Morphological and antioxidant characteristics of mulberry (Morus spp.) genotypes

Abstract

Mulberry is a multipurpose tree, which can be utilized for catering diversified needs such as food, fodder, fuel and fibre. It has earned ‘superfood’ status, in European countries, owing to presence of bioactive compounds in fruits. In India, mulberry is considered an underutilized fruit crop and the breeding efforts on mulberries made so far were restricted to development of genotypes suitable for sericulture. However promising selections of mulberry, intended for commercial fruit production, have recently been made. Therefore, an investigation about the phytochemical constituents of available promising mulberry genotypes could help develop an improved understanding and appreciation of the nutraceutical and medicinal value of this fruit, which consequently will promote its consumption in society. In the present investigation, we assessed variations in morphological characteristics, phytochemical and antioxidant capacity among 10 selected mulberry genotypes belonging to 3 mulberry species (Morus alba, M. rubra and M. laevigata). The antioxidant capacity was estimated by CUPRAC, FRAP and DPPH assays. The ascorbic acid content varied from 6.8 to 27.1 mg 100 g−1, total polyphenols from 0.51 to 1.58 mg g−1, total flavonoids from 0.37 to 1.26 mg g−1 and O-dihydric phenol from 0.14 to 0.33 mg g−1 fresh weight. The average antioxidant activities were 3.02–6.92 and 2.79–5.70 µM TE g−1 as determined by the CUPRAC and FRAP assays, respectively. Likewise, according to the results obtained, genotype Delhi Local was found to exhibit the strongest DPPH free-radical scavenging activity followed by Thar Lohit. The results of the study showed that the dark red-fruited mulberry ‘Delhi Local’ with higher antioxidant potential appears to be promising for further commercial exploitation. Keywords: Morphological characterization, Phyllotaxy, Heterophylly, Anthocyanin, CUPRAC, FRAP, Principal component analysis