• Rice blast, caused by Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The identification and utilization of resistance genes are crucial and significant for breeding resistant rice cultivars.
• We identified a resistance gene from Shuangkang77009, which is highly resistant to the rice blast isolate Guy11 using map‐based cloning. We performed bulked segregant analysis combined with specific length amplified fragment sequencing. We also performed association analysis, candidate gene prediction and cDNA sequencing to identify the candidate gene.
• The resistance gene is located on chromosome 6, and we ultimately mapped the resistance locus to a 92‐kb region. The resistance gene in Shuangkang77009 was allelic to PigmR, hereafter referred to as Pigm‐1. The Pigm‐1 protein had one amino acid change: serine (Ser) residue 860 was replaced by tyrosine (Tyr) in Pigm‐1 compared with the previously identified Pigm protein, which significantly changed the structure of the Pigm‐1 protein based on 3‐D structure simulation. In addition, using the developed molecular marker linked to the Pigm‐1 gene and molecular marker‐assisted selection technology, we introduced the Pigm‐1 gene into Minghui86, a widely used and excellent restorer. We generated 11 stable homozygous rice lines with desirable agronomic traits and strong resistance to rice blast.
• In conclusion, Pigm‐1, a natural allelic variant of PigmR, was responsible for blast resistance in Shuangkang77009 rice. The molecular marker‐assisted breeding strategy for Pigm‐1 was highly efficient.

中文翻译：

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Pigm-1基因在水稻抗病育种中的鉴定与应用。

• 由稻瘟病菌引起的稻瘟病是全世界稻米中最具破坏性的疾病之一。抗性基因的鉴定和利用对于培育抗性水稻品种至关重要。
• 我们从双康77009中鉴定了一个抗性基因，该基因使用基于图谱的克隆对稻瘟病菌株Guy11具有高度抗性。我们进行了大片段分离物分析，并结合了特定长度的扩增片段测序。我们还进行了关联分析，候选基因预测和cDNA测序，以鉴定候选基因。
• 抗药性基因位于第6号染色体上，我们最终将抗药性基因座定位在92kb区域。双康77009中的抗性基因与PigmR等位基因，以下称为Pigm-1。Pigm-1蛋白具有一个氨基酸变化：与先前鉴定的Pigm蛋白相比，Pigm-1中的丝氨酸（Ser）残基860被酪氨酸（Tyr）取代，这显着改变了Pigm-1蛋白的结构，基于3 ‐D结构仿真。此外，利用与Pigm- 1基因相关联的已开发分子标记和分子标记辅助选择技术，我们引入了Pigm-1该基因进入了Minghui86，一种广泛使用的优秀恢复基因。我们产生了11个稳定的纯合水稻系，具有理想的农艺性状和对稻瘟病的强抗性。
• 总之，Pigm-1是PigmR的天然等位基因变体，是双康77009稻瘟病抗性的原因。Pigm-1的分子标记辅助育种策略非常高效。