Genetic Diversity and Breeding of Underutilized Legumes

Underutilized legumes such as winged bean (Psophocarpus tetragonolobus), tepary bean (Phaseolus acutifolius) and yam bean (Pachyrhizus spp.) offer substantial opportunities to diversify agricultural systems, enhance nutritional security and bolster resilience to climate stress. Their inherent drought tolerance, high protein content and wide adaptation have prompted increasing attention to their genetic resources. Studies reveal moderate to high levels of allelic richness, often accompanied by substantial genetic admixture owing to seed exchange and outcrossing. Advances in genome assembly, transcriptome sequencing and high‐density marker development have clarified population structure, identified loci governing key traits such as pod architecture, protein content and phytonutrient accumulation, and provided the foundation for marker-assisted selection. Integrating these molecular tools with conventional breeding—through ideotype definition, quantitative trait locus mapping and genomic selection—facilitates the development of improved cultivars suited to marginal environments and novel production systems.

Research from Nature Portfolio

Recent genomic investigations have delivered a chromosome-level reference for winged bean and characterised the diversity of over a hundred global accessions. Linked genetic maps and expression analyses have pinpointed quantitative trait loci associated with plant architecture, seed protein concentration and phytonutrient profiles, laying the groundwork for accelerated cultivar improvement. In parallel, agronomic trials of tepary bean genotypes under contrasting harvest regimes have demonstrated parity or superiority to soybean in forage biomass, with certain lines offering enhanced feed quality under defined cutting heights and intervals. These findings underscore the potential of tepary bean as both a forage and dual-purpose crop in semi-arid regions. Seminal transcriptomic resources developed for winged bean have also provided a catalogue of simple sequence repeat markers and single nucleotide polymorphisms, underpinning further gene discovery and breeding endeavours.

Genetic Diversity and Breeding of Underutilized Legumes publication trend

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

Technical terms

Germplasm: A collection of genetic resources (seeds, tissues, or plant materials) used for breeding and conservation.

Quantitative trait locus (QTL): A genomic region associated with variation in a quantitative trait such as yield or protein content.

Simple sequence repeat (SSR) marker: A DNA marker based on short tandem repeats, used to assess genetic diversity and linkage mapping.

Marker-assisted selection (MAS): A breeding technique that uses DNA markers linked to desirable traits to accelerate cultivar development.

Transcriptome: The complete set of RNA transcripts produced by the genome under specific conditions, used for gene discovery and expression studies.

References

1. A genomic toolkit for winged bean Psophocarpus tetragonolobus. Nature Communications (2024).
2. Biochemical composition, bioactivity, processing, and food applications of winged bean (Psophocarpus tetragonolobus): A review. Legume Science (2023).
3. Effect of cutting management on the forage production and quality of tepary bean (Phaseolus acutifolius A. Gray). Scientific Reports (2023).
4. Molecular genetic diversity of winged bean gene pool in Thailand assessed by SSR markers. Horticultural Plant Journal (2022).
5. Transcriptome sequencing and marker development in winged bean (Psophocarpus tetragonolobus; Leguminosae). Scientific Reports (2016).
6. Dual-Purpose of the Winged Bean (Psophocarpus tetragonolobus (L.) DC.), the Neglected Tropical Legume, Based on Pod and Tuber Yields. Plants (2021).