玉米穗柄长度主效位点qESL1-2的功能解析及驯化规律研究

穗柄长度与玉米生理成熟期快速脱水及籽粒机械收获相关，选育适宜穗柄长度品种已成为当今玉米育种的新方向。为挖掘穗柄长度有利等位基因，储备栽培玉米改良基因资源，前期利用玉米-大刍草渗入系群体鉴定到控制玉米穗柄长度的主效位点qESL1-2，表型贡献率达到38.12%。通过筛选剩余杂合系构建分离群体已将该QTL精细定位并克隆，LBD转录因子是qESL1-2的重要候选基因。在此基础上，本项目拟对该基因功能开展深入研究，通过遗传转化及候选基因关联分析验证候选基因功能；运用qRT-PCR及原位杂交明确qESL1-2的组织表达特异性；进一步利用转录组测序、ChIP-seq及EMSA等阐明该基因调控玉米穗柄长度的调控网络；利用群体遗传学方法阐明该基因在驯化改良过程中的传递规律。研究结果不仅为适宜机械化收获玉米新品种选育提供功能位点，还为玉米穗柄长度基因鉴定、驯化与改良积累有益资料，具有重要的理论与应用价值。

Ear shank length (ESL) is related to the rapid dehydration and mechanized harvesting at the physiological maturity stage. Breeding maize varieties with suitable ESL has become a new direction of corn breeding. In order to excavate the favorable alleles for ESL, and reserve the improved genetic resources of cultivated maize, previous investigation in our group detected a major QTL(qESL1-2) for ESL by QTL mapping in a maize-teosinte derived population, which account for 38.12% phenotypic variance. Using near-isogenic lines(NILs) derived from a heterogeneous inbred family (HIF), we fine-map and cloned qESL1-2，candidate is a LBD transcription factor (TF) gene, which encoding a LOB domain protein. In this project, we will clarify the biological function of this candidate gene. Overexpression, gene knock-out and candidate gene based association mapping will be used to verify the functions of candidate gene. qRT-PCR and mRNA in situ hubridization will be used to explore the location and expression pattern of qESL1-2. RNA-sequencing, chromatin immunoprecipitation sequencing and electrophoretic mobility shift assay will be used to explore the regulatory network of qESL1-2 comprehensively. Population genetics methods will also used to uelucidate the transfer law of qESL1-2 during maize domestiction and improvement process. The research results not only provide functional sites for the selection of new maize varieties suitable for mechanized harvesting, but also provide useful information for the related genetic identification, domestication and improvement of the ESL of maize, which has important theoretical and practical value.