Caracterização de genótipos de tomateiro resistentes a begomovírus por marcador molecular co-dominante ligado ao gene Ty-1

Abstract

The objectives of this study were to evaluate tomato genotypes for begomovirus resistance and to assess SSR-47 fingerprinting patterns associated with alleles Ty-1, in hybrids of fresh-market tomato with commercial potential. Twenty-four experimental genotypes, heterozygous at Ty-1 locus, were infected with begomovirus via grafting, and showed intermediate symptoms compared to the ones identified by homozygous Ty-1/Ty-1 lines and by susceptible genotypes Ty-1 +/Ty-1 +, which indicates the incomplete dominance of the Ty-1 allele. These hybrids were considered to possess partial resistance to begomovirus. The experimental hybrids TEX-246, TEX-261, TEX-253, TEX-256, TEX-262, TEX-252, TEX-251 and TEX-268 combined high total yields with high mean fruit mass. The hybrids TEX-246, TEX-253, TEX-256, TEX-262 and TEX-252 showed also longer half-life for fruit firmness and were thus considered competitive with current commercial hybrids used as checks. The molecular marker SSR-47 was effective for fingerprinting of tomato genotypes bearing the resistance allele Ty-1. The graft-induced infection of begomovirus showed symptoms in the genotypes tested that are in agreement with the results of fingerprinting with the marker SSR-47. © 2009 Embrapa Informação Tecnológica.