Variations in the total phenolics and antioxidant activities among garden pea (Pisum sativum L.) genotypes differing for maturity duration, seed and flower traits and their association with the yield

Abstract Food legumes cater the basic nutritional requirement of humans by providing the protein, carbohydrate, minerals, and vitamins, along with several secondary metabolites having antioxidant activities. In this investigation, diverse pea genotypes belonging to different maturity groups, flower color, seed-coat color, and seed-shapes were assessed for their total phenolics and total flavonoids contents including antioxidant activities. In addition, these were also evaluated for various horticultural traits. A number of in vitro antioxidant assays including CUPRAC, FRAP, DPPH, and TEAC were compared for their relative antioxidants potential in different pea genotypes. The purple-flowered and dark seed-coat colored genotypes, EC-9485 and VRP-233 were found having highest total phenolics (128 and 104 mg GAE/100 g fw) and total flavonoids contents (45.8 and 36.8 mg CE/100 g fw) respectively, along with strong antioxidant potential, when compared to white-flowered and light seed-coat colored genotypes. However, pod-yield in these two genotypes was recorded low (22.7 g/plant and 69.2 g/plant) attributed mainly due to their lowest pod-weight (2.5 g/pod and 3.4 g/pod), respectively. At genotypic level, total phenolics content was found highly correlated with TEAC ( rG  = 0.987), CUPRAC ( rG  = 0.979) and DPPH ( rG  = 0.976) assays, while negatively correlated with yield per plant ( rG =-0.305). Furthermore, positive correlation between total phenolics, total flavonoids with antioxidant activities indicated that the phenolics including flavonoids as the main component for antioxidant activity in pea genotypes. Principal component analysis (PCA) and UPGMA cluster analysis grouped the genotypes having a strong antioxidant capacity and high yield in distinct clusters. The results will help the breeders to combine both high-yield and high-antioxidant activity traits in a single genotype, thereby help in achieving the long-term goal of ensuring the nutritional security of the consumers.