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.
|Original language||English (US)|
|State||Published - Dec 2021|
Bibliographical noteFunding Information:
This work was supported, in part, by the United States Department of Agriculture (USDA; Grant 58‐6062‐6), the USDA National Institute of Food and Agriculture (NIFA; Hatch project 1009630: TEN00495), and the University of Tennessee’s Open Publishing Support Fund. We are extremely grateful for the enthusiastic sampling help of more than 52 individual contributors, friends, and family who assisted us by gathering leaf tissue samples and collection coordinates for wild growing redbud trees across the U.S. Without each of your support, this effort would not have been possible. Also, we are sincerely thankful to Adrienne Gorny (Cornell University), David Held (Auburn University), Caterina Villari and Megan Buland (University of Georgia), Chris Wyman (University of Tennessee), Christine Nalepa and John Banask (North Carolina Department of Agriculture & Consumer Services), Cory Tanner (Clemson University), Donn Johnson and Lizabeth Herrera (University of Arkansas), Erfan Vafaie (Texas A&M University), Eric Day (Virginia Tech), Eric Rebek (Oklahoma State University), Erin Pfar (Rutgers University), Frank Hale (University of Tennessee), Gary Bachman (Mississippi State University), Grace Pietsch (University of Tennessee), Jackie Lee (University of Arkansas), Jason Griffin (Kansas State University), Juang-Horng Chong (Clemson University), John Olive (Auburn University), Katherine Kilbourne (Tennessee Department of Agriculture), Matt Ginzel and Geoffrey Williams (Purdue University), Michelle Clayson (Michigan, US), Natalie Diesel and Robbie Doerhoff (Missouri Department of Conservation), Nathan Schiff (United States Department of Agriculture, Mississippi), Philip Marshal (Vallonia State Nursery, Indiana), Raymond Moore (Tennessee Valley Authority, Alabama), Rob Pivar (University of Tennessee), Ron Winston (Florida), Sandra Wilson (University of Florida), Sarah White (Clemson University), Scott Goldman (Tennessee Department of Agriculture), Scott Ludwig (Amvac Chemical Corp., Texas), Shimat Joseph (University of Georgia), Stephen Clarke, Mr. Horne, Ms. Standard, and Mr. Gras (United States Department of Agriculture-Forest Service, Texas), Steve Meyers (Mississippi State University), Sydney Everhart and Eldon Everhart (University of Nebraska-Lincoln), and Will Hudson (University of Georgia).
© 2021, The Author(s).