Genomic and transcriptomic approaches towards the genetic improvement of an underutilised crops: The case of Bambara groundnut

Abstract

With the world population estimated to be nine billion by 2050, the need to exploit plant genetic diversity in order to increase and diversify global food supply, and minimise the over-reliance for food on a few staple crops is of the utmost importance. Bambara groundnut (Vigna subterranea (L) Verdc.), is underutilised legume indigenous to Africa, rich in carbohydrates, with reasonable amounts of protein. It is known to be drought tolerant, able to grow on marginal lands where other major crops cannot with minimal rainfall (<700 mm) and chemical inputs. Crop improvement for abiotic stress tolerance and increasing/stabilising yield have been difficult to achieve due to the complex nature of these stresses, and the genotype x environment interaction (GxE). This review paper highlights how a number of recent technologies and approaches used for major crop research, can be translated into use in research of minor crops, using bambara groundnut as an exemplar species. Using drought tolerance as a trait of interest in this crop, we will demonstrate how limitations can affect genomic approaches for understanding traits in bambara groundnut, and, how genomic and transcriptomic methodologies developed for major crops can be applied to underutilised crops for better understanding of the genetics governing important agronomic traits. Furthermore, such approaches will allow for cross species comparison between major and minor crops, exemplified by bambara groundnut leading to improved research in such crops. This will lead to a better understanding of the role of stress-responsive genes and drought adaptation in this underutilised legume.