John J. Skvarla

My research interests are with all aspects of living and fossil pollen grain walls, the covering of the male gametophytes of seed plants. This includes ontogeny, morphology/taxonomy, comparative studies of living and fossil counterparts, pollen wall degradation by physical and biological factors, and the development and refinement of techniques to study pollen with the scanning and transmission electron microscopes. Research is conducted using traditional light, scanning and transmission electron microscopy, and the more contemporary methods of freeze-fracturing, cytochemical electron microscopy, and computerized image analysis.

Living taxa of primary interest are the angiosperm monocot families Cannaceae, Strelitziaceae and Poaceae, and the dicot families Leguminosae, Onagraceae and Asteraceae. Fossil pollen groups of interest are: Triprojecticites, a fossil assemblage without modern counterparts and which is helpful in defining the Cretaceous-Tertiary boundary; Pandaniidites, with counterparts in the living screw-pine pine family (Pandanaceae); and a group containing diverse forms like Corsinipollenites and Diporites, with relationships to the living evening-primrose (Onagraceae).

Selected Publications

• "A numerical approach to pollen sculpture terminology," E. L. Vezey, V. P. Shah and J. J. Skvarla, Plant Systematics and Evolution 181: 245-254 (1992).
• "Exine receptors," J. R. Rowley and J. J. Skvarla, Grana 2 (Suppl.): 21-25 (1993).
• "Statistical analysis of computer-generated measurements from manually outlined pollen perforations," E. L. Vezey, H. S. Yu and J. J. Skvarla, Grana 32: 250-254 (1993).
• "Mounting pollen on a thermoplastic adhesive for scanning electron microscopy," W. F. Chissoe, E. L. Vezey and J. J. Skvarla, Journal American Microscopical Society 113: 72-79 (1994).
• "Pollen morphology of Anthemideae (Compositae) and systematic implications," E. L. Vezey, L. E. Watson, J. R. Estes and J. J. Skvarla, American Journal of Botany 81: 648-657 (1994).
• "Pollen ultrastructure of Pandanaceae and the fossil genus Pandaniidites," C. L. Hotton, H. A. Leffingwell and J. J. Skvarla, Ultrastructure of Fossil Spores and Pollen (M. H. Kurmann and J. A. Doyle, eds.), The Royal Botanic Gardens, Kew (1994).
• "Hexamethyldisilazane as a drying agent for pollen scanning electron microscopy," W. F. Chissoe, E. L. Vezey and J. J. Skvarla, Biotechnic & Histochemistry 69: 192-198 (1994).
• "Corroded exines from Havinga's leaf mold experiment - structure of Fagus and Quercus exines," J. R. Rowley and J. J. Skvarla, Review of Paleobotany and Palynology 83: 65-72 (1994).
• "Searching for a foveolate exine," E. L. Vezey and J. J. Skvarla, Review of Paleobotany and Palynology 83: 73-81 (1994).
• "Onagraceae Juss. Circaeeae DC., Hauyeae Raimann, Epilobieae Spach.," J. R. Praglowski, J. N. Nowicke, J. J. Skvarla, P. C. Hoch, P. H. Raven and M. Takahashi, World Pollen and Spore Flora 19: 1-38 (1995).
• "The use of osmium-thiocarbohydrazide for structural stabilization and enhancement of secondary electron images in scanning electron microscopy," W. F. Chissoe, E. L. Vezey and J. J. Skvarla, Grana 34: 1-8 (1995).
• "Metallic conical wells for containing and transferring pollen for scanning electron microscopy," W. F. Chissoe and J. J. Skvarla, Oklahoma Academy of Science 76: 51-52. (1996).
• "Corroded exines from Havinga's leaf mold experiment. SEM," J. J. Skvarla, J. R. Rowley and W. F. Chissoe, Palynology 20: 45-57 (1996).

For more information about this program, email the Department or Dr. John Skvarla.

Other related web pages:

• Department of Botany & Microbiology
  
• Samuel Roberts Noble Electron Microscopy Lab