Studies on Genetic Variability in Papaya (Carica Papaya L.) Using Rapd and Ssr Markers

Abstract

Studies were conduc~ed to evaluate the genetic diversity of twenty genotypes of Papaya using the RAPD and SSR markers. RAPD analysis with ten primers generated a total of 134 polymorphic bands. The number of amplification products produced by each primer varied from I to 7. Genetic diversity of twenty genotypes in RAPD analysis as estimated by polymorphic information content (PIC) value ranged from 0.60 to 0.99.The cluster dendrogram constructed the basis at RAPD data showed similarity values from 0.64 to 0.97. Dandrogram generated using RAPD data showed two major clusters. Cluster I consist of one genotype however, cluster II included nineteen genotypes. Dendrogram revealed that Pusa Dwarf was distinctly related with PS-I at a similarity coefficient 0.56. SSR analysis generated a total of 84 bands with twenty primers. The number of polymorphic allele ranged from I to 4 with different primers. Out of twenty primers twelve primers s.h owed I 00% polymorphism. Genetic diversity using SSR data as estimated by PIC values ranged from 0.81 to 0.99. The cluster dendrogram of SSR revealed 2 major clusters. Cluster II was the largest and included nineteen genotypes while clusters I comprising of one genotype. Dendrogram generated using SSR data showed that Pusa Dwarf was distinctly related with Pusa Nanha at a similarity coefficient 0.63. Dendrogram of combined analysis revealed 2 major clusters. Cluster II was largest and included nineteen genotypes while, clusters I comprising of one genotype. In current studies SSR primers namely AM903988, AM903848 and mCpCIR I generated higher level of polymorphism and higher level of PIC value. In RAPD primers namely OPL 05, OPC 08 and OPC 03 generated higher level of polymorphism and higher level of PIC value. Hence these RAPD and SSR primers can be efficiently used for estimation of genetic variability in papaya. The information generated from current studies can be used in future breeding programs of papaya improvement for various traits.