Genetic Basis of Local Growing Season Adaptation

I will present work from Genome Wide Association Studies (GWAS) in Arabidopsis thaliana. We show that major QTL control flowering time and depend on local seasonal conditions.  Fall temperature acts as a threshold to convert select overwintering genotypes into rapid cycling under permissive conditions. Across the continental range, flowering time is correlated with population structure, however major QTL show the strongest clinal associations with latitude implicating selection by the environment. At the local landscape scale, genetically diverse populations can be considered as Natural Nested Association Mapping (NNAM) lines where genes for local adaptation can be mapped directly. Finally, simple time lapse imaging was used as high throughput phenotyping to map loci controlling fine growth and development under seasonal conditions.

These tools and methods can be applied in other model plants eg Brachypodium, crops, and foundation species that perform critical ecosystem services.  To this end, methods of Genotyping By Sequencing (GBS) have been established in switchgrass (Panicum virgatum) and are now being applied in Eucalypts and Pelargonia.