Genetic Diversity and Trait Mapping in Sorghum

Sorghum bicolor stands as a genetically diverse C4 cereal cultivated for grain, forage, sugar and bioenergy across semi‐arid regions worldwide. This diversity stems from multiple domestication events in Africa, extensive landrace variation and a rich wild gene pool. Advances in whole‐genome sequencing, high‐density linkage maps and comprehensive transcriptome atlases have revealed millions of nucleotide variants and indels across global germplasm panels. Such resources underpin quantitative trait locus (QTL) studies and genome‐wide association analyses that identify genomic regions controlling plant height, grain size, drought tolerance, disease resistance and bioenergy characteristics. Comparative genomics with rice and maize has illuminated conserved genetic networks, while wild relatives offer novel alleles for stress resilience. Integration of mapping data with marker‐assisted selection is accelerating the development of improved sorghum cultivars tailored to diverse agroecosystems and emerging bioenergy demands.

Research from Nature Portfolio

Recent studies have fine-mapped and characterised two major stem-length loci. The first revealed that Dw1 encodes a novel protein whose loss of function reduces cell proliferation in internodes, producing semi-dwarf sorghum lines with enhanced lodging resistance. Functional assays demonstrated a synergistic effect between Dw1 and the auxin transporter Dw3, offering a route to optimise plant architecture. A second study identified Dw2 as an AGCVIII family protein kinase that modulates internode length. Natural allelic variation at Dw2 underlies differences in stem height among grain sorghum varieties, providing molecular targets for breeding programmes aimed at mechanised harvesting and reduced lodging.

Genetic Diversity and Trait Mapping in Sorghum publication trend

The graph below shows the total number of articles in genetic diversity and trait mapping in sorghum across all publications each year (not limited to Nature Index journals).

Technical terms

Quantitative trait locus (QTL): A genomic region statistically associated with variation in a measurable trait.

Genome-wide association study (GWAS): A population-scale analysis that correlates genetic variants with phenotypic traits.

Single nucleotide polymorphism (SNP): A single base variation in the DNA sequence among individuals.

Linkage map: A representation of relative marker positions along chromosomes based on recombination frequencies.

References

1. The Sorghum bicolor reference genome: improved assembly, gene annotations, a transcriptome atlas, and signatures of genome organization. The Plant Journal (2017).
2. A consensus genetic map of sorghum that integrates multiple component maps and high-throughput Diversity Array Technology (DArT) markers. BMC Plant Biology (2009).
3. A Sorghum bicolorexpression atlas reveals dynamic genotype-specific expression profiles for vegetative tissues of grain, sweet and bioenergy sorghums. BMC Plant Biology (2014).
4. Wild Sorghum as a Promising Resource for Crop Improvement. Frontiers in Plant Science (2020).
5. Genetic analysis of inflorescence and plant height components in sorghum (Panicoidae) and comparative genetics with rice (Oryzoidae). BMC Plant Biology (2015).
6. Sorghum Dw1, an agronomically important gene for lodging resistance, encodes a novel protein involved in cell proliferation. Scientific Reports (2016).
7. Sorghum Dw2 Encodes a Protein Kinase Regulator of Stem Internode Length. Scientific Reports (2017).
8. Construction of a high-density genetic linkage map and QTL mapping for bioenergy-related traits in sweet sorghum [Sorghum bicolor (L.) Moench]. Frontiers in Plant Science (2023).
9. Genome-Wide Association Study of Seed Morphology Traits in Senegalese Sorghum Cultivars. Plants (2023).
10. Large‐scale GWAS in sorghum reveals common genetic control of grain size among cereals. Plant Biotechnology Journal (2019).