Project Number: 3655-21000-050-06
Project Type: Grant

Start Date: Aug 21, 2008
End Date: Feb 28, 2010

Objective:
To enhance understanding of and access to the genetic diversity in wild and landrace relatives of tomato and potato, and contribute to the same for other euasterid plant species, five objectives are proposed: 1. Document relative diversity in and relationships among a core germplasm set of wild and cultivated tomato and potato species as revealed by DNA sequences of COSII genes. 2. Help orient the utilization of tomato and potato diversity by re-evaluating grouping concepts based on unbiased measures given by COSII markers. 3. Identify and describe putative regions of positive and negative selection throughout tomato and potato genomes and relate these to known domestication loci or mapped phenotypic traits, focusing on COSII markers linked to domestication loci. 4. Facilitate comparative mapping in the Solanaceae by mapping 300 single-copy COSII (to include the 48 above) in potato, lulo, sweet potato, and carrot. 5. Make these data publicly available on the SGN bioinformatics platform (http://sgn.cornell.edu/).

Approach:
Assessment of genetic and allelic diversity and phylogenetic relationships, with 24 COSII (four per linkage group), across 59 individuals to include cultivated and wild tomato and potato species and outgroups, and a nested diversity assessment in tomato and potato. All of the sequencing will be with a single individual per accession except for a nested study inside the S. peruvianum/S. brevicaule study that will use five clones of each of five individuals for five accessions of S. peruvianum and five clones for five individuals of five accessions in the S. brevicaule complex. The USDA will also sequence parents of one potato mapping population for the 420 COSII markers to be placed on the potato linkage map, and the mapping parents of lulo, sweetpotato and carrot to be provided by cooperators, for their inclusion in diversity and phylogenetic assessment. Some of these species will be the same as those used in the potato AFLP and SSR studies as mentioned above for comparative diversity assessments.