| Abstract Detail
Tobacco - Morning van der Hoeven, Rutger [1], Bindler, Gregor [1], Ganal, Martin [2], Plieske, Jorg [2], van der Linden, Gerard [3], Prins, Theo [3], Gadani, Ferruccio [1], Donini, Paolo [4]. The evolutionary origin of Nicotiana tabacum as revealed by SSR and SNP marker development for a genetic map. NICOTIANA tabacum L., an amphidiploid species (2n = 48), is hypothesized to be derived from a hybridization event between Nicotiana sylvestris Spegazzini and Comes, and Nicotiana tomentosiformis Goodspeed. We have previously reported on the construction of a genetic map for tobacco using Simple Sequence Repeat markers (SSRs). In that effort, SSRs were tested for the presence of polymorphisms on a panel of 16 tobacco varieties. A subset of SSR markers was also tested on the two ancestral species. SSR marker data allowed for each of the 24 linkage groups to determine whether those were derived from either N. sylvestris or N. tomentosiformis, or were a product of a translocation event. A separate effort was launched to assess SNP diversity in tobacco genes. For a number of genes, amplicons of ca. 500 bp were sequenced on a panel of 6 N. tabacum varieties, as well as the two ancestral species. The SNP sequencing study revealed additional interesting clues regarding the evolutionary origin of tobacco. Sequence divergence between homologs of N. sylvestris and N. tomentosiformis was substantial, and the same polymorphisms were present in the ancestrally derived homeologs in N. tabacum. However, sequence divergence between homologous genes in tobacco varieties was very low, confirming published data indicating that the hybridization event between N. sylvestris and N. tomentosiformis could be very recent, possibly between 10,000 to 20,000 years ago. In addition, a consistent but low level of polymorphisms between the ancestral genes in N. sylvestris and N. tomentosiformis and the corresponding derived homologs in N. tabacum was found. This indicates that the tested accessions of N. sylvestris and N. tomentosiformis differ from the original parents of the hybridization event, and that these accessions that have found their way into Nicotiana germplasm collections are simply members of a larger species-specific gene pool
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1 - Philip Morris International, Research and Development Department, Neuchâtel, CH-2000, Switzerland
2 - TraitGenetics GmbH, Am Schwabeplan 1b, Gatersleben, 06466, Germany
3 - Plant Research International, Wageningen, 6708 PB, The Netherlands
4 - Philip Morris International R&D, Philip Morris Products SA, Neuchatel, 2000, Switzerland
Keywords:
Nicotiana tabacum
Genome evolution.
Session: Poster-56
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:140 |
