Genetic diversity in North American Cercis Canadensis reveals an ancient population bottleneck that originated after the last glacial maximum

Abstract

Understanding of the present-day genetic diversity, population structure, and evolutionary history of tree species can inform resource management and conservation activities, including response to pressures presented by a changing climate. Cercis canadensis (Eastern Redbud) is an economically valuable understory tree species native to the United States (U.S.) that is also important for forest ecosystem and wildlife health. Here, we document and explain the population genetics and evolutionary history of this deciduous tree species across its distributed range. In this study, we used twelve microsatellite markers to investigate 691 wild-type trees sampled at 74 collection sites from 23 Eastern U.S. states. High genetic diversity and limited gene flow were revealed in wild, natural stands of C. canadensis with populations that are explained by two major genetic clusters. These findings indicate that an ancient population bottleneck occurred coinciding with the last glacial maximum (LGM) in North America. The structure in current populations likely originated from an ancient population in the eastern U.S. that survived LGM and then later diverged into two contemporary clusters. Data suggests that populations have expanded since the last glaciation event from one into several post-glacial refugia that now occupy this species’ current geographic range. Our enhanced understanding benchmarks the genetic variation preserved within this species and can direct future efforts in conservation, and resource utilization of adaptively resilient populations that present the greatest genetic and structural diversity.

Microsatellite Loci Reveal High Genetic Diversity, Mutation, and Migration Rates as Invasion Drivers of Callery Pear (Pyrus calleryana) in the Southeastern United States

“…The DIYABC inferences add information about how P. calleryana could overcome the limitations imposed by the self-incompatibility and the founder effect. We observed a very high mutation rate for P. calleryana , compared with other species occupying similar ecological niches ( Nowicki et al, 2020 ; Ony et al, 2020 ; Ony et al, 2021 ). This feature, in addition to high gene flow, could contribute to the observed heterozygosity and to increasing the population differentiation under the presence of barriers.…”

New insights into polyploid evolution and dynamic nature of Ludwigia section Isnardia (Onagraceae)

“…Woodruff et al 1981 ; Zubakov and Borzenkova 1990 ; Groot 1991 ) or habitat destruction (e.g. Vargas-Rodriguez et al 2015 ; Mohn et al 2021 ; Ony et al 2021 ). The three Isnardia taxa may also reduce their population sizes under such environmental disturbances.…”

The impact of geography and climate on the population structure and local adaptation in a wild bee

“…For example, in eastern redbud Cercis canadensis population, differentiation occurs along the Appalachian Mountains (Ony et al, 2021), a genetic split comparable to that exhibited by X. virginica. It is probable that other pollinator species have followed similar recolonization routes.…”