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J. Mark Porter
Research Scientist, Rancho Santa Ana Botanic Garden
Associate Professor of Botany, Claremont Graduate University

Phylogenetics and systematics of Polemoniaceae



Research interests:

    My research over the past several years has been divided among three principal areas: systematics of Polemoniaceae, systematics of Cactaceae (Cacteae: Echinocactinae), and floristics.  My investigations of Polemoniaceae are particularly broad, including comparative morphology, reproductive ecology and molecular phylogenetics of the family in general and tribe Loeselieae in particular.  Within the Echinocactinae, I have been examining two unrelated genera: Pediocactus Britton & Rose and Sclerocactus Britton & Rose.  These investigations involve population level study of three endangered species, molecular phylogenetic studies, taxonomic and systematics investigations of the two genera.  The floristic studies center on two regions, California and the western US (San Juan Basin or the “Four-Corners”).

    During the past four years, my research into the systematics of Polemoniaceae has resulted in a new classification for the family, in collaboration with Dr. Leigh Johnson (Brigham Young University).  Considerable molecular data has been gathered for the 110 species of tribe Loeselieae:  nuclear ribosomal ITS, granule-bound starch synthase (waxy), chalcone synthase (Chs), glyceraldehyde 3-phosphate dehydrogenase (G3pdh), Phosphoglucose isomerase (Pgi), triose phosphate isomerase (Tpi), chloroplast trnL-F and mitochondrial nadh1 intron sequences.  In addition, comparative morphological data, comparative leaf and stem histology, leaf vascular architecture, SEMs of pollen and seeds, as well as photomicrographs of trichome morphology have also been assembled.

    Studies of Cantua have included field studies in Peru, as well as cultivation of many of the species of this genus.  Leaf clearings, SEMs of pollen and seeds, SEMs of nectary glands and ovaries, data on nectar production, and corolla morphology has been acquired (see supplementary data).  In collaboration with Dr. Allan Prather, Michigan State University I am planning another trip to Peru in May-June 2002, for collections of several unnamed taxa in Cantua, funded by the National Science Foundation.  During the next two years, I anticipate further data collection, completing the acquisition already started.  I also am planning an article (in collaboration with Dylan Hannon) on the cultivation and the cultivars of Cantua.  If there is sufficient time I may also publish a taxonomic review of Cantua in Aliso.  I will be collaborating with Allan Prather on a monograph of Cantua.

    I have been involved with Cactus research since my undergraduate days.  Over the past two years I have completed several cactus-related projects, including treatments of Pediocactus and Sclerocactus for the Vascular Plants of Arizona project, and a preliminary chloroplast phylogeny of the genus Sclerocactus sensu strictu.  I have secured funding for an expanded trnL-F study of Sclerocactus (Cactus and Succulent Society) and also of Pediocactus (Bureau of Land Management).  The DNAs have been extracted from samples and DNA sequencing is scheduled for the fall (RA: Patrick Griffith).  I anticipate completion and publication of both of these projects.  In addition, a taxonomic review of Sclerocactus is being completed in collaboration with J. Travis Columbus and Kenneth D. Heil (see supplementary data).

    In the last year I have initiated a floristic project of the Whipple Mountains area, the farthest east portion of California.  Thus far I have made about 300 collections in the study area.  I anticipate making summer, fall and spring collections in future years, providing there is enough travel money to cover the field trips.  I anticipate that this study will require at least three more years.  As noted above, I am also a PI on the San Juan Basin Flora.  This project has been ongoing for several years; however, I have not dedicated much time to the project thus far.  I am planning to be more active in the coming years, as deadlines for the project will soon be approaching.  I will be collaborating on and/or initiating several papers describing new species from the study area (three new Astragalus species, a new Ipomopsis).  I will also be completing the treatment of Polemoniaceae of this region.   I have also been working on a treatment of the Polemoniaceae of Baja California and Baja California Sur.  I anticipate advancing this project over the next two years, as well (see supplementary data).  
    An additional commitment involves the Flora of North America.  I am contributing treatments for Pediocactus, Sclerocactus, Gilia, Aliciella, Dayia, Giliastrum, Microgilia, Navarretia, and Loeselia.  The treatments of Pediocactus and Sclerocactus are due in less than a year.


Degrees:

Ph. D., University of Arizona, Department of Ecology and Evolutionary Biology, 1993
B. S., Fort Lewis College, Durango, Colorado, 1987

Recent courses taught:

Quantitative Phylogenetics
Molecular Evolution
Morphometrics
Advanced Topics in Phylogenetics
Metaphysics and the Origin of Species

Recent papers:

Steinmann, V.A. and J.M. Porter.  2002.  Phylogenetic relationships in Euphorbieae (Euphorbiaceae) based on ITS and ndhF sequence data. Ann. Missouri Bot. Gard. 89: 453-490.

Porter, J. M. and L. A. Johnson.  2000.  A phylogenetic classification of Polemoniaceae.  Aliso 19: 55-91.

Porter, J. M., M. Kinney, and K. D. Heil. 2000.  Relationships between Sclerocactus and Toumeya (Cactaceae) based in chloroplast trnL-F sequences.  Haseltonia 7: 8-23.

Columbus, J.T., M.S. Kinney, M. E. Siqueros D., and J. M. Porter.  2000.  Phylogenetics of Bouteloua and relatives (Gramineae: Chloridoideae): Cladistic parsimony analyses of internal transcribed spacer (nrDNA) and trnL-F (cpDNA) sequences.  In S. W. L. Jacobs and J. Everett [eds.] Proceedings of the Second International Conference on the Comparative Biology of the Monocotyledons and the Third International Symposium on Grass Systematics and Evolution. Vol. 2 Grass systematics and evolution.  CSIRO Publ., Victoria, Australia.

Porter, J. M. and L. A. Johnson  1998.  Phylogenetic relationships of Polemoniaceae: inferences from mitochondrial nad1b intron sequences.  Aliso 17: 159–190.

Porter, J. M.  1998.  Aliciella, a recircumscribed genus of Polemoniaceae.  Aliso 17: 23–46.

Spencer, S. C. and J. M. Porter.  1997.  Evolutionary diversification and adaptation to novel environments in Navarretia (Polemoniaceae).  Systematic Botany 22: 649–668.

Porter, J. M.  1996.  Phylogeny of Polemoniaceae based on nuclear ribosomal internal transcribed spacer DNA sequences.  Aliso 15: 57–77.

Baldwin, B., C. S. Campbell, J. M. Porter, M. J. Sanderson, M. F. Wojciechowski, and M. J. Donoghue.  1995. Utility of nuclear ribosomal DNA ITS sequences in phylogenetic analyses of angiosperms.  Ann. Missouri Bot. Gard. 82: 247–277.

Present and former graduate students:

Gerard Allen (Ph. D.)
Julie Green (M.S.)
Rashmi Pant (Ph. D.)
Junzhuan Qiu (Ph. D.)
Victor Steinmann (Ph. D.)
Megan Tommerup (Ph. D.)
Michael A. Honer (M.S.)
Sarah De Groot (M.S.; Ph.D. current student)
M. Patrick Griffith (Ph.D.)
Stephen Dreher (Ph.D., current candidate)
Gary Kovnat (Ph.D., current candidate)
Robert Lauri (Ph.D. current student)

Post-graduate Scholars:

Dr. Gracielza dos Santos
Dr. Leigh A. Johnson

Link to photographs of Polemoniaceae and Cactaceae