Genetic diversity analysis using SSR markers for high temperature tolerance in tomato (Solanum lycopersicum L.)

Abstract

Molecular characterization of selected 22 tomato genotypes
(Solanum lycopersicum L.) under high temperature stress
condition was assessed using 25 simple sequence repeat
(SSR) markers. Out of the 25 markers used 22 primers showed
amplification, 15 SSRs were monomorphic and 7 were
polymorphic. Polymorphism information content (PIC) value
of the markers ranged from 0.58 to 0.65 with an average
value of 0.6. The highest PIC value was shown by SSR
96(0.65). Phylogenetic tree was constructed based on
Jaccard’s similarity coefficient using the unweighted pairgroup
method with arithmetic mean (UPGMA) using
NTSYSpc cluster analysis software. Cluster analysis divided
the twenty-two genotypes into four clusters. SSR marker
analysis and cluster analysis were able to differentiate the
genotypes into; tolerant, moderately tolerant, susceptible
and genotypes which show mixed characteristics. Genetic
maps currently available in tomatoes have a limited number
of SSR markers that are not uniformly distributed across the
genome, so this study helps our fundamental understanding
in identification of molecular markers linked to high
temperature tolerance in tomato.