Genetic diversity assessment of groundnut (Arachis hypogaea L.) for polyphenol content and antioxidant activity: unlocking the nutritional potential

Groundnut is a rich source of several nutritional components including polyphenols and antioxidants that offer various health benefits. In this regard, the mini core accessions along with elite varieties of groundnut were used to assess genetic diversity using AhTE markers. The phenotypic observation on eight morphological, six productivity and two nutraceutical traits [total polyphenol content (TPC) and total antioxidant activity (AOA)] were studied. Correlation studies revealed a significant positive correlation between TPC and AOA. The degree of divergence with respect to nutraceutical content among the genotypes of mini core collection and elite cultivars is evident from the current study. The STRUCTURE analyses revealed the grouping of genotypes into three distinct clusters mainly based on the botanical types of groundnut. The analysis of molecular variance displayed maximum variation (97%) within the individuals of subpopulations and minimum variation (3%) among subpopulations. Principal component analysis exhibited 3 principal components that accounted for 42.17% of the total variation. Association mapping study indicated 20 significant marker-trait associations at 1% probability. The study has also identified significant marker-trait associations with nutraceutical properties of groundnut, AhTE0465-TPC and AhTE0381- AOA with explained phenotypic variation of 7.45% and 6.85% respectively. These markers were found to have positions at A02 and A09 with bHLH DNA-binding family protein and chitinase putative functions respectively. The markers associated with TPC and AOA can further be utilized for genomics-assisted breeding for nutritionally rich cultivars in groundnut.