Ubon Ratchathani Rice Research Center, Mueang, Ubon Ratchathani, Thailand.
Phrae Rice Research Center, Mueang, Phrae, Thailand.
Mol Biol Rep. 2020 Jun;47(6):4273-4283. doi: 10.1007/s11033-020-05546-9. Epub 2020 May 28.
The rice gall midge (RGM), Orseolia oryzae (Wood-Mason), is one of the most destructive insect pests of rice, and it causes significant yield losses annually in Asian countries. The development of resistant rice varieties is considered as the most effective and economical approach for maintaining yield stability by controlling RGM. Identification of resistance genes will help in marker-assisted selection (MAS) to pyramid the resistance genes and develop a durable resistance variety against RGM in areas with frequent outbreaks. In this study, a mitochondrial cytochrome oxidase subunit I (mtCOI) was used to analyze the genetic diversity among Thai RGM populations. The phylogenetic tree indicated that the Thai RGM populations were homogeneously distributed throughout the country. The reactions of the resistant rice varieties carrying different resistance genes revealed different RGM biotypes in Thailand. The Thai rice landrace MN62M showed resistance to all RGM populations used in this study. We identified a novel genetic locus for resistance to RGM, designated as gm12, on the short arm of rice chromosome 2. The locus was identified using linkage analysis in 144 F plants derived from a cross between susceptible cultivar KDML105 and RGM-resistant cultivar MN62M with single nucleotide polymorphism (SNP) markers and F phenotype. The locus was mapped between two flanking markers, S2_76222 and S2_419160. In conclusion, we identified a new RGM resistance gene, gm12, on rice chromosome 2 in the Thai rice landrace MN62M. This finding yielded DNA markers that can be used in MAS to develop cultivars with broad-spectrum resistance to RGM. Moreover, the new resistance gene provides essential information for the identification of RGM biotypes in Thailand and Southeast Asia.
稻瘿蚊（RGM），Orseolia oryzae（Wood-Mason），是水稻最具破坏性的害虫之一，每年在亚洲国家造成重大产量损失。培育抗虫品种被认为是通过控制 RGM 来维持产量稳定的最有效和经济的方法。鉴定抗性基因将有助于标记辅助选择（MAS）来聚合抗性基因，并在经常爆发的地区开发对 RGM 具有持久抗性的品种。在这项研究中，使用线粒体细胞色素氧化酶亚基 I（mtCOI）分析了泰国 RGM 种群的遗传多样性。系统发育树表明，泰国 RGM 种群在全国范围内均匀分布。携带不同抗性基因的抗性水稻品种的反应表明泰国存在不同的 RGM 生物型。泰国水稻地方品种 MN62M 对本研究中使用的所有 RGM 种群均表现出抗性。我们在水稻第 2 号染色体的短臂上鉴定到一个对 RGM 抗性的新遗传位点，命名为 gm12。该位点是通过在易感性品种 KDML105 和 RGM 抗性品种 MN62M 杂交产生的 144 个 F 植株中，利用单核苷酸多态性（SNP）标记和 F 表型进行连锁分析鉴定的。该位点位于两个侧翼标记 S2_76222 和 S2_419160 之间。总之，我们在泰国水稻地方品种 MN62M 中第 2 号染色体上鉴定到一个新的 RGM 抗性基因 gm12。这一发现产生了可用于 MAS 的 DNA 标记，以开发对 RGM 具有广谱抗性的品种。此外，新的抗性基因为泰国和东南亚 RGM 生物型的鉴定提供了重要信息。
