The local jamun biodiversity appears a good opportunity to sustain and maintain agriculture and to support economy in the marginal zone of plateau area having rocky terrains of Jhalawar district. The genetic diversity of jamun is little known in the forest zone of rocky terrains of Jhalawar district in South Eastern Rajasthan state of India. The main objective under present study was to improve the knowledge of polymorphism of jamun (Syzigium cuminii
Skeels.) in the meagerly explored Jhalawar district forest areas by investigating the ontogeny studies, quantitative and qualitative parameters. Ten selected sites were investigated through field measurement for qualitative and quantitative traits mainly from wild habitats. The qualitative and quantitative analysis on fresh jamun fruits were carried out on ten genotypes collected from the natural habitat particularly forest area of Jhalawar district. The present investigations revealed high variability for all the recorded traits confirmed by a wide polymorphism. The most promising genotype in terms of fruit morpho-quality traits were observed in T2
genotype with respect to fruit weight (10.45g), fruit length (3.22 cm), total soluble solids (20.420
brix), total sugars content (15.90%), antioxidant capacity (97.01%) and also to the good ascorbic acid content (45.95 mg/100g) and best taste in terms of organoleptic evaluation with highest score (8.80) with respect to edible acceptance at horticultural maturity supports the T2
genotype better as compared with other genotypes. The results showed a possible important role of jamun fruits due to the high antioxidant value and ascorbic acid content with potential outcome in the Jhalawar district. Looking to the scope of Jamun, farmers would invest in the development of new orchards, addressed to local markets by targeting food nutrition security of the marginal area. The present study demonstrates the ethno-botanical significance of jamun biodiversity for further expansion in the South Eastern districts of Rajasthan comprising Jhalawar, Bundi, Baran, Kota and Sawai Madhopur districts.