Analysis of genetic diversity among papaya cultivars using Single Primer Amplification Reaction (SPAR) methods

Abstract

SummaryThree different Single-Primer Amplification Reaction (SPAR) methods namely, Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR) and Directed Amplification of Minisatellite DNA (DAMD) were used to measure genetic diversity among ten commercially important Indian papaya cultivars. Eighteen, 7 or 2 primers were used in each method to amplify a total of 134, 74 and 21 distinct fragments, respectively. Of these, approximately 51%, 61% and 57% of the bands were polymorphic in each case. Genetic distances were measured separately by each method for pairs of papaya cultivars and the results depicted graphically as Neighbor Joining (NJ) trees.The three methods revealed different groupings of the ten cultivars.A NJ tree based on the cumulative data from all three methods correlated with a grouping of the cultivars on the basis of fruit pulp colour and plant height. On the basis of the highest number of polymorphic bands observed (61%), ISSR-PCR was judged to be the best method for analysing all papaya germplasm tested.