A final step of speciation?
Changes in flowering time and their genetic and ecological background within three closely related diploid Hordeum species from Patagonia
When species come into secondary contact after allopatric speciation geneflow could either result in merging of the lineages or hybrids with reduced fitness in comparison to the parental species occur, which means that resources (gametes) are wasted by hybridizing individuals. The evolution of crossing barriers counters hybridization. In Hordeum three diploid perennial species evolved in allopatry but are now sympatrically distributed in Patagonian. Within this project the evolution of prezygotic isolation through changes in flowering time among the three species will be analyzed. We expect to find staggered, short flowering in stands with multiple species, while in stands build by single species flowering should last over a longer time period. This will prevent/reduce cross pollination in sympatric populations. These differences must be reflected by the allelic composition of the flowering time loci in the genomes of the species. In sympatric populations we expect to find few genetic variation at the flowering time loci in species and clear differences in allele composition among species, while genetic diversity in allopatric populations should be higher. Through association studies in common garden experiments and analyses of three flowering time genes in natural populations we will test these hypotheses. In addition this study will provide first information on flowering time genes in perennial grasses of the economical important wheat tribe Triticeae.
Jakob SS, Rodder D, Engler JO, Shaaf S, Ozkan H, Blattner FR, Kilian B (2014). Evolutionary history of wild barley (Hordeum vulgare subsp. spontaneum) analyzed using multilocus sequence data and paleodistribution modeling. Genome Biol Evol 6(3): 685-702, doi: 10.1093/gbe/evu047
Mascher M, Richmond TA, Gerhardt DJ, Himmelbach A, Clissold L, Sampath D, Ayling S, Steuernagel B, Pfeifer M, D'Ascenzo M, Akhunov ED, Hedley PE, Gonzales AM, Morrell PL, Kilian B, Blattner FR, Scholz U, Mayer KF, Flavell AJ, Muehlbauer GJ, Waugh R, Jeddeloh JA, Stein N (2013). Barley whole exome capture: a tool for genomic research in the genus Hordeum and beyond. Plant J 76(3): 494-505