Efficient Marker-Assisted Pyramiding of Xa21 and Xa23 Genes into Elite Rice Restorer Lines Confers Broad-Spectrum Resistance to Bacterial Blight

作者：Yao Li, Yulong Fan, Yihang You, Ping Wang, Yuxuan Ling, Han Yin, Yinhua Chen, Hua Zhou, Mingrui Luo, Bing Cao, Zhihui Xia · 发表于：Plants · 年份：2025 · DOI：10.3390/plants14142107 · 被引用次数：5 · 研究领域：Plant Pathogenic Bacteria Studies、Plant-Microbe Interactions and Immunity、Plant Disease Resistance and Genetics

Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major threat to global rice productivity. Although hybrid rice breeding has significantly enhanced yields, persistent genetic vulnerabilities within restorer lines continue to compromise BB resistance. This study addresses this challenge by implementing functional marker-assisted selection (FMAS) to pyramid two broad-spectrum resistance (R) genes, Xa21 and Xa23, into the elite, yet BB-susceptible, restorer line K608R. To enable precise Xa23 genotyping, we developed a novel three-primer functional marker (FM) system (IB23/CB23/IR23). This system complements the established U1/I2 markers used for Xa21. This recombination-independent FMAS platform facilitates simultaneous, high-precision tracking of both homozygous and heterozygous alleles, thereby effectively circumventing the linkage drag limitations typical of conventional markers. Through six generations of marker-assisted backcrossing followed by intercrossing, we generated K608R2123 pyramided lines harboring both R genes in homozygous states, achieving a recurrent parent genome recovery rate of 96.93%, as determined by single nucleotide polymorphism (SNP) chip analysis. The pyramided lines exhibited enhanced resistance against six virulent Xoo pathogenic races while retaining parental yield performance across key agronomic traits. Our FMAS strategy overcomes the historical trade-off between broad-spectrum resistance and the preservation of elite pheno...