Genetic Diversity and Improvement of Tuber Crops

The genetic diversity of tuber crops such as yam (Dioscorea spp.), potato (Solanum spp.), cassava (Manihot esculenta) and sweet potato (Ipomoea batatas) underpins global food security and nutrition. Diverse landraces and wild relatives harbour valuable alleles for yield, quality and resilience to biotic and abiotic stresses. Modern approaches including genome sequencing, high-throughput genotyping and advanced phenotyping have accelerated the identification of quantitative trait loci and candidate genes. Breeding programmes now integrate marker-assisted selection, genomic selection and gene editing to enhance disease resistance, tuber quality and adaptability to changing climates. The exploitation of heterotic groups and interspecific introgression is expanding the genetic base of breeding populations, while advances in propagation methods and seed systems ensure rapid dissemination of improved varieties to smallholder farmers worldwide.

Research from Nature Portfolio

A chromosome-scale genome assembly of greater yam (Dioscorea alata) revealed an ancient allotetraploidisation event and extensive genome reorganisation. By integrating a dense genetic map, researchers identified quantitative trait loci for anthracnose resistance and key tuber quality attributes. Analysis of breeding lines uncovered regions of high heterozygosity likely derived from interspecific introgression, offering novel alleles for future improvement. In a study of winged yam (Dioscorea alata) accessions, combined phenotypic and single nucleotide polymorphism data delineated three genetic clusters, enabling the definition of heterotic groups to maximise diversity and heterosis in breeding schemes. Comparative assessment of white Guinea yam (Dioscorea rotundata) germplasm using morphological traits and genome-wide SNP markers demonstrated that joint analysis of phenotypic and molecular data provides the most comprehensive insight into genetic relationships for parental selection.

Genetic Diversity and Improvement of Tuber Crops publication trend

The graph below shows the total number of articles in genetic diversity and improvement of tuber crops 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 quantitative trait.

Single nucleotide polymorphism (SNP): A single base-pair change in the DNA sequence, used as a genetic marker.

Genome assembly: The reconstruction of the full DNA sequence of an organism’s genome from sequencing data.

Heterozygosity: The presence of different alleles at a particular gene locus within an individual’s genome.

Marker-assisted selection (MAS): A breeding approach using molecular markers to select individuals carrying desirable alleles.

Genomic selection: A method that uses genome-wide marker information to predict the breeding value of individuals for complex traits.

References

1. Chromosome evolution and the genetic basis of agronomically important traits in greater yam. Nature Communications (2022).
2. Phenotypic and molecular assessment of genetic structure and diversity in a panel of winged yam (Dioscorea alata) clones and cultivars. Scientific Reports (2019).
3. Comparative assessment of genetic diversity matrices and clustering methods in white Guinea yam (Dioscorea rotundata) based on morphological and molecular markers. Scientific Reports (2020).
4. Variability and genetic merits of white Guinea yam landraces in Nigeria. Frontiers in Plant Science (2023).
5. Agronomic performance and consumer acceptability of improved water yam (Dioscorea alata L.) varieties in the Republic of Benin. Journal of Agriculture and Food Research (2024).
6. Association mapping in multiple yam species (Dioscorea spp.) of quantitative trait loci for yield-related traits. BMC Plant Biology (2023).