Variability in Catechin and Rutin Contents and Their Antioxidant Potential in Diverse Apple Genotypes.

Catechins and rutin are among the main metabolites found in apple fruit. Sixty apple genotypes, harvested in 2016 and 2017, were analyzed for their phenolic content and antioxidant activity. The HPLC analysis showed that the catechin concentration ranged from 109.98 to 5290.47 µg/g, and the rutin concentration ranged from 12.136 to 483.89 µg/g of apple fruit. The level of DPPH activity ranged from 9.04% to 77.57%, and almost half of the 15 genotypes showed below 30⁻40% DPPH activity. The apple genotypes 'Lal Ambri', 'Green Sleeves', and 'Mallus floribunda' showed the highest DPPH activity of between 70% and 80%, while 'Schlomit', 'Luxtons Fortune', 'Mayaan', 'Ananas Retrine', and 'Chaubatia ambrose' showed the lowest ferric reducing antioxidant power (FRAP) activity (0.02⁻0.09%). Statistical analysis showed a correlation between DPPH activity and catechin content (r = 0.7348) and rutin content (r = 0.1442). Regarding antioxidant activity, fractionated samples of apple genotypes revealed significant activity comparable to that of ascorbic acid. There was also a consistent trend for FRAP activity among all apple genotypes and a significant positive correlation between FRAP activity and rutin content (r = 0.244). Thus, this study reveals a significant variation in antioxidant potential among apple genotypes. This data could be useful for the development of new apple varieties with added phytochemicals by conventional and modern breeders.

SSR and RAPD analysis of genetic diversity in walnut (Juglans regia L.) genotypes from Jammu and Kashmir, India.

In this study, the genetic relatedness of 82 walnut genotypes adapted to the North Western Himalayan region of Jammu and Kashmir, India was analyzed by combination of 13 SSR and 20 RAPD primers. A high level of genetic diversity was observed within populations with the number of alleles per locus ranging from one to five in case of SSR primers and two to six in case of RAPD primers, the proportion of polymorphic loci was 100 %, and similarity ranged from 12 % to 79 % with an average of 49 %. Dendrogram showed that all the accessions formed four main clusters with various degree of sub-clustering within the clusters. These results have implications for walnut breeding and conservation.