Cruzan Lab - Portland State University - Biology



People in the Lab  --  Mitch Cruzan, PI 

                                                            Google Scholar Profile

Current Lab Members

Pam Thompson, Post-Doctoral Research Associate. Pam's web page.
Dispersal and gene flow under pressure from climate change in upland prairie plants.

Tina Arredondo, MS Candate. McNair Scholar
Landscape genetics in Brachypodium sylvaticum

Jaime Schwoch, MS Candate. McNair Scholar
Clonal evolution in the common monkey flower, Mimulus guttatus

Jessica Persinger, MS Candidate.

Nicolas Diaz, PhD

Cammille Mitchell, Biology Honors Candidate - Undergraduate independent research
Phenotypic selection during range expansion in Brachypodium sylvaticum

Katie Gerloff, Biology Honors Candidate
Ecological niche modelling for a widespread and endemic species of Ranunculus

Former Lab Members

Brendan Korhn, MS 2017
Phylogeography and landscape genetics of upland prairie plants on the American west coast

Monica Grasty, MS 2017
Fine-scale landscape genetics in upland prairie plants

Elizabeth Hendrickson,
Honors College - Honors Thesis 2017
Pollen-mediated gene flow in California goldfields.

Gina Marchini, PhD 2015
Mechanisms of Adaptation in the Newly Invasive Species Brachypodium sylvaticum

  • Marchini, G.L., N. Cole Sherlock. A.P. Ramakrishnan, D.M. Rosenthal, and M.B. Cruzan. Range expansion facilitates rapid purging of mutational load. Biological Invasions (in press). DOI 10.1007/s10530-015-1001-5
  • Fox SE, J Preece, JA Kimbrel, GL Marchini, A Sage, K Youens-Clark, MB Cruzan ... 2013. Sequencing and De Novo Transcriptome Assembly of Brachypodium sylvaticum (Poaceae).  Applications in Plant Sciences 1 (3)

Nena Cole Sherlock, Undergraduate independent research
Evolution during range expansion; models and numerical analyses

  • Marchini, G.L., N. Cole Sherlock. A.P. Ramakrishnan, D.M. Rosenthal, and M.B. Cruzan. Range expansion facilitates rapid purging of mutational load. Biological Invasions (in press). DOI 10.1007/s10530-015-1001-5

Elinore Webb, Undergraduate independent research
Effects of mycorrhizal associations on competitive outcomes in slender false brome.

Darla Boyle, Undergraduate independent research
Effects of invasive and native AMF communities on seedling establishment.

Jered Thompson, Undergraduate independent research
Autogamy depression in monkey flower - effects of gametophytic selection

Caitlin Lee, MS 2014
Evolution of mutualisms; mycorrhizal associations in the invasive false brome, Brachypodium sylvaticum.

Michelle Williamson, Honors Thesis 2014
Variation in functional traits across native and invasive populations of false brome.

Rachael Workman, MS 2014
Role of common mycelial networks for invasion success.

Tanya Cheeke, PhD 2013
Mycorrhizal associations in genetically modified corn.

  • Cheeke, T.E., U.M. Schütte, C.M. Hemmerich, M.B. Cruzan, T.N. Rosenstiel, and J.D. Bever.  2015. Spatial soil heterogeneity has a greater effect on symbiotic arbuscular mycorrhizal fungal communities and plant growth than genetic modification with Bacillus thuringiensis toxin genes. Molecular Ecology (in press).
  • Cheeke, T. E., H. Darby, T. N. Rosenstiel, J. Bever, and M. B. Cruzan. 2014. Effect of Bacillus thuringiensis (Bt) maize cultivation history on arbuscular mycorrhizal fungal colonization, spore abundance and diversity, and plant growth. Agriculture Ecosystems & Environment 195:29-35.
  • Cheeke T.E., MB Cruzan, TN Rosenstiel. 2013. Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize.  Applied and environmental microbiology 79 (13), 4078-4086
  • Cheeke, T.E., T.N. Rosenstiel, and M.B. Cruzan. 2012. Evidence of reduced arbuscular mycorrhizal fungal colonization in multiple lines of Bt maize. American Journal of Botany 99:700-707.
  • Cheeke, T.E., B.A. Pace, T.N. Rosenstiel, and M.B. Cruzan. 2011. The in£uence of fertilizer level and spore density on arbuscular mycorrhizal colonization of transgenic Bt 11 maize (Zea mays) in experimental microcosms. FEMS Microbiol Ecology 75:304–312.

Caitlin Maraist, Honors Thesis 2013
Functional trait plasticity in response to drought in the invasive false brome.

Erik Hasenkopf, Honors Thesis 2012
Effect of leaf litter composition and depth on the early success of the invasive grass, Brachypodium sylvaticum.

Jennifer Jones, Post-Bac research
Two hundred years of plant introductions in Portland; vegetation change under urbanization pressure.

Laura Taylor, MS 2011
Haitat invasibility by false brome.

  • Taylor, L. A. V., E. A. Hasenkopf, and M. B. Cruzan. 2015. Barriers to invasive infilling by Brachypodium sylvaticum in Pacific Northwest forests. Biological Invasions (in press).
  • Taylor, L. A. V. and M. B. Cruzan. 2015. Propagule pressure and disturbance drive the invasion of perennial false brome (Brachypodium sylvaticum). Invasive Plant Science and Management (in press).
  • Taylor, L.A.V., and M.B. Cruzan. In review. Propagule pressure and disturbance drive the spread of an invasive grass, Brachypodium sylvaticum

Alisa Ramakrishnan, PhD 2010
Evolution and spread of the newly invasive false brome, Brachypodium sylvaticum.

  • Ramakrisnnan, A.P. and M.B. Cruzan. In preparation. Founder effects and bottlenecks strongly influence colonization dynamics in a nascent invasive species.
  • Ramakrishnan, A. P., T. Musial, and M. B. Cruzan. 2010. Shifting dispersal modes at an expanding species’ range margin. Molecular Ecology 19:1134-1146.
  • Ramakrishnan, A.P.,  D.M. Rosenthal, T. Musial, and M.B. Cruzan. 2008.  Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in Oregon.  Molecular Ecology Resources 8:1297-1299.
  • Ramakrishnan, A.P. 2008.  Dispersal-Migration.  In Encyclopedia of Ecology, Elsevier.

Paul Sochacki, MS 2009
Mycorrhizal associations in Piriqueta hybrid and parental genotypes.

  • Sochacki, P., Rhode Ward, J., and M.B. Cruzan. In press. Consequences of Mycorrhizal Colonization for Piriqueta Morphotypes under Drought Stress. International Journal of Plant Sciences 174: 65-73.

Trieste Musial, MS 2009
Landscape genetics of Oregon cougars.

  • Musial, T.S., Ruedas, L.A., and M. B. Cruzan. In review. Landscape genetic analyses reveal evidence for secondary contact between discrete lindeages of Puma concolor in Oregon.
  • Ramakrishnan, A. P., T. Musial, and M. B. Cruzan. 2010. Shifting dispersal modes at an expanding species’ range margin. Molecular Ecology 19:1134-1146.
  • Ramakrishnan, A.P.,  D.M. Rosenthal, T. Musial, and M.B. Cruzan. 2008.  Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in Oregon.  Molecular Ecology Resources 8:1297-1299.

Brian Pace, Honors Thesis 2008
Effects of Nutrient Stress in Genetically Modified Bt Corn: Infectivity of Mutualistic Vesicular-Arbuscular Mycorrhizal Fungi.

  • Cheeke, T.E., B.A. Pace, T.N. Rosenstiel, and M.B. Cruzan. 2011. The in£uence of fertilizer level and spore density on arbuscular mycorrhizal colonization of transgenic Bt 11 maize (Zea mays) in experimental microcosms. FEMS Microbiol Ecology 75:304–312.

Jennifer Lawson, Honors Thesis 2008
Relative Growth Rate in the locally invasive grass Brachypodium sylvaticum.

Kristin Anton, MS 2008.  Robert Noyce Scholarship for Science Educators recipient in the PSU certification program.

  • Anton, K.A., J.M. Rhode Ward, and M.B. Cruzan. In press. Pollinator-mediated selection on floral morphology; evidence for transgressive evolution in a derived hybrid lineage. Journal of Evolutionary Biology 26: 660-673.

Heather Machado, MS 2007. Fullbright Scholar 2007 - 2008, Corrientes, Argentina.

  • Machado, H.E. and M.B. Cruzan. 2010. Intraspecific variation in gene expression under prolonged drought in Piriqueta hybrids and their parental taxa.  Plant Sciences 128:429-439.

David Rosenthal, Post Doctoral Research Associate.  Currently in a tenure-track faculty position at Ohio University, Athens, OH..

  • Rosenthal, D.M., A.P. Ramakrishnan, and M.B. Cruzan. 2008.  Evidence for multiple sources and intraspecific hybridization at early stages of the invasion of Brachypodium sylvaticum (Hudson) Beauv. in North America. Molecular Ecology 17:4657-4669.
  • Picotte, J.J., D.M. Rosenthal, J.M. Rhode, and M.B. Cruzan. 2007. Plastic responses to temporal variation in moisture availability: consequences for water use efficiency and plant performance. Oecologia 153:821-832.
  • Ramakrishnan, A.P.,  D.M. Rosenthal, T. Musial, and M.B. Cruzan. 2008.  Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in Oregon.  Molecular Ecology Resources 8:1297-1299.

Josh Picotte, MS 2006.  Currently at the USGS research facility in Wyoming.

  • Picotte, J.J., D.M. Rosenthal, J.M. Rhode, and M.B. Cruzan. 2007. Plastic responses to temporal variation in moisture availability: consequences for water use efficiency and plant performance. Oecologia 153:821-832.
  • Picotte, J.J., J.M. Rhode, and M.B. Cruzan. 2008.  Leaf morphological responses to variation in water availability for plants in the Piriqueta caroliniana complex.  Plant Ecology 200:267-275.

Bryan Benz, MS 2006.  Currently working as a Botanist for the Umpqua National Forest.

  • Benz, B.R., J.M. Rhode, and M.B. Cruzan. 2007. Aerenchyma development and elevated alcohol dehydrogenase activity as alternative responses to hypoxic soils in the Piriqueta caroliniana complex. American Journal of Botany 94: 542-550

Jennifer Rhode Ward, Post Doctoral Research Associate.  Currently tenure-track faculty at University on North Carlolina at Asheville.

  • Anton, K.A., J.M. Rhode Ward, and M.B. Cruzan. 2013. Pollinator-mediated selection on floral morphology; evidence for transgressive evolution in a derived hybrid lineage. Journal of Evolutionary Biology 26: 660-673.
  • Sochacki, P., Rhode Ward, J., and M.B. Cruzan. 2013. Consequences of Mycorrhizal Colonization for Piriqueta Morphotypes under Drought Stress. International Journal of Plant Sciences 174: 65-73.
  • Picotte, J.J., J.M. Rhode, and M.B. Cruzan. 2008.  Leaf morphological responses to variation in water availability for plants in the Piriqueta caroliniana complex.  Plant Ecology 200:267-275.
  • Benz, B. R., J. M. Rhode, and M. B. Cruzan. 2007. Root anatomical and physiological responses to flooding in the Piriqueta caroliniana complex. Am. J. Bot. 94:542-550.
  • Picotte, J.J., D.M. Rosenthal, J.M. Rhode, and M.B. Cruzan. 2007. Plastic responses to temporal variation in moisture availability: consequences for water use efficiency and plant performance. Oecologia 153:821-832.
  • Rhode, J. M., and M. B. Cruzan. 2005. Contributions of heterosis and epistasis to hybrid fitness. The American Naturalist 166:E124-E139.
  • Cruzan, M. B., and J. M. Rhode. 2004. Experimental analysis of adaptive landscape topographies. Pp. 61-69 in Q. C. B. Cronk, J. Whitton, R. H. Ree, and I. E. P. Taylor, eds. Plant Adaptation: Molecular Genetics and Ecology. National Research Council of Canada, Vancouver, B.C.

Jon Martin, Undergraduate independent research. PSU undergraduate Scholarly and Creative Activity Grant recipient (earned an MS from the Department of Biology, PSU in animal physiology).
SSR marker development and clonal population genetics in Piriqueta..

Katy McQuinn, Undergradute independent research. PSU undergraduate Scholarly and Creative Activity Grant recipient .
Morphological responses to drought and flood conditions in Piriqueta hybrid.

Allison Fortner, National Science Foundation REU student (earned an MS from the University of Oklahoma).
Fitness consequences of cyto-nuclear epistasis in a Piriqueta hybrid zone.

Sara Handy, National Science Foundation REU student (PhD from the University of Delaware.  Currently a post-doc at the University of Maryland).
Patterns of fluctuating asymmetry in Piriqueta hybrids.

  • Handy, S.M., K. McBreen, and M.B. Cruzan. 2004. Patterns of fitness and fluctuating asymmetry across a broad hybrid zone. International Journal of Plant Sciences 165: 973-981.

Chuck Price, National Science Foundation REU student (PhD from the University of Arizona; currently a post-doc at the Georgia Institue of Technology).
Patterns of concerted evolution across hybrid Piriqueta populations

Ashley Morris, MS 2000, Department of Botany (Ph.D. from the University of Florida; currently an Assistant Professor at the Middle Tennessee State University). 

  • Morris A.B., R.L. Small, and M.B. Cruzan.  2004. Variation in frequency of clonal reproduction among populations of Fagus grandifolia Ehrh. in response to disturbance. Castanea 69:38-51.
  • Morris, A.B., R. Baucom, and M.B. Cruzan. 2002. Stratified analysis of the soil seed bank in the cedar glade endemic, Astragalus bibullatus: Evidence for historical changes in genetic structure. American Journal of Botany: 89 29-36.
  • Morris A.B., R.L. Small, and M.B. Cruzan.  2003.  Investigating the relationship between Cryptococcus fagisuga and Fagus grandifolia in Great Smoky Mountains National Park.  Southeastern Naturalist 1:415-424.

Regina Baucom, Undergraduate independent research (PhD from the University of Georgia Department of Genetics; currently Assistant Professor at the University of Cincinnati).
Landscape genetics of sugar maples in response to logging history.

  • Baucom, R. S., J. C. Estill, and M. B. Cruzan. 2005. The effect of deforestation on the genetic diversity and structure in Acer saccharum (Marsh): Evidence for the loss and restructuring of genetic variation in a natural system. Conservation Genetics 6:39-50.

Jamie Estill, MS candidate, Department of Botany (Research Technician at the University of Georgia).
Phylogeography of Phacelia fimbriata and Pityopsis ruthii.

  • Estill, J. C., and M. B. Cruzan. 2001. Phytogeography of rare plant species endemic to the Southeastern United States. Castanea 66:3-23.

Stephanie Maskas, MS 2000, Department of Botany.

  • Maskas, S.D. and M.B. Cruzan. 2000. Patterns of intraspecific diversification in the Piriqueta caroliniana complex in North America and the Bahamas. Evolution 54:515-827.

Samantha Hopkins, Honors Thesis 2000.  (PhD from the University of California at Berkeley; currently an Assistant Professor at the University or Oregon).
Annual oscillations in reproductive investment in the iteroparis perennial, Scutellaria montana: A consequence of selection for large inflorescence size?

Maureen Cunningham, PhD 1999, Department of Ecology and Evolutionary Biology.
Demographic trends and host interactions of the rare hemiparasite, Aureolaria patula (Scrophulariaceae).

Lori Martin, MS 1997, Department of Botany.

  • Martin, L.J. and M.B. Cruzan. 1999. Patterns of hybridization in the Piriqueta caroliniana complex in central Florida: Evidence for an expanding hybrid zone. Evolution: 53:1037-1049.

Jiongqian (June) Wang, MS 1997, Department of Botany.

  • Wang, J. and M.B. Cruzan. 1998. Interspecific mating in the Piriqueta caroliniana (Turneraceae) complex: effects of pollen load size and composition. American Journal of Botany: 85:1172-1179.

Amy McCaskill, MS 1997, Department of Entomology and Plant Pathology.
Host race evolution in the Pyralid moth Dicymolomia jullianalis.