Joint analysis of qualitative and molecular diversity provides new insights on the genetic variability of the wild species of tomato (Solanum section lycopersicum) for quality attributes

Abstract

The genetic variability of the tomato (Solanum section lycopersicum) 15 germplasms (seven different species) was assessed using a combination of qualitative and molecular data. The joint dissimilarity matrix showed moderate correlation with the original matrices of quality and molecular data. However, the correlation between the qualitative dissimilarity matrix and the genotypic dissimilarity matrix was low. This finding indicated that molecular markers (ISSR and SSR) did not adequately sample the genomic regions that were relevant for qualitative differentiation of the germplasm. The dissimilarity values of the joint dissimilarity matrix were used to measure qualitative + molecular diversity. This diversity varied from 0 to 1.43 among the 15 germplasm, with an average dissimilarity among genotypes of 0.62. Joint analysis of qualitative and molecular diversity indicated that the genetic diversity of the tomato germplasm was 174% and 69% higher than the diversity estimated from qualitative and molecular data, respectively. These results show that tomato genetic variability is not as limited as previously thought.