Interacting elevated CO2 and tropospheric O3 predisposes aspen (Populus tremuloides Michx.) to infection by rust (Melampsora medusae f. sp. tremuloidae)
We investigated the interaction of elevated CO2 and/or (Ozone) O3 on the occurrence and severity of aspen leaf rust (Melampsora medusae Thuem. f. sp. tremuloidae) on trembling aspen (Populus tremuloides Michx.). Furthermore, we examined the role of changes in leaf surface properties induced by elevated CO2 and/or O3 in this host–pathogen interaction. Three- to five-fold increases in levels of rust infection index were found in 2 consecutive years following growing-season-long exposures with either O3 alone or CO2 + O3 depending on aspen clone. Examination of leaf surface properties (wax appearance, wax amount, wax chemical composition, leaf surface and wettability) suggested significant effects by O3 and CO2 + O3. We conclude that elevated O3 is altering aspen leaf surfaces in such a way that it is likely predisposing the plants to increased infection by aspen leaf rust.
Document Type: Research Article
Affiliations: 1: Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931 USA, 2: Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, PO Box 4000, Fredericton, NB E3B 5P7, Canada, 3: Natural Resources Canada, Canadian Forest Service-Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada, 4: Forest Research Institute, T.G. Masarykova Street 2195, 960 92 Zvolen, Slovakia, 5: Natural Resources Canada, Canadian Forest Service-Great Lakes Forestry Centre, 1219 Queen Street, PO Box 490, Sault Ste. Marie, ON P6A 5M7, Canada, 6: USDA Forest Service, North Central Research Station, Forestry Sciences Laboratory, 5985 Highway K, Rhinelander, Wisconsin 54501 USA
Publication date: 2002-04-01