Development of microsatellite markers for wheat genetic mapping improvement: outcomes from the wheat Genoplante program.

 

Pierre SOURDILLE1, *, Béatrice GANDON1, 2, Nathalie NICOT1, Vincent CHIQUET1, 2, Liyi Zhang1, Sébastien SPECEL2, Nathalie FOISSET2, Philippe DUFOUR2, Alain MURIGNEUX2 and Michel BERNARD1

 

Addresses :

1 UMR INRA-UBP Amélioration et Santé des Plantes, Domaine de Crouelle, 234 Avenue du Brézet, 63100 CLERMONT FERRAND, FRANCE

2 BIOGEMMA, Campus Universitaire des Cézeaux, 24, Avenue des Landais, 63170 AUBIERE, FRANCE

* Corresponding author: (33) 4 73 62 44 37, pierre.sourdille@clermont.inra.fr

 

ABSTRACT

 

Microsatellites have shown their great efficiency for wheat genetic mapping and for establishment of saturated linkage maps on every agronomical cross of interest. In this project, six microsatellite enriched libraries were produced using as DNA source the wheat diploid ancestors T. urartu, Ae. speltoides and T. tauschii (two libraries) or polyploid wheats like T. durum cv Langdon and T. aestivum cv Renan. More than ten thousand of genomic clones were sequenced on both sides (21,037 sequences) and analyzed for redundancy leading to 5,593 contigs. Primer pairs could have been design for 40% of them. More than 80% of the primer pairs gave an amplification product and about 60% of them were polymorphic on a set of eight wheat lines and mapped (1,101 loci). Simultaneously, genomic low copy and EST sequences were screened for the presence of a microsatellite motifs. About 10% of the EST contigs contained a SSR and a set of 1,497 primer pairs was designed and evaluated for polymorphism on the same eight varieties. The level of polymorphism was lower compare to the genomic SSRs (40%) but the profiles were of better quality. Overall, about 1,700 new loci were mapped during this program. Together with the public SSRs, the coverage is now of about 1 SSR each 1.5 cM. Linking this SSR genetic map with the cytogenetical map will provide a powerful tool for molecular cloning of genes of agronomical interest.