Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: AFLP
            

IDENTIFICATION OF AFLP FRAGMENTS LINKED TO PATHOGEN RESISTANCE GENES AND CONVERSION TO SCAR MARKERS FOR RAPID SCREENING IN TOBACCO BREEDING

Institut du Tabac Groupe ALTADIS, Laboratoire de Biologie Cellulaire et Moléculaire, Domaine de la Tour, 24100 Bergerac, FRANCE

The potential of molecular markers for varietal identification was assessed on different Nicotiana tabacum cultivars. According to a previous study achieved at the Bergerac’s Institut du Tabac, AFLP allowed to get up to 12% polymorphism using 64 primer combinations on three varieties belonging to the three types of commercial tobacco (dark-air-cured, burley and flue-cured). Combinations of the most effective primers have been selected and used to assess the genetic diversity within 97 genotypes of industrial types. Forty two AFLP markers were used to characterize most of these varieties (91/97), and the genetic relationships between these cultivars have been studied by the UPGMA method. Clusters of varieties with common traits have been observed. Interspecific origin of the varieties are widely responsible for the polymorphism observed. In order to identify AFLP markers linked to pathogen resistance genes, a Multiple Correspondance Analysis was achieved. Five candidate markers linked to resistance genes were identified : two for blue mold (Peronospora tabacina) resistance, two for the Va gene (Potato Virus Y) susceptibility and one for resistance to black root rot (Chalara elegans = Thielaviopsis basicola). Some of these markers were sequenced and converted into SCARs markers, with the aim of using them in a breeding program. Powerfulness of AFLP technique has already opened interesting perspectives for obtaining a primary genetic map. It would be a reliable tool for improving traits linked to leaf quality of commercial tobacco.