Assessment of genetic diversity of mandarin cultivars grown in major citrus regions of world using morphological and microsatellite markers

Genetic diversity analysis of 46 commercially prominent mandarins grown in different countries was carried out based on molecular and fruit traits. Out of 110 SSR markers, 64 polymorphic markers amplified a total of 155 alleles. Twenty SSR primers revealed 20 unique alleles which generated DNA fingerprints in 17 genotypes. The Polymorphism information content values ranged from 0.13 (CIBE 5156) to 0.73 (CCSM 40), with an average value of 0.45 across all genotypes. The diversity analysis illustrating the genetic relationships classified the genotypes into four major clusters. The 'Nagpur' and 'Mudkhed' mandarins in cluster I were closely related as these showed the highest genetic similarity having a similarity coefficient of 0.99. In fruit traits, higher heritability (h(2)) was observed in fruit weight while the higher genotypic coefficient of variation (GCV) was estimated for a number of seeds demonstrating the magnitude of genetic variability in a population.