Species of Diaporthe on Camellia and Citrus in the Azores Islands

Species of Diaporthe are important plant pathogens, saprobes, and endophytes on a wide range of plant hosts. Species such as D. citri are well-known on Citrus, as agents of pre- or post-harvest infections, causing dieback, melanose and stem-end rot on fruit. In this study we explored the occurrence and diversity of Diaporthe associated with tropical and sub-tropical plants. In particular, species of Camellia and Citrus were sampled. Surveys were carried out during 2017 in the Azores Islands, Portugal. Ten Diaporthe strains were isolated from symptomatic twigs and leaves. Five representative isolates were subjected to morphological characterization and multi-locus phylogeny based on five genomic loci (ITS, tef1, cal, his3 and tub2). Diaporthe citri was found associated with shoot blight on Citrus reticulata, which represents a new record for Europe. A new species, Diaporthe portugallica sp. nov. was isolated and described from leaf spots on Camellia sinensis.