Contact Information

To view a summary of current research projects in the Merkle Lab click here

Education

B.S. in Biology - College of William and Mary

M.S. in Forestry - Virginia Polytechnic Institute and State University

Ph.D. in Forestry - Virginia Polytechnic Institute and State University

Area of Specialization

• Cell and tissue culture of forest trees
• Genetic transformation of forest trees

Prior Positions

• Postdoctoral Associate - Oregon State University

Courses Taught

• FORS 3010 Dendrology
• FORS 8040 Current Topics in Forest Biotechnology

Publications (selected)

Lyyra, S., R.B. Meagher, T. Kim, A. Heaton, P. Montello, R.S. Balish, and S.A. Merkle. 2007. Coupling two mercury resistance genes in eastern cottonwood enhances processing of organomercury. Plant Biotechnology Journal 5:254-262.

Merkle, S.A., G.M. Andrade, C.J. Nairn, W.A. Powell and C.A. Maynard. 2007. Restoration of threatened species: a noble cause for transgenic trees. Tree Genetics and Gemomes 3:111-118.

Merkle, S.A., P.M. Montello, X.Xia, B.L. Upchurch and D.L. Smith. 2006. Light quality treatments enhance somatic seedling production in three southern pine species. Tree Physiol. 26:187-194.

Lyyra, S., A. Lima and S.A. Merkle. 2006. In vitro regeneration of Salix nigra via adventitious shoots. Tree Physiol. 26:969-975.

Che, D.S., R.B. Meagher, C.L. Rugh, T.R. Kim, A.C.P. Heaton and S.A. Merkle. 2006. Expression of organomerucry lyase in eastern cottonwood enhances organomercury resistance. In Vitro Cell. Dev. Biol. - Plant 42:228-234.

Merkle, S.A. 2006. Engineering forest trees with heavy metal resistance genes. Silvae Genet. 55:263-268.

Merkle, S.A., P.M. Montello, X. Xia, B.L. Upchurch and D.R. Smith. 2005. Light quality treatments enhance somatic seedling production in three southern pine species.  Tree Physiol. 26:187-194.

Merkle, S.A., and C.J. Nairn. 2005. Hardwood tree biotechnology. In Vitro Cell. Dev. Biol.- Plant 41:602-619.

Andrade, G.M., and S.A. Merkle. 2005. Enhancement of American chestnut somatic seedling production. Plant Cell Reports 24:326-334.

Dai, J., W. Vendrame and S.A. Merkle. 2004. Enhancing the productivity of hybrid yellow-poplar and hybrid sweetgum embryogenic cultures. In Vitro Cell. Dev. Biol.- Plant 40:376-383.

Robichaud, R.L., V.C. Lessard and S.A. Merkle. 2004. Treatments affecting maturation and germination of American chestnut somatic embryos. J. Plant Physiol. 161:957-969.

Che, D., R.B. Meagher, A.C.P. Heaton, A. Lima, C.L. Rugh and S.A. Merkle. 2003. Expression of mercuric ion reductase in eastern cottonwood confers mercuric ion reduction and resistance.  Plant Biotechnology Journal 1:311-319.

Merkle, S.A., P.J. Battle and G.O. Ware. 2003. Factors influencing production of inflorescence-derived somatic seedlings of sweetgum. Plant Cell, Tissue and Organ Culture 73:95-99.

Vendrame, W.A., C.P. Holliday, P.M. Montello, D.R. Smith and S.A. Merkle. 2001. Cryopreservation of yellow-poplar (Liriodendron tulipifera) and sweetgum (Liquidambar spp.) embryogenic cultures. New Forests 21:283-292.

Vendrame, W.A., C.P. Holliday and S.A. Merkle. 2001. Clonal propagation of hybrid sweetgum (L. styraciflua X L. formosana) via somatic embryogenesis. Plant Cell Reports 20:691-695.

Holliday, C.P., and S.A. Merkle. 2000. Preservation of American chestnut germplasm by cryostorage of embryogenic cultures. Journal of the American Chestnut Foundation 14(1):46-52.

Merkle, S.A., and J.F.D. Dean. 2000. Forest tree biotechnology. Current Opinion in Biotechnology 11:298-302.

Merkle, S.A., and P.J. Battle. 2000. Enhancement of embryogenic culture initiation from tissues of mature sweetgum trees. Plant Cell Reports 19:268-273.

Kim, M.K., H.E. Sommer, J.F.D. Dean and S.A. Merkle.  1999. Transformation of sweetgum via microprojectile bombardment of nodule cultures. In Vitro Cell. Dev. Biol. 35:37-42.

Merkle, S.A., K.A. Neu, P.J. Battle, and R.L. Bailey. 1998. Somatic embryogenesis and plantlet regeneration from immature and mature tissues of sweetgum (Liquidambar styraciflua) Plant Science 132: 169-178.

Rugh, C.L., G.M. Gragson, S.A. Merkle, and R.B. Meagher. 1998. Toxic mercury reduction and remediation using transgenic plants with a modified bacterial gene. HortScience 33:618-621.

Rugh, C.L., J.F. Senecoff, R.B. Meagher, and S.A. Merkle. 1998. Development of transgenic yellow poplar for mercury phytoremediation. Nature Biotechnology 16:925-928.

Kim, M.K., H.E. Sommer, B.C. Bongarten, and S.A. Merkle. 1997. High-frequency induction of adventitious shoots from hypocotyl segments of Liquidambar styraciflua L. by thidiazuron. Plant Cell Reports 16:536-540.

Merkle, S.A., R.L. Bailey, B.A. Pauley, , K.A. Neu, M.K. Kim, C.L. Rugh, and P.M. Montello. 1997. Somatic embryogenesis from tissues of mature sweetgum trees. Canadian Journal of Forest Research 27:959-964.

Carraway, D.T., and S.A. Merkle. 1997. Plantlet regeneration from somatic embryos of American chestnut. Canadian Journal of Forest Research 27:1805-1812.

Merkle, S.A., W.A. Parrott, and B.S. Flinn. 1995. Morphogenic aspects of somatic embryogenesis. In In Vitro Embryogenesis in Plants (T.A. Thorpe, ed.). Kluwer Academic Publishers, Dordrecht.  pp. 155-203.

Merkle, S.A. 1995. Strategies for dealing with limitations of somatic embryogenesis in hardwood trees. Plant Tissue Culture and Biotechnology 1:112-121.

Arrillaga, I., J.J. Tobolski, and S.A. Merkle. 1994. Advances in somatic embryogenesis and plant production in black locust (Robinia pseudoacacia L.) Plant Cell Reports 13:171-175.

Carraway, D.T., H.D. Wilde, and S.A. Merkle. 1994. Somatic embryogenesis and gene transfer in American chestnut. Journal of the American Chestnut Foundation 8(1):29-33.

Merkle, S.A., and B.A.Watson-Pauley. 1994. Ex vitro conversion of pyramid magnolia somatic embryos. HortScience 29:1186-1188.

Merkle, S.A., and B.A. Watson-Pauley. 1993. Regeneration of bigleaf magnolia by somatic embryogenesis. HortScience 28:672-673.

Merkle, S.A., M.T. Hoey, B.A. Watson-Pauley, and S.E. Schlarbaum. 1993. Propagation of Liriodendron hybrids via somatic embryogenesis. Plant Cell, Tissue and Organ Culture 34:191-198.

Arrillaga, I., and S.A. Merkle. 1993. Plant regeneration from in vitro culture of cotyledon and leaf explants of black locust. HortScience 28:942-945.

Wilde, H.D., R.B. Meagher, and S.A. Merkle. 1992. Expression of foreign genes in transgenic yellow-poplar plants. Plant Physiol. 98:114-120.

Merkle, S.A. 1992. Propagation of Liriodendron and Magnolia via somatic embryogenesis. Magnolia 27(2):1-8.

Mathews, H., R.E. Litz, H.D. Wilde, S.A. Merkle, and H.Y. Wetzstein. 1992. Stable integration and expression of ß-glucuronidase and NPT II genes in mango somatic embryos. In Vitro Cell. Dev. Biol. 28P:172-178.

Sotak, R.J., H.E. Sommer, and S.A. Merkle. 1991. Relation of the developmental stage of zygotic embryos of yellow-poplar to their somatic embryogenic potential. Plant Cell Rep. 10:175-178.

Merkle, S.A., and C.L. Brown. 1991. The American chestnut: its past, present and future in Georgia. Tipularia 5:2-13.   

Parrott, W.A., S.A. Merkle, and E.G. Williams. 1991. Somatic embryogenesis: potential for use in propagation and gene transfer systems. In Advanced Methods in Plant Breeding and Biotechnology (D.R. Murray, ed.). CAB International, Wallingford, Oxon (U.K.). pp. 158-200.

Merkle, S.A., A.T. Wiecko, and B.A. Watson-Pauley. 1991. Somatic embryogenesis in American chestnut. Can. J. For. Res. 21:1698-1701.

Merkle, S.A., and A.T. Wiecko. 1990. Somatic embryogenesis in three magnolia species. J. Am. Soc. Hort. Sci. 115:858-860.

Merkle, S.A., R.J. Sotak, A.T. Wiecko and H.E. Sommer. 1990. Maturation and conversion of Liriodendron tulipifera somatic embryos. In Vitro Cell. Dev. Biol. 26:1086-1093.

Merkle, S.A., W.A. Parrott, and E.G. Williams. 1990. Applications of somatic embryogenesis and embryo cloning. In Plant Tissue Culture: Applications and Limitations (S.S. Bhojwani, ed.). Elsevier, Amsterdam. pp. 67-101.

Wetzstein, H.Y., J.R. Ault and S.A. Merkle. 1990. Factors influencing somatic embryogenesis and plantlet regeneration in pecan, Carya illinoensis. Acta Horticulturae 280:69-71.

Merkle, S.A. and A.T. Wiecko. 1989. Regeneration of Robinia pseudoacacia via somatic embryogenesis. Can. J. For. Res. 19:285-288.

Wetzstein, H.Y., J.R. Ault and S.A. Merkle. 1989. Further characterization of somatic embryogenesis and plantlet regeneration in pecan (Carya illinoensis). Plant Sci. 64:193-201.

Merkle, S.A., W.T. Adams, and R.K. Campbell. 1988. Multivariate analysis of allozyme variation patterns in coastal Douglas-fir from southwest Oregon. Can. J. For. Res. 18:181-187.

Merkle, S.A., H.Y. Wetzstein and H.E. Sommer. 1987. Somatic embryogenesis in tissue cultures of pecan. HortScience 22:128-130.

Merkle, S.A. and W.T. Adams. 1987. Patterns of allozyme variation within and among Douglas-fir breeding zones in southwest Oregon. Can. J. For. Res. 17:402-407.

Merkle, S.A. and H.E. Sommer. 1987. Regeneration of Liriodendron tulipifera (family Magnoliaceae) from protoplast culture. Am. J. Bot. 74:1317-1321.

Merkle, S.A. and H.E. Sommer. 1986. Somatic embryogenesis in tissue cultures of Liriodendron tulipifera L. Can. J. For. Res.  16:420-422.