Population structure, landscape genomics, and genetic signatures of adaptation to exotic disease pressure in Cornus florida L. – insights from GWAS and GBS data

Understanding the consequences of exotic diseases on native forests is important to evolutionary ecology and conservation biology because exotic pathogens have drastically altered US eastern deciduous forests. Cornus florida L. (flowering dogwood tree) is one such species facing heavy mortality. Characterizing the genetic structure of C. florida populations and identifying the genetic signature of adaptation to dogwood anthracnose (an exotic pathogen responsible for high mortality) remains vital for conservation efforts. By integrating genetic data from genotype-by-sequencing (GBS) of 289 trees across the host species range and distribution of disease, we evaluated the spatial patterns of genetic variation and population genetic structure of C. florida and compared the pattern to the distribution of dogwood anthracnose. Using GWAS and gradient forest analysis, we identified genetic loci under selection and associated with ecological and diseased regions. The results revealed signals of ...