Species of Diaporthe are important plant pathogens of a wide range of hosts worldwide. In the present study the species causing melanose and stem end rot diseases of Citrus spp. are revised. Three species of Diaporthe occurring on Citrus are characterised, including D. citri, D. cytosporella and D. foeniculina. Morphology and phylogenetic analyses of the complete nuclear ribosomal internal transcribed spacer regions and partial sequences of actin, beta-tubulin, calmodulin and translation elongation factor 1-alpha were used to resolve species on Citrus and related Diaporthe species. Diaporthe citri occurs on Citrus throughout the Citrus-growing regions of the world. Diaporthe cytosporella is found on Citrus in Europe and California (USA). Diaporthe foeniculina, including the synonym D. neotheicola, is recognised as a species with an extensive host range including Citrus. Diaporthe medusaea, a name widely used for D. citri, was determined to be a synonym of D. rudis, a species with a broad host range. Diaporthe citri is delimited based on molecular phylogenetic analysis with the inclusion of the conserved ex-type and additional collections from different geographic locations worldwide. D. cytosporella, D. foeniculina and D. rudis are epitypified, fully described and illustrated with a review of all synonyms based on molecular data and morphological studies. Newly designed primers are introduced to optimise the amplification and sequencing of calmodulin and actin genes in Diaporthe. A discussion is provided of the utility of genes and the need for multi-gene phylogenies when distinguishing species of Diaporthe or describing new species.

Among a French collection of 150 Diaporthe helianthi / Phomopsis helianthi Munt.-Cvet. isolates collected on sunflower since 1995, 4 were chosen for their different characteristics according to their geographic origin and the part of the infected plant where they were sampled (leaf, petiole, capitulum). Phenotypic and molecular characterisation studies were conducted on these isolates. Phenotypic studies corresponded to their linear and ponderal growths, their morphology in culture on agar medium and their aggressiveness on sunflower leaf and stem through artificial contaminations in the field. Molecular characterisation concerned on one hand the whole genome (AFLP) and on the other hand the ITS sequences. The 4 isolates present phenotypic differences in their growth in vitro, their morphology (ability to differentiate perithecia) and their aggressiveness on sunflower. Similar variability was also observed in AFLP analyses of the D./P. helianthi genome. This fungus appears to have a...

Phomopsis sp., the imperfect stage of the genus Diaporthe, is an increasingly common fungal pathogen of peach (Prunus persica). This study is the first report of the occurrence of a shoot blight and canker disease of peach in Greece caused by the fungus Diaporthe eres. The pathogen caused distinct cankers with abundant gumming on shoots of peach and nectarine trees. The rate of development of D. eres in vitro was reduced as temperatures increased from 25 to 30°C or decreased from 25 to 15°C, and was totally inhibited at 35 and 10°C. Storage at 10°C of peach fruit inoculated with D. eres controlled the development of fruit rot. Pathogenicity tests showed that 27 peach and nectarine cultivars grown in Imathia Prefecture, Greece, were equally susceptible to D. eres. The fungicides thiophanate methyl, carbendazim, tebuconazole, iprodione, and the mixture of cyprodinil:fludioxonil were evaluated against the development of D. eres and the disease symptoms. Thiophanate methyl, carbendazim,...

Blueberries (Vaccinium corymbosum) are widely cultivated worldwide and largely consumed due to their known antioxidant and medicinal properties. Although Diaporthe species have been documented in Portugal as causal agents of blueberry twig blight and dieback, there is still scarce information on the species that cause these symptoms. Moreover, Diaporthe vaccinii, recently synonymized with D. eres, has been considered a concern to blueberry production worldwide. However, the current knowledge about its impact on blueberries remains unclear. The diversity of Diaporthe species associated with diseased blueberry plants were assessed through a national survey. A multilocus sequence analysis of the rDNA internal transcribed spacer (ITS) region, the translation elongation factor 1-alpha (tef1-α), β-tubulin (tub2), calmodulin (cal) and histone 3 (his3) genes unveiled the presence of Diaporthe ambigua, D. amygdali, D. crousii, D. foeniculina, D. hybrida, D. leucospermi, D. malorum and D. rud...