Gnomoniopsis smithogilvyi, a canker causing pathogen on Castanea sativa: First report

In India, sweet Chestnut (Castanea sativa Mill.) is cultivated in temperate parts of Northern India. During 2009-2013, a regular survey of cankers of chestnut was made for presence of Cryphonectria and related genera. Almost 80% of orchards were infected by fungal pathogens causing cankers. The cankers formed long regular cracks in the bark which sometimes extends to xylem tissue. In the current study, Gnomoniopsis smithogilvyi was identified using morphological and phylogenetic analysis of the ITS region of ribosomal DNA. The canker formation was clearly observed on the young sprouts, stems and branches. Here, we report Gnomoniopsis smithogilvyi as canker associated fungus on chestnut trees in India. It appears that either geographic isolation or the unique growing conditions in India may have provided an effective barrier to the achievement or establishment of pathogenesis in G. smithogilvyi. Wounds caused by mechanical injuries or pruning possibly are providing routes for infection.