Jeremy S Johnson1, Keith D Gaddis2, David M Cairns2, Kranti Konganti3, Konstantin V Krutovsky4,5,6,7. 1. Department of Geography, Texas A&M University, 810 Eller O&M Building, MS 3147 TAMU, College Station, Texas 77843-3147 USA jsjohnson@tamu.edu. 2. Department of Geography, Texas A&M University, 810 Eller O&M Building, MS 3147 TAMU, College Station, Texas 77843-3147 USA. 3. Texas A&M Institute for Genome Sciences and Society, Texas A&M University Veterinary Medical Research Building, MS 2470 TAMU, College Station, Texas 77433-2470 USA. 4. Department of Forest Genetics and Tree Breeding, Georg-August University of Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany. 5. Department of Ecosystem Science & Management, Texas A&M University, 305 Horticulture and Forest Science Building, MS 2138 TAMU, College Station, Texas 77843-2138 USA. 6. N. I. Vavilov Institute of General Genetics, Russian Academy of Sciences, 3 Gubkina Str., Moscow 119333, Russia. 7. Genome Research and Education Center, Siberian Federal University, 50a/2 Akademgorodok, Krasnoyarsk 660036, Russia.
Abstract
PREMISE OF THE STUDY: Untangling alternative historic dispersal pathways in long-lived tree species is critical to better understand how temperate tree species may respond to climatic change. However, disentangling these alternative pathways is often difficult. Emerging genomic technologies and landscape genetics techniques improve our ability to assess these pathways in natural systems. We address the question to what degree have microrefugial patches and long-distance dispersal been responsible for the colonization of mountain hemlock (Tsuga mertensiana) on the Alaskan Kenai Peninsula. METHODS: We used double-digest restriction-associated DNA sequencing (ddRADseq) to identify genetic variants across eight mountain hemlock sample sites on the Kenai Peninsula, Alaska. We assessed genetic diversity and linkage disequilibrium using landscape and population genetics approaches. Alternative historic dispersal pathways were assessed using discriminant analysis of principle components and electrical circuit theory. KEY RESULTS: A combination of decreasing diversity, high gene flow, and landscape connectivity indicates that mountain hemlock colonization on the Kenai Peninsula is the result of long-distance dispersal. We found that contemporary climate best explained gene flow patterns and that isolation by resistance was a better model explaining genetic variation than isolation by distance. CONCLUSIONS: Our findings support the conclusion that mountain hemlock colonization is the result of several long-distance dispersal events following Pleistocene glaciation. The high dispersal capability suggests that mountain hemlock may be able to respond to future climate change and expand its range as new habitat opens along its northern distribution.
PREMISE OF THE STUDY: Untangling alternative historic dispersal pathways in long-lived tree species is critical to better understand how temperate tree species may respond to climatic change. However, disentangling these alternative pathways is often difficult. Emerging genomic technologies and landscape genetics techniques improve our ability to assess these pathways in natural systems. We address the question to what degree have microrefugial patches and long-distance dispersal been responsible for the colonization of mountain hemlock (Tsuga mertensiana) on the Alaskan Kenai Peninsula. METHODS: We used double-digest restriction-associated DNA sequencing (ddRADseq) to identify genetic variants across eight mountain hemlock sample sites on the Kenai Peninsula, Alaska. We assessed genetic diversity and linkage disequilibrium using landscape and population genetics approaches. Alternative historic dispersal pathways were assessed using discriminant analysis of principle components and electrical circuit theory. KEY RESULTS: A combination of decreasing diversity, high gene flow, and landscape connectivity indicates that mountain hemlock colonization on the Kenai Peninsula is the result of long-distance dispersal. We found that contemporary climate best explained gene flow patterns and that isolation by resistance was a better model explaining genetic variation than isolation by distance. CONCLUSIONS: Our findings support the conclusion that mountain hemlock colonization is the result of several long-distance dispersal events following Pleistocene glaciation. The high dispersal capability suggests that mountain hemlock may be able to respond to future climate change and expand its range as new habitat opens along its northern distribution.
Authors: Eugeniya I Bondar; Yuliya A Putintseva; Nataliya V Oreshkova; Konstantin V Krutovsky Journal: BMC Bioinformatics Date: 2019-02-05 Impact factor: 3.169
Authors: Haldre S Rogers; Noelle G Beckman; Florian Hartig; Jeremy S Johnson; Gesine Pufal; Katriona Shea; Damaris Zurell; James M Bullock; Robert Stephen Cantrell; Bette Loiselle; Liba Pejchar; Onja H Razafindratsima; Manette E Sandor; Eugene W Schupp; W Christopher Strickland; Jenny Zambrano Journal: AoB Plants Date: 2019-09-03 Impact factor: 3.138