Widening the Arachis hypogaea seed chemical composition: the case of a recombinant inbred lines introgressed with genes from three different wild species

Abstract

Peanut (Arachis hypogaea L.) is an important row crop rich in oil, protein, vitamins and other micro-nutrients. The intensive selection of the cultigen, a cultivated plant deliberately altered by humans through cultivation, has resulted in favourable changes in yield and biochemical composition. Nevertheless, it has generated a narrow genetic basis that limits the development of new varieties with resistance to pests, diseases and environmental stresses. In this study, we address this limitation by characterizing the proximate and fatty acid composition of a multi-disease-resistant interspecific recombinant inbred line (RIL) population derived from three wild Arachis species and a cultivated elite peanut line that is being used to widen the genetic basis of the crop. The population was also genotyped with the Axiom Arachis 48K SNP array and used to detect quantitative trait loci (QTL) for oil, protein content and oleic and linoleic fatty acid percentages. A wide range of proximate composition was found in the RIL population. Eighteen and 11 individuals had high oil and protein content, respectively, and no undesirable traits related to oil quality had been introduced into the population from wild species. The fatty acid composition of oleic and linoleic acids was found to be regulated by two major QTL. The discovery of markers within the major effect QTL for the most significant chemical traits provides new opportunities for the creation of resistant and extremely nutrient-dense peanut cultivars.