Genetic variation and genotype by environment interaction in Jatropha curcas L. germplasm evaluated in different environments of Cameroon

Jatropha curcas L. (jatropha) is a perennial plant with a high untapped potential towards sustainable production of food and bioenergy. The transformation of jatropha into a competitive crop requires intensive breeding efforts. The objectives of our study were to (i) assess genetic variation of agronomic and quality traits in different environments, (ii) investigate genotype by environment interactions, and (iii) discuss potential selection strategies. Agronomic and quality traits were assessed on 277 jatropha genotypes that were evaluated over three environments in Cameroon. Genetic variation and heritability of agronomic and quality traits showed excellent prospects to select and breed improved cultivars rapidly. Selection for accumulated seed yield over years seems to be the best choice to increase annual seed and oil yield. Seed yield per month might be incorporated in selection indices to improve the efficiency of fruit harvesting. Selection based on a single testing environment was always inferior to the selection based on multiple environments. The magnitude of genotype by environment interaction (GxE) in jatropha is large. Therefore, testing in multiple environments is a requirement to select improved cultivars with local and broad adaptation.