Biology subjects

Hathorn, A.

Publications and source records attributed to Hathorn, A..

3 recordsLinked to original sources

bioRxiv2025

Scaling up orphan crop research: A global genetic perspective of cowpea (Vigna unguiculata) diversity from 10,617 accessions

Cowpea (Vigna unguiculata L. Walp) is a dryland legume crop, providing essential food and nutritional security for millions of people across the semi-arid tropics, in Africa, Asia, and Latin America. However, as a typical "orphan crop", cowpea has long remained underrepresented in global genomic research to support crop improvement. Here, we conducted the largest genetic diversity analysis of cowpea to date, comprising 10,617 accessions sourced from seven international collections. Using genotyping-by-sequencing, we characterized the global patterns of genetic diversity, assessed redundancy within and across collections, and examined the geographic structure of the cowpea global allele pool. Our results revealed nine distinct genetic groups with clear geographic associations and fine-scale population differentiation, reflecting dispersal history, regional adaptation and the influence of modern breeding. Duplication across collections was detected, highlighting the need for improved curation and integration of germplasm resources. Landraces from sub-Saharan Africa do not fully capture the genetic diversity present in several other geographic regions, indicating the existence of abundant and untapped genetic resources worldwide. These findings not only provide insights into the genetic structure and evolutionary history of cowpea but also offer a valuable foundation for harnessing global germplasm diversity to enhance breeding potential and accelerate crop improvement.

plant biology↗

bioRxiv2022

Genetic diversity analysis and characterization of Ugandan sorghum

The National Genebank of Uganda houses diverse and rich Sorghum bicolor germplasm collection. This genetic diversity resource is untapped, under-utilized and has not been systematically incorporated into sorghum breeding programs. In this study, we characterized the germplasm collection using whole genome SNP markers. Discriminant analysis of principal components (DAPC) was implemented to study racial ancestry of the accessions in comparison to a global sorghum diversity set and characterize sub-groups and admixture in the Ugandan germplasm. Genetic structure and phylogenetic analysis was conducted to identify distinct genotypes in the Ugandan collection and relationships among groups. Furthermore, in a case study for identification of potentially useful adaptive trait variation for breeding, we performed genome-wide association studies for juvenile cold tolerance. Genomic regions potentially involved in adaptation of Ugandan sorghum varieties to cooler climatic conditions were identified that could be of interest for expansion of sorghum production into temperate latitudes. The study demonstrates how genebank genomics can potentially facilitate effective and efficient usage of valuable, untapped germplasm collections for agronomic trait evaluation and subsequent allele mining.

plant biology↗

bioRxiv2019

Large-scale GWAS in sorghum reveals common genetic control of grain size among cereals

O_LIGrain size is a key yield component of cereal crops and a major quality attribute. It is determined by a genotypes genetic potential and its capacity to fill the grains.\nC_LIO_LIThis study aims to dissect the genetic architecture of grain size in sorghum via an integrated genome wide association study (GWAS) using a diversity panel of 837 individuals and a BC-NAM population of 1,421 individuals.\nC_LIO_LIIn order to isolate genetic effects associated with grain size, rather than the genotypes capacity to fill grain, a field treatment of removing half of the panicle during flowering was imposed. Extensive variation in grain size with high heritability was observed in both populations across 5 field trials. Subsequent GWAS analyses uncovered 92 grain size QTL, which were significantly enriched for orthologues of known grain size genes in rice and maize. Significant overlap between the 92 QTL and grain size QTL in rice and maize was also found, supporting common genetic control of this trait among cereals. Further analysis found grain size genes with opposite effect on grain number were less likely to overlap with the grain size QTL from this study, indicating the treatment facilitated identification of genetic regions related to the genetic potential of grain size rather than the capacity to fill the grain.\nC_LIO_LIThese results enhance understanding of the genetic architecture of grain size in cereal, and pave the way for exploration of underlying molecular mechanisms in cereal crops and manipulation of this trait in breeding practices.\nC_LI

genetics↗