Phenotypic and Molecular-Markers-Based Assessment of Jamun (Syzygium cumini) Genotypes from Pakistan

Abstract

Jamun plant displays enormous diversity throughout Pakistan, which necessitates its screening, evaluation, and validation to document elite genotypes having better traits for the benefit of the fruit industry and farmers. Surveys were made in natural Jamun habitats across Punjab, Pakistan, and genotypes were marked based on visual diversity of trees and fruits. In total, 60 Jamun genotypes were selected for characterization based on phenotypic and genetic markers. Phenotypic characters related to trees, leaf, and flower along with fruit qualitative traits were assessed in situ. Results revealed significant diversity with high (>25%) coefficient of variance values and the first two components of correspondence analysis exhibited 41.71% variation among genotypes. A strong association was observed among traits like upright tree and round fruit shape (0.74), bluish-colored fruit and pinkish pulp (0.85), and elliptic-shaped fruit with low fruit waxiness (−0.72). Leaves of phenotypically characterized plants were brought to Wheat Biotechnology Lab., University of Agriculture, Faisalabad, Pakistan, where Jamun genotypes were investigated genetically using Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. A total of 132 bands were scored, of which 108 were polymorphic, corresponding to almost 81% polymorphism among collected genotypes. High polymorphism information content values were observed against RAPD (0.389) and ISSR (0.457) markers. Genotypes were compared in relation to genetic markers, which exhibited that almost 86% of genetic variability was attributed to differences among accessions, while 14% of variation was due to differences between collections of different areas. Findings of this study confirmed wide phenotypic and genetic distinctness of Jamun in Pakistan that can aid breeders for marker-assisted selection and germplasm enhancement for future crop improvement programs.