Genetic and morphological comparisons of lesser celandine (Ficaria verna) invasions suggest regionally widespread sexual reproduction

Abstract

Both asexual and sexual reproduction can provide important keys to the success of invasive species. A species with potential for both is lesser celandine (Ficaria verna), a European native with multiple subspecies that have been introduced in North America as ornamentals and escaped cultivation. Asexual reproduction via bulbils is prolific in many introduced populations of lesser celandine, with sexual reproduction reportedly rare. Although genetic and morphological diversity of European celandine has been studied, few have examined invasive North American populations. We aimed to document introduced genotypic and phenotypic diversity at a regional scale. We first compared sequence-related amplified polymorphism (SRAP) genotypes of 64 individuals collected from Columbus, Cincinnati, and Cleveland, OH. In a second experiment, we phenotyped 129 individuals from the same regions and from Louisville, KY, measuring traits in an outdoor common garden experiment. The SRAP markers were highly polymorphic and revealed surprising genetic differentiation. Genetic and trait variation were both structured across regions, but we also saw high variation within regions. Cleveland populations differed the most genetically and morphologically. Nearly every individual made asexual bulbils, and many individuals that flowered produced expanded achenes. Trait data suggested subspecies verna or ficariiformis occur in these regions. Genetic admixture within regions and within individuals, along with achene expansion, suggests sexual reproduction may be widespread. Sexual and asexual propagules may spread by different vectors, and our resistance analyses indicated water dispersal and habitat availability contribute to genetic structure. These findings suggest that celandine has substantial potential for further spread and evolutionary change.