Proceedings of the XLV Italian Society of Agricultural Genetics - SIGA Annual Congress

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

CAPS - ASSISTED SELECTION OF BC TOMATO HYBRIDS FOR RESISTANCE TO TSWV

LANGELLA R.*, ERCOLANO M.R.*, COZZOLINO A.*, BARONE A.**

* Dept. of Agronomy and Plant Genetics, Via Univesità 100, 80055 Portici, Italy;

** Research Institute for Vegetable and Ornamental Plant Breeding, IMOF/CNR, Via Università 133, 80055 Portici Italy

ambarone@unina.it

tomato, resistance to TSWV, backcross, molecular marker assisted selection

During last years an increased incidence of Tomato Spotted Wilt Virus (TSWV) in tomato field of temperate areas has been observed. TSWV infection reduces yield and fruit with necrotic and clorotic ringspot become unmarketable. Resistance against TSWV was found in the tomato cv. Stevens. This resistance is due to a single dominant gene (Sw-5) originated from L. peruvianum and located on the long arm of chromosome 9 (Stevens et al., 1995 Theor Appl Genet 90:451-456).

Some molecular markers linked to this gene have been found and a marker assisted selection project started two years ago to introgress this resistance gene in tomato lines previously selected for good processing quality (Ercolano et al., 1999-Atti XLIII Convegno Annuale SIGA).

A CAPS marker, has been used to select resistant genotypes in different backcross generations obtained by crossing the cv. Stevens with 2 cultivated lines, Poly 39 and ADVF. In each backcross generation the selection of resistant genotypes was performed testing the molecular marker on at least 20 genotypes.

In particular, F₁BC₅ generations have been obtained backcrossing Stevens with these two lines, and F₂BC₅ seed is also available from the resistant genotypes. These plants will be tested in the fields in order to select the resistant genotypes which also exhibit the best agronomic performances.

Furthermore, other backcross breeding schemes were performed in order to enhance the number of varieties resistant to TSWV, and 4 F₁BC₂ progenies have been obtained from tomato lines for processing 141, PI15250, Poly A and Sel 8.