In-situ characterization of wild Annona squamosa L. genotypes reveals rich genetic diversity and elite selections for crop improvement and conservation

The underutilized fruit crop Sugar apple (Annona squamosa L.) holds significant potential for genetic improvement owing to its diverse agro-morphological and biochemical traits. In the present study, 70 wild and semi-wild genotypes from the Eastern Plateau region of India were evaluated and characterized in situ to assess their trait diversity, phenotypic variability, and selection potential. A comprehensive evaluation revealed wide variation in plant and fruit characteristics. Green fruit exocarp colour with cordate fruit shape, impressed fruit surface and creamy white pulp colour were recorded as dominant fruit traits. The Fruit weight, pulp per cent, and seed number ranged from 70.67 to 216.00 g, 41.14 to 77.48% and 5.52 to 36.28 seeds/fruit, respectively, with several genotypes outperforming the commercial cultivar, Arka Sahan. Biochemical profiling showed considerable diversity in SSC (12.60- 29.37o Brix), sugars (10.82–27.77%), titratable acidity (0.26–0.67%), ascorbic acid content (12.60–39.84 mg/100 g) and total phenols content (86–139.97 mg GAE/100 g), with antioxidant activity ranging from 72.53 to 164.36 mg AEAC/100 g among the sugar apple diversity in the region. The fraction of phenolics was studied using UHPLC, and the results showed that gallic acid was the dominant phenolic compound, followed by p-coumaric acid, vanillic acid, chlorogenic acid, protocatechuic acid, 4-hydroxybenzoic acid, ferulic acid and syringic acid. Principal component analysis (PCA) explained over 81% of the cumulative variation, and hierarchical clustering grouped the genotypes into five major clusters, indicating distinct phenotypic diversity. The Multi-Trait Genotype–Ideotype Distance Index (MGIDI) effectively identified 12 elite genotypes with superior trait combinations, reinforcing its utility in perennial crop selection. These findings underscore the diversity of wild sugar apple populations and provide a valuable foundation for targeted breeding, conservation, and cultivar development strategies.