Studies to assess ecological
genetics and evolutionary
relationships in Artemisia tridentata
Bryce Richardson, USDA Forest Service-RMRS, Provo
Nancy Shaw, USDA Forest Service-RMRS, Boise
Joshua Udall, Department of Plant of Wildlife Sciences,
Brigham Young University
Prabin Bajgain, Department of Plant of Wildlife Sciences,
Brigham Young University
Research questions

How does quantitative traits (growth and
phenology) vary across the landscape?
◦ What climatic factors are driving adaptive
variation?
◦ Between races? Within race?

How will climate change affect big
sagebrush?
◦ Shifts in distributions? species, race,
population level?
Research questions

What are the evolutionary relationships
among and within big sagebrush races?
◦ Is wyomingensis a monophyletic lineage?
◦ Is gene flow between races common?

Does big sagebrush hybridize with other
species?
◦ What environments are conducive for
hybrids?

How does polyploidy influence adaptation
to climate?
Approach

Common garden trials
◦ Orchard, ID: wyomingensis/tridentata site
3200 ft (975 meters)
◦ Ephraim, UT: tridentata 5531 ft (1686 m)
◦ Ephraim Canyon, UT: vaseyana 6890 ft (2100
m)

Plot design
◦ 570 plants from 57 collection sites (10
replicates)
◦ Addresses: adaptive variation and potential
impacts from climate change
Approach

Bioclimatic model
◦ Collect rangewide presence
and absence data of A. tridentata
 Requires latitude, longitude and elevation data
◦ Classify presence / absence with climate data
◦ Empirically defines range map for A. tridentata
and races
◦ Comparison with racial variation defined by
adaptive traits
Approach

Bioclimatic model
Approach

Molecular genetics
◦ Marker development using next generation
sequencing (454 pyrosequencing)
◦ Transcriptome sequencing (RNA) in A. t.
tridentata and A. t. vaseyana
◦ Addresses: evolutionary relationships, intraand interspecific hybridization and population
genetics
Progress

Seed collections for common gardens
◦ ~ 70 seed sources collected
◦ Seeds from 56 sources are being sown
◦ Outplanting in April-June depending on
location
Collection sites
Progress

Molecular genetics
◦ 320,000,000 base pairs of DNA sequence has
been generated in A.t. tridentata
◦ Used in marker development
◦ A.t. vaseyana is scheduled to be sequenced
next week
Acknowledgements
Seed collections:
 BLM Districts
 Seeds of Success
 USDA Forest Service
 USDA ARS
 USDA NRCS
 Eastern Oregon Stewardship Service
Funding:
 GBNPSIP
 USDA RMRS GSD Program