ShanXi agricultural university
Key R&D Plan of Shanxi Province (202102140601002-1); Sub project of Shanxi Provincial Science and Technology Major Special Plan (202201140601025-01-03); Special funding for the construction of modern agricultural industry technology system in Shanxi Province; Central Guiding Local Development Fund Project (YDZJSX2022A036); Biological Breeding Project of Shanxi Agricultural University (YZGC146); Shanxi Province Corn Variety Joint Research Project.
本研究以134份玉米自交系为实验材料，对玉米的9个苗期根系性状进行表型鉴定，并利用分布于玉米基因组的44935个SNP标记，基于FarmCPU模型进行全基因组关联分析(Genome-wide association study, GWAS)。结果表明9个根系性状表型变异范围在10.86%-55.96%之间，大部分表型间相关性达极显著水平(P<0.001)，侧根长和总根长相关系数最高，为0.996，其次为侧根数与总根数达到0.993。共鉴定到32个显著关联的SNP位点(P=1.01e-11-9.74e-5)，表型贡献率在0.54%-22.34%之间，主根长、总根长、最大根长、侧根长分别检测到4、8、3、9个显著的SNP位点；总根数、侧根数、不定根数分别检测到10、7、1个显著SNP位点；14个SNP位点同时与多个根系性状关联。12个显著关联位点位于已知根系相关性状QTL(Quantitative trait loci)区间内。共发掘49个根系候选基因，其中GRMZM2G028386 (ABI4)、GRMZM2G135713(PUB23)、GRMZM5G870592(MYB98)、GRMZM2G156861(LOX1)、GRMZM2G160005(AUX16)、GRMZM2G126936(NAC2)等是重要的根系候选基因。本研究为克隆玉米根系发育相关基因，解析玉米根系发育分子机制提供了重要参考。
In this study, 134 maize inbred lines were used as experimental materials to conduct phenotypic identification of 9 root traits at seedling stage of maize, and 44935 SNP markers distributed in maize genome were used to conduct Genome-wide association study (GWAS) based on FarmCPU model. The results showed that the phenotypic variation range of 9 root traits ranged from 10.86% to 55.96%, and the correlation between most phenotypes reached a highly significant level (P<0.001). The correlation coefficient between lateral root length and total root length was the highest, reaching 0.996, followed by the number of lateral roots and total roots reaching 0.993. A total of 32 significantly associated SNP loci were identified (P=1.01e-11-9.74e-5), with phenotypic contribution rates ranging from 0.54% to 22.34%. 4, 8, 3, and 9 significant SNP loci were detected for main root length, total root length, maximum root length, and lateral root length, respectively; 10, 7, and 1 significant SNP loci were detected for total root number, lateral root number, and adventitious root number, respectively; 14 SNP loci are associated with multiple root traits simultaneously. Twelve significant association sites are located within the known QTL (Quantitative trait loci) range of root related traits. A total of 49 root candidate genes were identified, among which GRMZM2G028386 (ABI4), GRMZM2G135713 (PUB23), GRMZM5G870592 (MYB98), GRMZM2G156861 (LOX1), GRMZM2G160005 (AUX16), GRMZM2G126936 (NAC2) and other important root candidate genes were identified. This study provides important reference for cloning genes related to maize root development and analyzing the molecular mechanisms of maize root development.