kb片段，来自于抗PM供体Jin5-508，由两个微卫星标记SSR16472和SSR16881确定。以SSSL0.7 × D8杂交组合为基础，培育出3600株f2的分离群体；分离分析证实，SSSL0.7中黄瓜1号染色体上有一个显性遗传的主效QTL pm1.1。通过探索Jin5-508和D8的下一代重测序基因组，开发了新的分子标记。f2植物亚群的连锁分析和QTL定位将pm1.1位点划分为41.1 kb的区域，其中预测了8个基因。比较基因表达分析显示，两个串联基因csa1m064780和csa1m064790编码一种富含半胱氨酸的受体样蛋白激酶的相同功能，是最有可能的候选基因。GFP融合蛋白辅助亚细胞定位表明，这两个候选基因都位于质膜上，但csa1m064780也在细胞核中发现。这是黄瓜中首次报道的显性遗传PM抗性。本研究结果将为了解黄瓜抗PM的表型和遗传机制提供新的见解。该研究也为黄瓜抗PM的标记辅助选择提供了依据。
Key messageA dominantly inherited major-effect QTL for powdery mildew resistance in cucumber was fine mapped. Two tandemly arrayed cysteine-rich receptor-like protein kinase genes were identified as the most possible candidates.AbstractPowdery mildew (PM) is one of the most severe fungal diseases of cucumber (Cucumis sativusL.) and other cucurbit crops, but the molecular genetic mechanisms of powdery mildew resistance in cucurbits are still poorly understood. In this study, through marker-assisted backcrossing with an elite cucumber inbred line, D8 (PM susceptible), we developed a single-segment substitution line, SSSL0.7, carrying 95 kb fragment from PM resistance donor, Jin5-508, that was defined by two microsatellite markers, SSR16472 and SSR16881. A segregating population with 3600 F2plants was developed from the SSSL0.7 × D8 mating; segregation analysis confirmed a dominantly inherited major-effect QTL,Pm1.1in cucumber chromosome 1 underlying PM resistance in SSSL0.7. New molecular markers were developed through exploring the next generation resequenced genomes of Jin5-508 and D8. Linkage analysis and QTL mapping in a subset of the F2plants delimited thePm1.1locus into a 41.1 kb region, in which eight genes were predicted. Comparative gene expression analysis revealed that two concatenated genes,Csa1M064780andCsa1M064790encoding the same function of a cysteine-rich receptor-like protein kinase, were the most likely candidate genes. GFP fusion protein-aided subcellular localization indicated that both candidate genes were located in the plasma membrane, butCsa1M064780was also found in the nucleus. This is the first report of dominantly inherited PM resistance in cucumber. Results of this study will provide new insights into understanding the phenotypic and genetic mechanisms of PM resistance in cucumber. This work should also facilitate marker-assisted selection in cucumber breeding for PM resistance.