Genetic Variability and Genomic Regions Associated with Root System Architecture Traits in Ethiopian Sorghum Accessions for Enhanced Drought Tolerance

  • SorghumBase Team
  • 17 June 2024

Sorghum (Sorghum bicolor L. Moench) is a crucial cereal crop, particularly in sub-Saharan Africa, serving as a staple food and providing energy, protein, and other essential nutrients. Despite its importance, sorghum productivity faces challenges from various biotic and abiotic stresses, with drought being a significant limiting factor. Root system architecture (RSA) plays a critical role in drought adaptation, making it essential to understand the genetic basis of RSA traits for sorghum improvement.

Scientists from Haramaya University, Kansas State University, the Ethiopia Agricultural Transformation Institute, the USDA-ARS, the Ethiopian Institute of Agricultural Research (EIAR) and Jimma University investigated the genetic variability and genomic regions associated with RSA traits in a panel of 274 Ethiopian sorghum accessions to enhance sorghum’s tolerance to environmental stress. Utilizing multiple methodologies, including multi-locus genome-wide association study (ML-GWAS) with 265,944 high-quality single nucleotide polymorphism markers, the study identifies 17 reliable quantitative trait nucleotides (QTNs) significantly linked to root angle, number, length, and dry weight. These QTNs, located on chromosomes SBI-01, SBI-02, and SBI-05, include both previously identified and novel genomic regions, with 118 genes colocated with the QTNs. Additionally, the study highlights five intragenic QTNs, three of which are associated with genes responsible for plant growth hormone-induced RSA, offering potential targets for further genetic exploration to enhance sorghum’s root development in drought-prone regions. The findings provide valuable insights into enhancing sorghum’s drought tolerance through genetic improvement of its root system architecture.

A complex dance of survival:  Seedling root angle and length are key elements in sorghum’s drought adaptation strategy, working in tandem with other factors like leaf morphology and physiological responses to optimize water uptake and minimize stress. – Menamo

SorghumBase examples:

Figure 1: The Sobic.010G198000 gene maps to a region with QTLs for plant height, days to flowering, grain yield, etc. Within the gene’s span is S10_55702393 (likely rs162459475), one of the intragenic QTNs associated with the number of nodal roots that was found responsible for the plant growth hormone-induced RSA in this study.
Figure 2: Genetic variation for Sobic.010G198000 (coordinates correspond to v3).

Reference:

Elias M, Chere D, Lule D, Serba D, Tirfessa A, Gelmesa D, Tesso T, Bantte K, Menamo TM. Multi-locus genome-wide association study reveal genomic regions underlying root system architecture traits in Ethiopian sorghum germplasm. Plant Genome. 2024 Feb 15:e20436. PMID: 38361379. doi: 10.1002/tpg2.20436. Read more

Related Project Website:

The Plant and Animal Biotechnology Research Center at Jimma University: https://ju.edu.et/plant-and-animal-biotechnology-research-center/ 

A

B

C

D

Image 1: High-throughput root phenotyping platform for sorghum genotype at seedling stage in Jimma University; A, The whole platform, B, sorghum genotype at drought stress condition, C & D  root visibility at 5th leaf stage.