Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, China.
Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, China.
Mol Genet Genomics. 2019 Dec;294(6):1421-1440. doi: 10.1007/s00438-019-01586-4. Epub 2019 Jul 9.
Maize tassel architecture is a complex quantitative trait that is significantly correlated with biomass yield and grain yield. The present study evaluated the major trait of maize tassel architecture, namely, tassel branch number (TBN), in an association population of 359 inbred lines and an IBM Syn 10 population of 273 doubled haploid lines across three environments. Approximately 43,958 high-quality single nucleotide polymorphisms were utilized to detect significant QTNs associated with TBN based on new multi-locus genome-wide association study methods. There were 30, 38, 73, 40, 47, and 53 QTNs associated with tassel architecture that were detected using the FastmrEMMA, FastmrMLM, EM-BLASSO, mrMLM, pkWMEB, and pLARmEB models, respectively. Among these QTNs, 51 were co-identified by at least two of these methods. In addition, 12 QTNs were consistently detected across multiple environments. Furthermore, 19 QTLs distributed on chromosomes 1, 2, 3, 4, 6, and 7 were detected in 3 environments and the BLUP model based on 6618 bin markers, which explained 3.64-10.96% of the observed phenotypic variations in TBN. Of these, three QTLs were co-detected in two environments. One QTN associated with TBN was localized to one QTL. Approximately 55 candidate genes were detected by common QTNs and LD criteria. One candidate gene, Zm00001d016615, was identified as a putative target of the RA1 gene. Meanwhile, RA1 was previously validated to plays an important role in tassel development. In addition, the newly identified candidate genes Zm00001d003939, Zm00001d030212, Zm00001d011189, and Zm00001d042794 have been reported to involve in a spikelet meristem identity module. The findings of the present study improve our understanding of the genetic basis of tassel architecture in maize.
玉米雄穗结构是一个复杂的数量性状，与生物量和籽粒产量显著相关。本研究在三个环境下，评估了玉米雄穗结构的主要性状，即雄穗分枝数（TBN），在一个由 359 个自交系组成的关联群体和一个 IBM Syn 10 的 273 个双单倍体群体中进行了评估。利用大约 43958 个高质量的单核苷酸多态性，基于新的多基因全基因组关联研究方法，检测与 TBN 显著相关的 QTNs。利用 FastmrEMMA、FastmrMLM、EM-BLASSO、mrMLM、pkWMEB 和 pLARmEB 模型，分别检测到 30、38、73、40、47 和 53 个与雄穗结构相关的 QTN。其中，51 个 QTN 至少被两种方法共同鉴定。此外，有 12 个 QTN 在多个环境中被一致检测到。此外，在三个环境中，基于 6618 个 bin 标记的 BLUP 模型，检测到分布在 1、2、3、4、6 和 7 号染色体上的 19 个 QTL，解释了 TBN 表型变异的 3.64-10.96%。其中，有三个 QTL在两个环境中共同检测到。一个与 TBN 相关的 QTN 被定位到一个 QTL 上。通过共同的 QTN 和 LD 标准，检测到大约 55 个候选基因。一个候选基因 Zm00001d016615，被鉴定为 RA1 基因的一个假定靶点。同时，RA1 先前已被验证在雄穗发育中起重要作用。此外，新鉴定的候选基因 Zm00001d003939、Zm00001d030212、Zm00001d011189 和 Zm00001d042794 已被报道参与小穗分生组织身份模块。本研究的结果提高了我们对玉米雄穗结构遗传基础的理解。
