Microsatelite marker associated with the Ty-1 allele for resistance to Begomovirus in tomato

Abstract

The objective of this work was to associate a microsatellite marker with the Ty‑1 allele that controls resistance to Begomovirus in tomatoes, and to assess the eficiency of this association in the selection of virus-resistant lines. Microsatellite markers SSR-47 and SSR-48 were tested in near isogenic tomato lines (LA‑3473, LA‑3474, LA‑3475) with contrasting genotypes for the Ty‑1 allele. The marker SSR-47 detected polymorphism in the lines, and was the only one used in the subsequent research phases. An association between the SSR-47 marker and the Ty‑1 locus was detected, and its efficiency for selection of begomovirus‑resistant genotypes in tomato was assessed. To confirm the selection efficiency, plants with contrasting banding patterns for the SSR-47 marker were tested for their reaction to Begomovirus. All plants with a single 191-bp band were resistant to Begomovirus, through inoculation test by grafting. Plants with a single 180‑bp band were susceptible, and plants with both 191bp and 180 bp bands were resistant. The maximum distance between Ty‑1 and the SSR‑47 marker was 2.7 cM. This marker was efficient to identify genotypes bearing the Ty‑1 allele. Plant responses to infection by Begomovirus inoculated through grafting were consistent with reactions predicted with the use of the SSR-47 marker.