|Differential fitness in ecotypes of the pitch canker pathogen: implications for climate change and forest health.|
T. QUESADA (1), J. A. Smith (1). (1) University of Florida, Gainesville, FL, U.S.A.
Pitch canker, caused by the necrotrophic fungus <i>Fusarium circinatum,</i> is one of the major diseases in pines, affecting forests and commercial plantations worldwide. Depending on environmental factors, major outbreaks may occur or the pathogen may remain latent as an endophyte without causing symptoms. Increased global temperatures and altered precipitation regimes may favor conditions for pitch canker, but the current mitigation strategies rely mainly on breeding and selection of resistant host material, which takes many years to achieve. Preliminary data on growth at high temperatures (25, 28, and 31 °C) show significant changes between fungal isolates collected from throughout Florida, suggesting latitude-associated differential response to temperature stress. Our current knowledge on species-wide host susceptibility in clonally propagated loblolly pine creates the ideal platform to manipulate all corners of the disease triangle to assess the effects of this disease in a changing climate. Effects of temperature stress on sporulation and pathogenicity of <i>F. circinatum </i>isolates will also be addressed. Studying the effects of a changing climate on pitch canker disease would improve understanding of host-pathogen systems. This would allow the development of adequate prediction models for implementation of more efficient mitigation strategies aimed at improving forest health.