%0 Journal Article %J Boletiacuten de la Sociedad Argentina de Botaacutenica %D 1996 %T Hongos Aphyllophorales (Basidiomycetes) que causan pudriciones en Austrocedrus chilensis %A Barroetaveña, C. %A Rajchenberg, M. %B Boletiacuten de la Sociedad Argentina de Botaacutenica %V 31 %P 201-216 %G eng %0 Journal Article %J Forest Pathology %D 2014 %T Host removal as a potential control method for Phytophthora cinnamomi on severely impacted black gravel sites in the jarrah forest %A Crone, M. %A McComb, J. A. %A O'Brien, P. A. %A Hardy, G. E. St J. %E Andrea, V. %X

Removal of living plants from an area of Eucalyptus marginata (jarrah) forest on black gravel sites infested with Phytophthora cinnamomi significantly reduced subsequent pathogen recovery. Vegetation, including trees and annual and herbaceous perennial plants, was killed on the sites by herbicide application. To determine whether this treatment efficiently eliminated P. cinnamomi, soil samples were seasonally collected and baited to test for the presence of the pathogen. There were no recoveries on treated sites in autumn, 28 months after removal of all vegetation by herbicide application. To test whether this was the result of the complete elimination of the pathogen or whether inoculum remained, regrowth on sites was not controlled after this period leading to the re-establishment of annual and herbaceous perennial species, some of which are hosts of P. cinnamomi. Recovery of P. cinnamomi after plant regrowth on the formerly treated sites indicated that for complete pathogen removal, sites need to remain free of vegetation for longer than 28 months. Overall, however, this study confirms that the pathogen is a weak saprophyte, and withdrawal of host material for a period of time may make eventual rehabilitation of these sites possible.

%B Forest Pathology %V 44 %P 154 - 159 %8 Jan-04-2014 %G eng %U http://doi.wiley.com/10.1111/efp.2014.44.issue-2http://doi.wiley.com/10.1111/efp.12080 %N 2 %! For. Path. %R 10.1111/efp.2014.44.issue-210.1111/efp.12080 %0 Journal Article %J Plant Pathology %D 2014 %T Histopathology of infection and colonization of Quercus ilex fine roots by Phytophthora cinnamomi %A Gómez, F. J. %A Navarro-Cerrillo, R. M. %A Sánchez-Cuesta, R. %A Pérez-de-Luque, A. %X

Quercus ilex is one of the European forest species most susceptible to root rot caused by the oomycete Phytophthora cinnamomi. This disease contributes to holm oak decline, a particularly serious problem in the ‘dehesas’ ecosystem of the southwestern Iberian Peninsula. This work describes the host–pathogen interaction of Q. ilex and P. cinnamomi, using new infection indices at the tissue level. Fine roots of 6-month-old saplings inoculated with P. cinnamomi were examined by light microscopy and a random pool of images was analysed in order to calculate different indices based on the measured area of pathogen structures. In the early stages of invasion, P. cinnamomi colonizes the apoplast and penetrates cortical cells with somatic structures. On reaching the parenchymatous tissues of the central cylinder, the pathogen develops different reproductive and survival structures inside the cells and then expands through the vascular system of the root. Some host responses were identified, such as cell wall thickening, accumulation of phenolic compounds in the middle lamella of sclerenchyma tissues, and mucilage secretion blocking vascular cells. New insights into the behaviour of P. cinnamomi inside fine roots are described. Host responses fail due to rapid expansion of the pathogen and a change in its behaviour from biotrophic to necrotrophic.

%B Plant Pathology %P 605–616 %8 11/2014 %G eng %U http://doi.wiley.com/10.1111/ppa.12310 %! Plant Pathol %R 10.1111/ppa.12310 %0 Journal Article %J Phytopathology %D 2016 %T Host Phenology and Leaf Effects on Susceptibility of California Bay Laurel to Phytophthora ramorum %A Johnston, Steven F. %A Cohen, Michael F. %A Torok, Tamas %A Meentemeyer, Ross K. %A Rank, Nathan E. %X

Spread of the plant pathogen Phytophthora ramorum, causal agent of the forest disease sudden oak death, is driven by a few competent hosts that support spore production from foliar lesions. The relationship between traits of a principal foliar host, California bay laurel (Umbellularia californica), and susceptibility to P. ramorum infection were investigated with multiple P. ramorum isolates and leaves collected from multiple trees in leaf-droplet assays. We examined whether susceptibility varies with season, leaf age, or inoculum position. Bay laurel susceptibility was highest during spring and summer and lowest in winter. Older leaves (>1 year) were more susceptible than younger ones (8 to 11 months). Susceptibility was greater at leaf tips and edges than the middle of the leaf. Leaf surfaces wiped with 70% ethanol were more susceptible to P. ramorum infection than untreated leaf surfaces. Our results indicate that seasonal changes in susceptibility of U. californica significantly influence P. ramorum infection levels. Thus, in addition to environmental variables such as temperature and moisture, variability in host plant susceptibility contributes to disease establishment of P. ramorum.

%B Phytopathology %V 106 %P 47 - 55 %8 Jan-01-2016 %G eng %U http://apsjournals.apsnet.org/doi/10.1094/PHYTO-01-15-0016-R %N 1 %! Phytopathology %R 10.1094/PHYTO-01-15-0016-R %0 Journal Article %J Ecological Applications %D 2006 %T Heterogeneity shapes invasion: host size and environment influence susceptibility to a nonnative pathogen %A Kauffman, Matthew J. %A Jules, Erik S. %B Ecological Applications %V 16 %P 166-175 %G eng %U http://www.esajournals.org/doi/abs/10.1890/05-0211 %R 10.1890/05-0211 %0 Journal Article %J Phytopathology %D 2007 %T Histopathology of infection and colonization of susceptible and resistant Port-Orford-cedar by Phytophthora lateralis. %A E. Oh %A Hansen, E.M. %K Chamaecyparis lawsoniana %K developmental stages %K forest trees %K fungal anatomy %K fungal diseases of plants %K histopathology %K infection %K North America %K ornamental plants %K pathogenicity %K Phytophthora lateralis %K plant morphology %K plant pathogenic fungi %K roots %K signs and symptoms (plants) %K stems %B Phytopathology %V 97 %P 684–693 %G eng %U http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-97-6-0684 %R http://dx.doi.org/10.1094/PHYTO-97-6-0684