Profiling Cultivars Development in Kersting's Groundnut [Macrotyloma geocarpum (Harms) Maréchal and Baudet] for Improved Yield, Higher Nutrient Content, and Adaptation to Current and Future Climates

Abstract

Kersting's groundnut [Macrotyloma geocarpum (Harms.) Maréchal and Baudet], Fabaceae, is an important source of protein and essential amino acids. As a grain legume species, it also contributes to improving soil fertility through symbiotic nitrogen fixation. However, the crop is characterized by a relatively low yield (≤500 kg/ha), and limited progress has been made so far, toward the development of high-yielding cultivars that can enhance and sustain its productivity. Recently, there was an increased interest in alleviating the burdens related to Kersting's groundnut (KG) cultivation through the development of improved varieties. Preliminary investigations assembled germplasms from various producing countries. In-depth ethnobotanical studies and insightful investigation on the reproductive biology of the species were undertaken alongside morphological, biochemical, and molecular characterizations. Those studies revealed a narrow genetic base for KG. In addition, the self-pollinating nature of its flowers prevents cross-hybridization and represents a major barrier limiting the broadening of the genetic basis. Therefore, the development of a research pipeline to address the bottlenecks specific to KG is a prerequisite for the successful expansion of the crop. In this paper, we offer an overview of the current state of research on KG and pinpoint the knowledge gaps; we defined and discussed the main steps of breeding for KG' cultivars development; this included (i) developing an integrated genebank, inclusive germplasm, and seed system management; (ii) assessing end-users preferences and possibility for industrial exploitation of the crop; (iii) identifying biotic and abiotic stressors and the genetic control of responsive traits to those factors; (iv) overcoming the cross-pollination challenges in KG to propel the development of hybrids; (v) developing new approaches to create variability and setting adequate cultivars and breeding approaches; (vi) karyotyping and draft genome analysis to accelerate cultivars development and increase genetic gains; and (vii) evaluating the adaptability and stability of cultivars across various ecological regions.

Genotype by environment interaction and stability analysis of three agronomic traits in Kersting's groundnut (Macrotyloma geocarpum) using factor analytic modeling and environmental covariates

“…This finding is not unexpected in our study areas where the late genotypes may challenge the drought stress during maturation. This result is interesting for Kersting's groundnut breeding because early maturity and high yield are key traits identified by farmers for Kersting's groundnut cultivar development (Coulibaly et al., 2020; Coulibaly, Bodjrenou, et al., 2022). Considering the correlation structure among the evaluated traits, a breeder can thus select in one process superior genotypes for multiple traits (Olivoto et al., 2019).…”

“…The same trend was observed in FA biplot analysis showing the efficiency and consistency of these approaches in examining accessions' stability and adaptability across environments. Moreover, high yielding and stable cultivars are targeted products in Kersting's groundnut breeding program (Akohoue et al., 2019; Coulibaly et al., 2020; Coulibaly, Bodjrenou, et al., 2022). However, high GEI variability (>60% of variance explained by the respective factors) was found for YLD in all the environments, indicating that the changes in climate conditions influenced Kersting's groundnut production (Coulibaly, Idohou, et al., 2022).…”