以本地玉米和野生近缘属矮秆高粱经远缘杂交后再回交得到1份新的矮秆材料d8227为试验材料，通过农艺性状调查、茎秆细胞学观察、外源激素处理、内源激素含量测定来阐述d8227的矮化机理。在课题组前期初定位的基础上，利用图位克隆进行精细定位，为矮秆基因的克隆和功能验证奠定基础。结果表明，与野生型相比，d8227的株高、穗位高降低达极显著水平，d8227的矮化主要是由穗下节间数目的减少和纵切细胞长度的缩短导致。d8227对GA₃、IAA、BR均不敏感，其矮化可能是由细胞分裂素信号转导途径异常引起的。通过图位克隆将控制玉米d8227的矮秆基因定位于玉米第1条染色体标记InDel9420和InDel088之间，物理距离约为377 Kb。对定位区间内3个候选基因进行表达分析，发现只有Zm00001d031894在d8227和野生型幼苗期的相对表达量差异达显著水平，且该基因在玉米的分生组织中具有很高的表达量，对茎秆生长具有一定的影响，因此将Zm00001d031894确定为关键候选基因。

Local maize and wild related dwarf sorghum were distantly hybridized and then backcrossed to obtain a new dwarf material d8227 as the test material. The dwarfing mechanism of d8227 was elucidated by investigating agronomic traits, conducting stem cytological observations, applying exogenous hormone treatments, and measuring endogenous hormone contents. Based on the preliminary positioning of the research team, map-based cloning was used for fine positioning, laying the foundation for the cloning and functional verification of dwarf genes. The study found that compared with the wild type, the plant height and ear height of d8227 were significantly reduced. The dwarfing of d8227 was mainly caused by the reduction in the number of internodes under the ear and the shortening of the length of longitudinally cut cells. The dwarf line d8227 was found to be insensitive to GA3, IAA, and BR, and its dwarfism may be caused by abnormalities in the cytokinin signal transduction pathway. The dwarf gene controlling maize d8227 was located between the markers InDel9420 and InDel088 on the first chromosome of maize through map-based cloning, with a physical distance of approximately 377 Kb. Expression analysis of three candidate genes within the positioning interval found that only Zm00001d031894 had a significant difference in relative expression between the d8227 and wild-type seedling stages, and this gene has a high expression level in the meristem of maize, which is important for stem growth has a certain impact, so Zm00001d031894 was identified as a key candidate gene.

S513.035.3

国家重点研发计划项目(2016YFD0300309)