Genetic diversity of cultivated and wild tomatoes revealed by morphological traits and SSR markers

Abstract

ABSTRACT. In the current study, morphological traits and molecular markers were used to assess the genetic diversity of 29 cultivated tomatoes, 14 wild tomatoes and seven introgression lines. The three components of the principal component analysis (PCA) explained 78.54% of the total morphological variation in the 50 tomato genotypes assessed. Based on these morphological traits, a three-dimensional PCA plot separated the 50 genotypes into distinct groups, and a dendrogram divided them into six clusters. Fifteen polymorphic genomic simplesequence repeat (genomic-SSR) and 13 polymorphic expressed sequence tag-derived SSR (EST-SSR) markers amplified 1115 and 780 clear fragments, respectively. Genomic-SSRs detected a total of 64 alleles, with a mean of 4 alleles per primer, while EST-SSRs detected 52 alleles, with a mean of 4 alleles per primer. The polymorphism information content was slightly higher in genomic-SSRs (0.49) than in EST-SSRs (0.45). The mean similarity coefficient among the wild tomatoes was lower than the mean similarity coefficient among the cultivated tomatoes. The dendrogram based on genetic distance 13869 Genetic diversity analysis of cultivated and wild tomatoes ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 13868-13879 (2015) divided the 50 tomato genotypes into eight clusters. The Mantel test between genomic-SSR and EST-SSR matrices revealed a good correlation, whereas the morphological matrices and the molecular matrices were weakly correlated. We confirm the applicability of EST-SSRs in analyzing genetic diversity among cultivated and wild tomatoes. High variability of the 50 tomato genotypes was observed at the morphological and molecular level, indicating valuable tomato germplasm, especially in the wild tomatoes, which could be used for further genetic studies.

Use of microsatellites for evaluation of genetic diversity in cherry tomato

“…Zhou et al (2015a) evaluated a total of 29 cultivated tomatoes (S. lycopersicum), 14 wild tomatoes, and 7 introgression lines (ILs) developed from a cross between S. pennellii and S. lycopersicum with 9 morphological traits and 15 genomic-SSR and 13 EST-SSR primers. Zhou et al (2015b) compared the genomic simple sequence repeat (gSSR) and EST-derived SSR (EST-SSR) markers when analyzing genetic variability of 48 tomato cultivars from different countries.…”

Assessment of Genetic Diversity in Cultivated Tomato (Solanum lycopersicon L.) Genotypes using Molecular Markers

“…Shah et al, (2013), Benor et al, (2008) Zhou et al, (2015) and Korir et al, (2014) also reported similar results while studying the PIC of genomic SSRs and ESTT-SSR markers in various tomato lines. In the present study, SSR and RAPD markers detected medium locus polymorphism among the 24 tomato genotypes, indicating that both markers are of great utility for genetic diversity studies of tomatoes and can further be utilized in strengthening tomato breeding programmes.…”

Evaluation of Genetic Diversity by DNA Barcoding of Local Tomato Populations from North-Western Romania

“…Domestication of tomatoes by selecting preferred traits has led to low genetic diversity among cultivated tomatoes. A high similarity coefficient was found among 29 cultivated tomatoes using SSR markers, as published by Zhou et al, 2015. In 2011 three DNA markers to distinguish 26 tomato varieties, and found that nrDNA ITS region and rDNA 5S showed high nucleotide variation, whereas cpDNArbcL region was not suitable for tomato variety identification.…”