Morphological and Microsatellite Analysis of Intravarietal Heterogeneity in 'Beneshan' Mango ( Mangifera indica L.)

'Beneshan' is the choicest table cultivar of mango (Mangifera indica L.) that has been under cultivationfor more than a century in Andhra Pradesh state, India. Through an eco-geographic survey covering thethree regions of the state, 31 accessions of 'Beneshan' (BN Acc-l to BN Acc-31) were selected and theirfruit and leaf samples were collected to study intracultivar heterogeneity based on morphological fruittraits and microsatellite markers, respectively. In-situ characterization and evaluation of fruit samplesrevealed phenotypic variations among 'Beneshan' accessions. Of the 109 mango-specific simple sequencerepeats (SSRs) validated, 23 were polymorphic. Polymorphic microsatellites produced a total of 58alleles, of which 30 were polymorphic (51.72%). The polymorphic information content values variedfrom 0.03 (SSR-59) to 0.72 (SSR-87). Highly polymorphic microsatellites like SSR-80, SSR-87, SSR-28,and SSR-89 were more useful in differentiating the 'Beneshan' accessions. Microsatellites SSR-91 andMngSSR-26 produced unique alleles of 280 and 140 bp in BNAcc-8 and BNAcc-9 accessions,respectively. Jaccard’s similarity coefficient varied from 0.50 to 1.00. There was a wide range ofintravarietal heterogeneity (up to 50%) indicating that 'Beneshan' whatsoever cultivated throughout thestate is not pure clone, which allows the genetic breeding of this cultivar by means of mass selection.