Fig. 1.

External and internal symptoms associated with trunk diseases of Pterocarya fraxinifolia in Asalem and Talesh (Guilan province, Northern Iran), from which Juglanconis pterocaryae was isolated. a Healthy tree. b Trees showing severe decline symptoms. c Tree showing canker and branch dieback covered by acervuli of J. pterocaryae (arrows). d Cross section of a branch showing wedge-shaped necrosis, arrows showing acervuli of J. pterocaryae. e, f Dead branches with J. pterocaryae acervuli, some with conidial cirrhi (spore tendrils). g Co-occurrence of arch-shaped necrosis (a) and young wedge-shaped necrosis (b). h Extensive central necrosis. i Co-occurrence of watery necrosis (a), irregular necrosis (b) and black wood streaking (c). j Co-occurrence of wedge-shaped necrosis (a), black spots (b) and arch-shaped necrosis (c). k Irregular wood necrosis