Exploring the genetic diversity of Aegle marmelos (L.) Correa populations in India

Bael is an important sub-tropical fruit crop in family Rutaceae that is widely distributed throughout South-East Asia. For local communities, the nutritious composition of its fruits and leaves offers tremendous economic and social possibilities to exploit. However, its underutilized status, as well as man-made threats to its natural habitat, make it imperative to implement concrete strategies for its cultivation and conservation. To fully grasp the ability of this adaptable fruit tree for human health and environmental well-being, it is necessary to characterize the genetic diversity. The goal of this study was to use morphological (13 quantitative traits), biochemical (9 attributes) and molecular (10 SRAP primers) characterization to evaluate 24 bael genotypes from two agroecological zones of India. Fruit and pulp weight ranged from 79.0- to 1478.8 g and 15.0- to 894.3 g with mean values of 448.67 and 233.3 g, respectively. Traits such as fruit, pulp, and seed weight (g), fruit length (cm) and width (cm), number of fruits per tree, number of seeds per fruit, shell weight (g) and shell thickness (mm) recorded highly significant differences. High phenol (11.65-24.38 mg GAE/g fw) and flavonoid (12.32-74.63 mg CE/g fw) content was observed in fruit pulp indicating significant antioxidant potential of this fruit. Several morphological and biochemical characters were found to have significant positive correlations. Principal component analysis revealed that first five components contributed 96.76% to total variation. Hierarchical cluster analysis separated the populations into two distinct clusters, while analysis of molecular variance (AMOVA) using SRAP markers revealed that 70% of the total marker variation was due to interpopulation variance, while 30% was attributed to intrapopulation.