Genetic mapping of SSR sequences isolated from wheat genomic DNA libraries.

摘要

During the first step of the wheat Genoplante program, 963 primers pairs were developed using the wheat diploid ancestors : T. monococcum ssp urartu (AA), Aegilops speltoides (BB) and T. tauschii (DD), leading to a general genome coverage of 80%. Three new enriched libraries were produced using T. durum cv Langdon, T. aesfivum cv Renan and T. tauschii as source of DNA in order to increase the coverage with SSR markers. A total of 8105 clones were sequenced (2067, 4417, 1621 respectively for each library) and the redundancy within the libraries was evaluated (59%, 56% and 48% respectively).The best results regarding polymorphism were observed with T. aestivum cv Renan (67%), T. monococcum ssp urartu (64%), and T. tauschii (60%). Lower results were obtained with T. durum cv Langdon (56%) and Aegilops speltoides (40%). On the other hand, 471 SSR were developed from EST sequences and low copy genomic sequences leading to a total of 2315 useful SSRs, 864 of them being already mapped. We obtained a SSR Genoplante ITMI map which covers now 92% of the genome and provides a precious tool for QTL analysis, description and analysis of genetic resources and the cloning of genes of interest. It would be now useful to realise an anchor map using SSRs only and to develop links between genetic and physical maps.