Comparative mapping in the Rosoideae tribe: Fragaria and Rosa.
Résumé
A comparative mapping study has been done among two closely related genera in the Rosoideaetribe. Our objective was to use a common set of markersto show macrosynteny and macrocolinearity across the two generaFragaria(strawberry:2n=2x= 14) and Rosa (rose:2n=2x= 14). We used anonymous SSRs derived from a genomic library (55 primer pairs fromF. x ananassa) and from Expressed Sequence Tag (70 new primer pairs derived from Rosa(30), F.vesca (18 )and F.x ananassa (22) ESTs). In addition, we have tested 24 primer pairs derived from gene sequences involved in Rosa floral initiation. The anonymous SSRs and the SSR-ESTwere tested on denaturating polyacrylamide gel with silver staining. On the total of 125 primer pairs, only twelve (10%) were polymorphic in both populations. In order to reveal more polymorphism, we tested all primers pairs derived from ESTs with the Single-Strainded Conformation Polymorphism approach. Using this technique, more polymorphic SSRs were detected. Furthermore, primer pairs derived from floral initiation gene sequences in Rosawere tested on SSCP and 25 % were polymorphic in both populations. At thistime, 24 markers will provide anchor points to link the 7 homologous linkage groups .In order to have a true comparison of the homologous linkage groups, we shall verify the orthology of alleles by sequencing them. This comparative mapping study will provide useful information regarding the evolution of the two genomes.