Agricultural College, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, 530004, China.
College of Agriculture, Yangtze University, Jingzhou, 434025, China.
Theor Appl Genet. 2020 Jun;133(6):2021-2033. doi: 10.1007/s00122-020-03575-3. Epub 2020 Mar 12.
The rice gall midge resistance gene, Gm5, confers remarkable antibiosis and is located in the same region on chromosome 12 in three different rice varieties. Fine mapping narrowed this region to a 49-kb segment and identified two candidate genes showing remarkable response to GM infestation. The Asian rice gall midge (GM; Orseolia oryzae; Diptera: Cecidomyiidae) invades rice shoots and forms galls, adversely affecting plant growth and yield production. Thus, the development of resistant varieties through the identification, mapping, and application of GM resistance genes is considered the most efficient strategy for managing this insect. Here, a GM resistance survey of F populations derived from intercrosses between resistant rice varieties 'ARC5984,' '570011,' and 'ARC5833' indicated that the resistance gene Gm5 was located on the same chromosomal region in the three varieties. For the initial mapping, three independent F mapping populations were developed for the three resistant varieties, and the Gm5 gene was consistently mapped to the same chromosomal region near marker 12M22.6. Fine mapping, which was conducted using the BCF and BCF populations derived from the 9311/ARC5984 cross, narrowed the Gm5 gene region to a 49-kb segment flanked by the markers Z57 and Z64. In the final mapped region, we detected 10 candidate genes, of which six were analyzed for their relative expression. Consequently, two of these genes, Os12g36830 and Os12g36880, showed significantly higher expression in GM-resistant plants than in GM-susceptible plants at 24 and 72 h after GM infestation. Finally, the PCR amplification of markers 12M22.5 and 12M22.6 yielded clear single bands, and these markers were effectively applied for the marker-assisted selection (MAS) of the Gm5 gene. With the developed MAS markers, the fine mapping of this resistance gene will facilitate its map-based cloning and incorporation into insect-resistant rice varieties through breeding.
水稻瘿蚊抗性基因 Gm5 具有显著的抗生性，位于三个不同水稻品种的第 12 号染色体相同区域。精细定位将该区域缩小到 49kb 片段，并鉴定出两个候选基因对 GM 侵染表现出显著反应。亚洲水稻瘿蚊（GM；Orseolia oryzae；双翅目：瘿蚊科）侵袭水稻芽并形成瘿瘤，对植物生长和产量产生不利影响。因此，通过鉴定、定位和应用 GM 抗性基因来培育抗性品种被认为是管理这种昆虫最有效的策略。在这里，对来自抗性水稻品种 'ARC5984'、'570011' 和 'ARC5833' 杂交产生的 F 群体进行的 GM 抗性调查表明，抗性基因 Gm5 位于三个品种的同一染色体区域。对于初步定位，为三个抗性品种分别开发了三个独立的 F 作图群体，Gm5 基因始终被定位在标记 12M22.6 附近的同一染色体区域。使用来自 9311/ARC5984 杂交的 BCF 和 BCF 群体进行精细定位，将 Gm5 基因区域缩小到由标记 Z57 和 Z64 侧翼的 49kb 片段。在最终映射的区域中，我们检测到 10 个候选基因，其中 6 个候选基因的相对表达进行了分析。结果表明，在 GM 抗性植株中，这两个基因 Os12g36830 和 Os12g36880 在 GM 侵染后 24 和 72 小时的表达水平明显高于 GM 敏感植株。最后，标记 12M22.5 和 12M22.6 的 PCR 扩增产生清晰的单条带，这些标记可有效用于 Gm5 基因的标记辅助选择（MAS）。利用开发的 MAS 标记，该抗性基因的精细定位将促进其基于图谱的克隆，并通过育种将其导入抗虫水稻品种。
