Hide and seek: investigation of biodiversity and distribution of cryptic duckweed species in Alberta

Abstract

This thesis focused on the development of molecular tools to characterize the biogeographical distribution of two cryptic Lemna species suspected to be present in Alberta, Lemna turionifera and L. minor. I developed eight species‐specific primers for five morphologically similar Lemna species. Our preliminary data show L. minor is present in multiple wetlands in southern Alberta. Subsequently, I used genotyping-by-sequencing technology to study the population diversity of these cryptic Lemna species. Based on analyses of 103 samples at 16,007 single nucleotide polymorphism loci, I provide strong support for genetic diversity existing between L. minor and L. turionifera growing in Alberta. I found significant population differentiation in L. minor but no genetically distinct populations within L. turionifera. In summary, DNA barcoding allowed us to exclusively identify unknown specimens to species level. This study provides an example of using next generation sequencing methods to identify significant fine-scale population genetic variations.