• Ph.D. (Biological Sciences) 1987, University of Rhode Island
• M.A. (Biology) 1982, Rhode Island College
• B.S. (Pharmacy) 1978, University of Rhode Island

Dr. Gemma’s research focuses on arbuscular mycorrhizal (AM) fungi and their ecology and physiology. Of special concern are the early events that lead to the formation of the symbiosis between plant roots and these mutualistic fungi. A culturing system using root-organ cultures has been developed to monitor the effects of volatile root exudates on the behavior of fungal hyphae and the response of plant roots to contact by hyphae. Other research interests include the mycorrhizal relationships of ferns and fern-allies and the role of AM fungi in plant succession and restoration of disturbed habitats. Recent studies of revegetation of barren dunes at Cape Cod National Seashore and on Hawaiian beaches and young lava flows have explored the relationship between plants, fungi, and development of vegetative cover. The ability of AM fungi to enhance the drought tolerance of plants is another area of research of interest to Dr. Gemma as is the use of AM fungi in cultivating endangered plant species. Dutch elm disease and biocontrol also are of interest.

• Gemma, J.N., and R.E Koske. 1997. Arbuscular mycorrhizae in sand dune plants of the North Atlantic coast of the U.S.: Field and greenhouse studies. Journal of Environmental Management 50:251-264.


• Gemma, J.N. and R.E. Koske. 1995. Mycorrhizae in Hawaiian epiphytes. Pacific Science. 49:175-180.


• Gemma, J.N. and R.E. Koske. 1992. Are mycorrhizas present in early stages of primary succession? Pp. 183-189. In: Proceedings of Third European Symposium on Mycorrhizas: Mycorrhizas in Ecosystems. (eds. D.R. Read, D.H. Lewis, A.H. Fitter, and I.J. Alexander). CAB International.


• Gemma, J.N., R.E. Koske, and T. Flynn. 1992. Mycorrhizae in Hawaiian pteridophytes: occurrence and evolutionary significance. American Journal of Botany 79: 843-852.


• Gemma, J.N. and R.E. Koske. 1989. Field inoculation of American beachgrass, (Ammophila breviligulata) with VA mycorrhizal fungi. Journal of Environmental Management 29:173-182.


• Gemma, J.N. and R.E. Koske. 1988. Pre-infection interactions between roots and themycorrhizal fungus, Gigaspora gigantea: chemotropism of germ tubes and root growth response. Transactions of the British Mycological Society 91: 123-132.