Host and abiotic constraints on the distribution of the pine fungal pathogen Sphaeropsis sapinea (= Diplodia sapinea)

Plant fungal pathogens are an increasing emerging threat as climate change progresses. Sphaeropsis sapinea (syn. Diplodia ), the causal agent of tip blight, is a major pathogen pines forestry and ornamental relevance in Europe worldwide. Here, we combined molecular-based field surveys common-garden setting across elevation gradient with historical records, cultivation-based growth experiments microscopy to report on host abiotic constraints distribution S. . Using arboretum at Botanical Garden Berlin, Germany, control for environmental variability, was detected all seven Pinus species studied. However, P. sylvestris only which fungus symptomless needles arboretum, most frequently recorded over century, suggesting that it main, perhaps, potential original host. In addition, sampling symptomatic four out same from 200 2,100 m French Alps, not higher than 800 m. Abiotic were also supported by reduced isolates low temperature under controlled conditions, but 35°C prior stress exposure increased subsequent within its optimal range (20-30°C). Altogether, our study thus suggests more likely cause blight compared other studied, current context global predicted increases, could infect wider pine hosts locations