Lela Stanley
Host-Specific Genetic Differentiation in Eastern Dwarf Mistletoe Parasitizing Coastal Red and White Spruce
Advisor: Barry Logan
The eastern dwarf mistletoe is an aerial parasitic plant that infests red, white, and black spruce in Maine, relying on these hosts for the bulk of the water and nutrients they need. Mistletoe infection compromises the health of the host tree and is thought to lead to secondary infection by other organisms and occasionally death (Hawksworth and Weins, 1996) Coastal white spruce is especially susceptible to eastern dwarf mistletoe infection, with correspondingly higher rates or injury (Jaret Reblin and Barry Logan, pers. comm.). Recently, dwarf mistletoe species from the western United States were reported to exibit genetic differentiation that was host-specific (Linhart et al., 2003). Genetic differentiation of this sort may arise because host tree species differ greatly in internal biochemistry and therefore lead to differential adaptations via natural selection. Ms. Stanley will collect mistletoe samples from mixed stands of red and white spruce and use several molecular techniques to determine if the mistletoe samples exhibit host-specific genetic differentiation.
Sources
Hawksworth, F.G. and D. Weins (eds.) (1996) Dwarf mistletoe: biology, pathway, and systematics. Agricultural handbook 709. United States Department of Agriculture, Forest Service, Washington D.C.
Linhart, Y.B., L.M. Ellwood, J.D. Karron, and J.L. Gehring (2003) Genetic differentiation in the Dwarf Mistletoes Arceuthobium veginatum and Arceuthobium americanum on their principal and secondary hosts. Int. J. Plant Sci. 164(1):61-69.