John F. Gaskin

PMRU Research Leader and Botanist

Phone: 406.433.9444

Fax: 406.433.5038

• Education • Current Research • Research Experience • Related Web Pages • Publications •

Additional Pages: Research Projects,* Publications*

*Taken from the Agricultural Research Information System (ARIS) database.

EDUCATION

 

B.S. Biology	1996	University of California, Santa Cruz, CA
Ph. D. Evolutionary & Population Biology	2002	Washington University in St. Louis & Missouri Botanical Garden, MO

CURRENT RESEARCH

The focus of my research is the systematics and population structure of invasive plants, particularly whitetop or hoarycress (Lepidium draba, formerly Cardaria draba) and saltcedar (Tamarix spp.) Both of these invasives are present in Montana and throughout the western U.S. Saltcedar typically dominates riparian areas and whitetop is considered a pest plant in fields, rangelands and natural areas. The specific goals of this research are to find out which genotypes of these exotic plants are invading, where the genotypes originated from in Eurasia, which native and exotic species they are most closely related to, and where the invasive genotypes are distributed in the U.S. This information will be used to insure that all of the genetic diversity of these invasions will be present in tests of current and proposed biological control agents, and that all native plants closely related to the invasion will be included in host-specificity tests.

RESEARCH EXPERIENCE

Prior to joining the USDA-Agricultural Research Service in 2002, my dissertation at Washington University in St. Louis focused on the phylogeography of invasive Tamarix. I have done revision work on South American Smilax, and molecular systematic work in the families Campanulaceae and Tamaricaceae.

RELATED WEB PAGES

MBG: Missouri Exotic Pest Plants

• Gaskin, J.F., Wilson, L.M. 2007. Phylogenetic relationships among native and naturalized hieracium (asteraceae) in Canada and the United States based on plastid DNA sequences. Systematic Botany. 32(2):478-485.
• Whitcraft, C.R., Talley, D.M., Crooks, J.A., Boland, J., Gaskin, J.F. 2007. Invasion of tamarisk (Tamarix spp.) in a southern California salt marsh. Biological Invasions. Available: http://www.springerlink.com/content/b5557423270ug210/fulltext.pdf.
• Zhang, D., Zhang, Y., Gaskin, J.F., Chen, Z. 2006. Systematics position of Myrtama Ovcz. and Kinz. based on mophological and nr DNA ITS sequence evidence. Chinese Science Bulletin. 51:117-123.
• Sword, G.A., Senior, L., Gaskin, J.F., Joern, A. 2007. Double trouble for grasshopper molecular systematics: intra-individual heterogeneity of both mitochondrial 12S-valine-16S and nuclear internal transcribed spacer ribosomal DNA sequences in Hesperotettix viridis (Orthoptera: Acrididae). Systematic Entomology. 32(3):420-428.
• Caesar, T., Caesar, A.J., Gaskin, J.F., Sainju, U.M., Busscher, W.J. 2007. Taxonomic diversity of predominant culturable bacteria associated with microaggregates from two different agroecosystems and their ability to aggregate soil in vitro. Applied Soil Ecology. 36(1):10-21.
• Gaskin, J.F., A.E. Pepper, and J.M. Manhart. 2006. Isolation and characterization of ten polymorphic microsatellites in saltcedars (Tamarix chinensis and T. ramosissima). Molecular Ecology Notes 6:1146-1149.
• Gaskin, J.F. and D.J. Kazmer. 2006. Comparison of ornamental and invasive saltcedar in the USA northern Great Plains using chloroplast and nuclear DNA sequence markers. Wetlands 26: 939-950.
• Gaskin, J.F., Ryan, F.J., Hrusa, G.F. and Londo, J.P. 2006. Genotype diversity of Salsola tragus and potential origins of a previously unidentified invasive Salsola from California and Arizona. Madroño 53:246-253.
• Gaskin, J.F. 2006. Clonal structure of invasive hoary cress (Lepidium draba) infestations. Weed Science 54:428-434
• Gaskin, J.F. and P.E. Berry. 2005. Smilacaceae in Flora of the Venezuelan Guayana, J.A.Steyermark, P.E. Berry, K. Yatskievych and B.K. Holst (eds.). Missouri Botanical Garden Press, St. Louis, USA. Pp. 184-193.
• Gaskin, J.F., D-Y. Zhang, and M-C. Bon. 2005. Invasion of Lepidium draba (Brassicaceae) in the western United States: distributions and origins of chloroplast DNA haplotypes. Molecular Ecology 14:2331-2341.
• Gaskin, J.F. and P.B. Shafroth. 2005. Hybridization of Tamarix ramosissima and T. chinensis (saltcedars) with T. aphylla (athel) (family Tamaricaceae) in the southwestern USA determined from DNA sequence data. Madroño 52:1-10.
• Bon, M-C, C. Hurard, J. Gaskin, and A-M Risterucci. 2005. Polymorphic microsatellite markers in polyploid Lepidium draba L. subsp. draba (Brassicaceae) and cross-species amplification in closely related taxa. Molecular Ecology Primer Notes 5:68-70.
• Shulkina, T., J. Gaskin, and W. Eddie. 2003. Morphological studies toward an improved classification of Campanulaceae s. str. Ann. Missouri Bot. Gard. 90: 576-591.
• Eddie, W.M.M.,T. Shulkina, J. Gaskin, R.C. Haberle, and R.K. Jansen. 2003. Phylogeny of Campanulaceae s. str. inferred from ITS sequences of nuclear ribosomal DNA. Ann. Missouri Bot. Gard. 90: 554-575.
• Schaal, B.A., J.F. Gaskin, and A.L. Caicedo. 2003. Phylogeography, haplotype trees, and invasive plant species. J. Heredity 94 (3): 197-204.
• Gaskin, J.F. 2003. Molecular systematics and the control of invasive plants: a case study of Tamarix (Tamaricaceae). Ann. Missouri Bot. Gard. 90: 109-118.
• Gaskin, J.F. and B.A. Schaal. 2003. Molecular phylogenetic investigation of invasive Tamarix in the U.S.A. Syst. Bot. 28(1): 86-95.
• Gaskin, J.F. and B.A. Schaal. 2002. Hybrid Tamarix widespread in U.S. invasion and undetected in native Asian range. Proc. Natl. Acad. Sci. USA 99: 11256–11259.
• Gaskin, J.F. 2002. Tamaricaceae in The Families and Genera of Vascular Plants V. K. Kubitzki and C. Bayer (eds). Springer-Verlag, Berlin. Pp. 363-368.
• Berry, P.E. and J.F. Gaskin. 1998. A new Croton (Euphorbiaceae) from the western Guayana Shield and its anomalous sectional placement. Systematic Botany 23(2): 171-175.
• Gaskin, J.F. and P.E. Berry. 1998. New synonymy and useful taxonomic characters in Smilax (Smilacaceae) from the Venezuelan Guayana. Novon, 8(4):364-370.
• Gaskin, J.F. and P.E. Elvander. 1997. A new chromosome number for Saxifraga californica (Saxifragaceae) with implications for its relationships. Madroño 44(1):111-112.
• Wood, S.E., J.F. Gaskin, and J.H. Langenheim. 1995. Loss of monoterpenes from Umbellularia californica leaf litter. Biochem. Syst. and Ecol. 23 (6):581-591.

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