Diaporthe species infecting sunflower in Russia

Abstract

Diaporthe is an important group of plant pathogenic fungi revealed all over the world. Early classification and species identification of this genus was mostly based on combination of morphological characteristics, cultural features, and affiliation with a host plant. According to recent investigations, valid distinction between Diaporthe species should have combined molecular techniques, morphological and cultural observations, and mating type data. In Russia a comprehensive and extensive analysis of biodiversity and geographic distribution of Diaporthe species infecting sunflower has not been performed. There were seven Diaporthe sp. strains isolated from this plant maintained in the Laboratory of Mycology and Phytopathology of All-Russian Institute of Plant Protection. In previous study a strain from Krasnodar region, based on combination of molecular and morphological features was identified as Diaporthe phaseolorum. The aim of this study was to identify all other strains using primarily molecular phylogenetic approach and traditional morphological analysis. The strains were identified as Diaporthe gulyae, Diaporthe eres, and Diaporthe helianthi. Two species - D. gulyae and D. eres are found for the first time on sunflower in Russia. Detection of D. helianthi is the first report of this fungus in Russia as confirmed by molecular analysis.