First report of the fungus Diaporthe phaseolorum on sunflower in Russia

Abstract

Fungi of the ascomycete genus Diaporthe have been identified worldwide. Typically, Diaporthe species are saprobes, endophytes, or plant pathogens. The distinction between the species of this genus has historically been based on the combination of the morphological information, cultural characteristics, and host affiliation. The correct identification of the Diaporthe species should be carried out based on a combination of molecular genetic traits. A comprehensive analysis of Diaporthe species in the Russian Federation using molecular phylogeny methods has never been accomplished. The goal of this study was the identification of the isolate Diaporthe sp. MF 16-010, extracted from stems of Helianthus annuus L. that was collected in the Krasnodar region of the Russian Federation. According to the morphology data and DNA sequence analyses of the nuclear ribosomal internal transcribed spacer (ITS) region as well as of the translation elongation factor-1α (EF-1α) and ß-tubulin genes, the isolate MF 16-010 was identified as Diaporthe phaseolorum (Cooke & Ellis) Sacc. To the best of our knowledge, this isolate represents the first report of Diaporthe phaseolorum associated with sunflower in the Russian Federation. The development of the stem lesions as a result of the artificial inoculation of MF 16-010 to sunflower proved that this isolate is pathogenic for sunflower.