PHENOTYPIC CHARACTERIZATION AND GENETIC DIVERSITY ANALYSIS OF EGGPLANT (Solanum spp.) GERMPLASM USING SSR MARKER

Abstract

An experiment was carried out with twenty five local and two wild relatives (Solanum sisymbriifolium and S. torvum) of eggplant at the research field and in the Biotechnology Laboratory of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, during October 2015 to June 2016 to investigate the phenotypic characterization and molecular diversity analysis of different local eggplant germplasm and its wild relatives. The morphological study revealed diversified characters among all the genotypes. Variations were observed in color of leaf vein, stem as well as fruit size and shape. Maximum yield per plant was recorded in Salta Begun and it was 9.8 kg. The minimum yield per plant was observed in both the wild species (3.8 kg) as they produced very small fruits. Correlation of yield contributing traits separated all the genotypes into four clusters (A, B, C, and D). Among them cluster D had five genotypes together with the wild species indicated their relatedness. Five well-known SSR primers were used for the molecular characterization of the genotypes. Ten alleles, ranged from 1 to 3 alleles per locus and an average of 2.0 were detected. Among five primers three were able to produce polymorphic bands and the total number of polymorphic bands was five. The highest (2) number of bands was observed in SSR primers EPSSR82 and smSSR01. The Polymorphism Information Content (PIC) of SSR markers ranged from 0.37 (smSSR01) to 0.67 (EPSSRR82) with an average value of PIC = 0.54. Gene diversity ranges from 0.49 (smSSR01) to 0.72 (EPSSR82), with an average value of 0.61. The value of pair-wise comparisons of Nei‟s (1972) genetic distance (D) and identity between varieties was computed from combined data for the five primers, ranged from 0.20 to 1.00, with an average value of 0.60. Multivariate cluster analysis on the basis of Nei‟s genet ic distance and identity revealed that within those 27 genotypes there surely do exist considerable diversity. UPGMA method separated the segregation of 27 genotypes into two major clusters (I and II). From the clusters, wild species Solanum torvum belonged to the sub-cluster (IIb), that revealed its distinct variation from the others. On the other hand, wild species Solanum sisymbriifolium showed a close relatedness by forming the same cluster together with thirteen local eggplant genotypes. This experiment brought a great opportunity for eggplant improvement as the local genotypes had a close relation with the wild species.