Geographic population structure in an outcrossing plant invasion after centuries of cultivation and recent founding events

Abstract

Population structure and genetic diversity of invasions are the result of evolutionary processes such as natural selection, drift and founding events. Some invasions are also molded by specific human activities such as selection for cultivars and intentional introduction of desired phenotypes, which can lead to low genetic diversity in the resulting invasion. We investigated the population structure, diversity and origins of a species with both accidental and intentional introduction histories, as well as long-term selection as a cultivar. Dyer's woad (; Brassicaceae) has been used as a dye source for at least eight centuries in Eurasia, was introduced to eastern USA in the 1600s, and is now considered invasive in the western USA. Our analyses of amplified fragment length polymorphisms (AFLPs) from 645 plants from the USA and Eurasia did not find significantly lower gene diversity () in the invaded compared to the native range. This suggests that even though the species was under cultivation for many centuries, human selection of plants may not have had a strong influence on diversity in the invasion. We did find significantly lower genetic differentiation () in the invasive range but our results still suggested that there are two distinct invasions in the western USA. Our data suggest that these invasions most likely originated from Switzerland, Ukraine and Germany, which correlates with initial biological control agent survey findings. Genetic information on population structure, diversity and origins assists in efforts to control invasive species, and continued combination of ecological and molecular analyses will help bring us closer to sustainable management of plant invasions.

The General Trends of Genetic Diversity Change in Alien Plants’ Invasion

“…The fitness of introduced populations, thus, could be maintained and result in range expansion [ 54 ]. It was reported that except for genetic diversity, the plasticity of IASs was another key factor for tolerance enhancement under environmental pressure [ 32 ]. The high phenotypic plasticity of IASs could enable the invasive population to move toward a new optimal adaptive range despite their low genetic variation [ 55 , 56 ].…”

Understanding the host finding behavior of a biological weed control candidate specialist as a contribution to pre‐release risk assessments

“…Isatis tinctoria is a Eurasian winter annual or biennial mustard that has been repeatedly introduced into North America (hereafter NA) during the early 20th century (Evans & Chase, 1981). It has since naturalized, become invasive, and is now a declared noxious weed in 11 western USA states (Gaskin et al, 2018; USDA NRCS, 2022). Dyer's woad is considered particularly problematic in two distinct geographical areas heavily invaded by the weed in southern Oregon/northern California and in southern Idaho/northern Utah (Gaskin et al, 2018).…”

“…It has since naturalized, become invasive, and is now a declared noxious weed in 11 western USA states (Gaskin et al, 2018; USDA NRCS, 2022). Dyer's woad is considered particularly problematic in two distinct geographical areas heavily invaded by the weed in southern Oregon/northern California and in southern Idaho/northern Utah (Gaskin et al, 2018). The plant has negative impacts on native flora and causes losses in crop and rangeland productivity (Jacobs & Pokorny, 2007).…”

Phylogeny of Davallia (Davalliaceae) from Sumatra and Mentawai Islands, Indonesia: evidence from trnL-F Intergenic Spacer

“…The joining of molecular phylogeny groupings between populations of a Davallia species on Sumatra and Mentawai Islands indicates that those populations are intently related even though these populations are separated via an extensive ocean strait. The unification of these corporations is likely associated with the separation and unification between Sumatra and Mentawai Islands in the past, which allowed one species to revel in a couple of invasions (Gaskin et al 2018). Another elements that also support genetic similarity between Davallia populations in Sumatra and Mentawai Islands is the time of Davallia divergence, taking into consideration the envisioned ages of the crowns and stems, as well as the fossil file in Davalliaceae, so this genus has been isolated from different genera in Davalliaceae for the reason that overdue Miocene (Liu and Schneider 2013).…”