常规籼稻品种的稻瘟病抗性基因及穗颈瘟抗性分析

目的 明确常规籼稻品种资源所携带的稻瘟病抗性基因及抗性效应。方法 利用PARMS SNP分型技术，检测14个稻瘟病抗性基因在121份常规籼稻品种中的分布情况，并进行田间穗颈瘟自然鉴定，分析基因型和抗性的关系。结果 大多数供试品种携带2~6个稻瘟病抗性基因，Pi46和Pia的检出率较低，分别为3.3%和7.4%；Pi54和Pi5检出率较高，分别为86.0%和67.8%；所有供试品种均不携带Pi9、Pigm、Pik-m和Pik。田间抗性鉴定结果表明，供试品种的穗颈瘟抗性普遍较弱，但广东品种的穗颈瘟抗性明显好于广西品种的；携带的抗性基因数量与穗颈瘟抗性间相关性不显著；Pi2和Pid3对穗颈瘟抗性贡献显著，优势比值分别为5.98和7.50；Pi2⁺Pid3⁺、Pi2⁺Pi33⁺和Pid3⁺Pi33⁺组合的田间穗颈瘟抗性表现较好。结论 本研究结果为两广籼稻区稻瘟病抗性基因聚合育种的亲本选择提供了理论支持，为常规稻的合理布局提供了科学参考。

Analysis of blast resistance genes and panicle neck blast resistances of conventional indica rice varieties

Objective To indentify the blast resistance genes and resistance effects of conventional indica rice variety resources. Method The distribution of 14 blast resistance genes in 121 conventional indica rice varieties were genotyped using PARMS SNP typing technology. Natural identification of panicle neck blast was conducted in the field, and the relationship between genotype and resistance was analyzed. Result Most of the tested varieties carried 2−6 blast resistance genes. The detection rates of Pi46 and Pia were 3.3% and 7.4%, respectively. The detection rates of Pi54 and Pi5 were 86.0% and 67.8%, respectively. None of the tested varieties carried Pi9, Pigm, Pik-m, or Pik. Field resistance identification showed the resistances to panicle neck blast of the tested varieties were generally weak, yet the resistances of Guangdong varieties were significantly higher than those of Guangxi varieties. There was no significant correlation between the number of resistance genes and the resistance to panicle neck blast. Pi2 and Pid3 had significant contributions on the resistance to panicle neck blast, with the odds ratios of 5.98 and 7.50, respectively. The combinations of Pi2⁺Pid3⁺, Pi2⁺Pi33⁺ and Pid3⁺Pi33⁺ showed higher resistance to panicle neck blast. Conclusion The results of this study provides a theoretical support for the parent selection of pyramiding breeding using rice blast resistance genes in the indica rice regions of Guangdong and Guangxi, and provides scientific references for the rational layout of conventional rice.