The nature of intraspecific and interspecific genome size variation in taxonomically complex eyebrights

Abstract Background and aims Genome size varies considerably across the diversity of plant life. Although genome is, by definition, affected genetic presence/absence variants, which are ubiquitous in population sequencing studies, is often treated as an intrinsic property a species. Here, we studied intra- interspecific variation taxonomically complex British eyebrights (Euphrasia, Orobanchaceae). Our aim to document investigate underlying evolutionary processes shaping between individuals, populations Methods We generated data for 192 individuals diploid tetraploid Euphrasia analysed relation ploidy, taxonomy, affiliation geography. further compared genomic repeat content 30 samples. Key results found considerable intraspecific variation, observed isolation-by-distance outcrossing diploids. Tetraploid showed contrasting patterns, with increasing latitude arctica, but little highly selfing micrantha. Interspecific differences proportions sequences were small. Conclusions show utility treating outcome polygenic variation. Like other types such single nucleotide polymorphisms, may be ongoing hybridization extent subdivision. In addition selection on associated traits, predicted indirectly due pleiotropy variants.