First report of Phyllosticta citricarpa causing citrus black spot on Citrus sinensis and C. reticulata in India.
In December 2016, citrus black spot (CBS)-like symptoms were observed on Nagpur mandarin (Citrus reticulata), 'Mosambi' sweet orange and Cutter Valencia (Citrus sinensis) in two orchards in Nagpur district, Maharashtra, India. Later symptoms were also noticed on Nagpur mandarin and Mosambi fruits in the fresh fruit market of Nagpur. Fruit symptoms included hard spot, red-brown spot, freckle spot and virulent spot. The causal pathogen was isolated and identified as Phyllosticta citricarpa (Guignardia citricarpa) based on morphological, molecular (sequence analyses of the nuclear ribosomal internal transcribed spacer region and translation elongation factor 1-alpha gene) and pathogenicity analyses. Earlier, P. citricarpa was noted on Citrus medica leaves in Chennai, India, but there was no proof of identification and characterization of the species. This is thought to be the first report of citrus black spot caused by P. citricarpa on C. reticulata and C. sinensis in India.