Evidence for the role of synchronicity between host phenology and pathogen activity in the distribution of sudden oak death canker disease

Abstract

Summary• Variations in synchronicity between colonization rate by the pathogen and host phenology may account for unexplained spatial distribution of canker disease. The hypothesis that synchronous pathogenicity and host development are necessary for incidence of sudden oak death disease was tested by correlating seasonal variations in host cambial phenology and response to inoculation with Phytophthora ramorum.• Response to infection was estimated by inoculating branch cuttings from coast live oak (Quercus agrifolia) trees at nine dates through a full annual cycle in [2003][2004]. Host phenology was estimated from measurements of bud burst and cambial activity in spring 2006.• Lesions were largest in the spring soon after the cambium resumed activity. A moderate genetic component to lesion size was detected. Variation among trees in date of largest lesions correlated with variation in timing of bud burst and cambial phenology.• The data support the hypothesis that active host cambial tissue is a necessary requisite for successful infection with the pathogen that causes sudden oak death canker disease. Genetic variation in host phenology will buffer coast live oak against epidemics of this disease.

Lights, Rhythms, Infection: The Role of Light and the Circadian Clock in Determining the Outcome of Plant–Pathogen Interactions

“…Based on epidemiological studies, vaccination programs are performed on seasonal bases to reduce the incidence of human influenza and other diseases. The incidence and spatial distribution of canker disease in oak trees has been attributed to the need for synchronicity of pathogen activity and seasonal host development (Dodd et al, 2008). The peak of sporulation by Phytophtora ramorum and Fusarium circinatum, the casual agents of sudden oak death canker disease and pine pitch canker, respectively, is when the climate is cool and humid (Schweigkofler et al, 2004;Dodd et al, 2008).…”

“…The incidence and spatial distribution of canker disease in oak trees has been attributed to the need for synchronicity of pathogen activity and seasonal host development (Dodd et al, 2008). The peak of sporulation by Phytophtora ramorum and Fusarium circinatum, the casual agents of sudden oak death canker disease and pine pitch canker, respectively, is when the climate is cool and humid (Schweigkofler et al, 2004;Dodd et al, 2008). Dodd et al (2008) demonstrated that the development of sudden oak death canker disease required coincidence of pathogen sporulation and activity of the host cambial tissue, and they found a strong correlation between date of largest lesion size and timing of spring bud burst.…”

“…The peak of sporulation by Phytophtora ramorum and Fusarium circinatum, the casual agents of sudden oak death canker disease and pine pitch canker, respectively, is when the climate is cool and humid (Schweigkofler et al, 2004;Dodd et al, 2008). Dodd et al (2008) demonstrated that the development of sudden oak death canker disease required coincidence of pathogen sporulation and activity of the host cambial tissue, and they found a strong correlation between date of largest lesion size and timing of spring bud burst. This implies that not only do particular environmental conditions favor pathogen activity and infection but that there are specific times in development when the host is more susceptible to successful infection and disease development than others.…”

Impacts of climate change on plant diseases—opinions and trends

“…Climate change could make forests on the West Coast of the USA even more susceptible to this pathogen, in case of warmer temperatures during spring precipitations (Venette 2009). P. ramorum-inoculated branch cuttings of coast live oaks (Quercus agrifolia) developed larger lesions in spring, a result interpreted to suggest a role of synchronicity between host cambium activity and pathogen colonization rate (Dodd et al 2008). Such co-occurrences between host phenology and pathogen sporulation are likely to be affected by climate shifts (Donnelly et al 2011).…”

Scientific Opinion on the Pest Risk Analysis onPhytophthora ramorumprepared by the FP6 project RAPRA

“…This spike in coast live oak mortality is predicted to markedly lower its basal area in the studied forests. However other research documents a correlation between variation among trees in date of largest lesions and variation in timing of bud burst and cambial phenology (Dodd et al, 2008).…”