Canadian Forest Service Publications

Interacting elevated CO2 and tropospheric O3 predisposes aspen (Populus tremuloides Michx.) to infection by rust (Melampsora medusae f. sp. tremuloidae.) 2002. Karnosky, D.F.; Percy, K.E.; Xiang, B.; Callan, B.E.; Noormets, A.; Mankovska, B.; Hopkin, A.A.; Sober, J.; Jones, W.; Dickson, R.E.; Isebrands, J.G. Global Change Biology 8: 329-338.

Year: 2002

Available from: Pacific Forestry Centre

Catalog ID: 19680

Language: English

CFS Availability: Order paper copy (free)

Abstract

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 the 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.

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