Mitiku Abel Debebe, Feyissa Tileye, Woldetensaye Alemu Tirfessa, Chikssa Habte Nida, Menamo Temesgen Matiwos, Abebe Tewodros Mesfin, Bante Kassahun
Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Melkassa Agricultural Research Center, P.O. Box 436, Nazreth, Ethiopia.
BMC Plant Biol. 2025 Sep 2;25(1):1180. doi: 10.1186/s12870-025-07271-6.
Drought is a major constraint to sorghum production. Developing drought-tolerant sorghum varieties is crucial. Optimal root system architecture (RSA) plays a vital role in plant adaptation and productivity under water- limited environment. Genetic assessments of untapped Ethiopian core sorghum germplasm to identify quantitative trait nucleotides (QTN) for RSA traits are crucial. Therefore, this study aimed to identify genetic markers associated with seven RSA and related traits in 182 Ethiopian core sorghum-landraces using multi locus genome-wide association studies (ML-GWAS) using SNP markers.
The germplasm exhibited substantial phenotypic variation for all measured traits. Genome-wide association analysis identified 181 significant QTNs (LOD ≥ 4) associated with nodal root angle (NRA), shoot traits (length, number, dry weight), and RSA (angle, number, dry weight) across six multi-locus GWAS models. Notably, 73 of these QTNs were consistently detected by at least two ML-GWAS methods. A total of 132 potential candidate genes, ranging from 13 to 25 genes per marker trait for the QTNs, were found about 18kbp LD decay of the significant QTNs using biomaRt. Of these, 13 genes were functionally annotated and involved in various biological processes.
Following the validation of candidate genes for root architecture and related traits, the core collection can be utilized to develop water-efficient sorghum varieties.
干旱是高粱生产的主要限制因素。培育耐旱高粱品种至关重要。最佳根系结构（RSA）在水分受限环境下的植物适应性和生产力中起着至关重要的作用。对未开发的埃塞俄比亚核心高粱种质进行遗传评估，以确定RSA性状的数量性状核苷酸（QTN）至关重要。因此，本研究旨在利用单核苷酸多态性（SNP）标记，通过多位点全基因组关联研究（ML-GWAS），在182份埃塞俄比亚核心高粱地方品种中鉴定与7个RSA及相关性状相关的遗传标记。
种质在所有测量性状上表现出显著的表型变异。全基因组关联分析在六个多位点GWAS模型中鉴定出181个与节根角度（NRA）、地上部性状（长度、数量、干重）和RSA（角度、数量、干重）相关的显著QTN（LOD≥4）。值得注意的是，这些QTN中的73个至少通过两种ML-GWAS方法被一致检测到。使用biomaRt在显著QTN的约18kbp连锁不平衡衰减范围内，共发现132个潜在候选基因，每个标记性状的候选基因数量为13至25个。其中，13个基因具有功能注释，并参与各种生物学过程。
在验证了根系结构及相关性状的候选基因后，核心种质可用于培育水分利用高效的高粱品种。
