Phylogenetic Study of Alternaria Potato and Tomato Pathogens in Russia

Early blight (EB) is a destructive disease affecting potato and tomato plants in Russia, caused by a heterogeneous group of plant pathogenic Alternaria fungi. The current species delimitation in Alternaria sect. Porri with medium to large conidia and a long (filamentous) beak is based on molecular data. In this study, the ITS, GAPDH, RPB2, TEF1, and Alt a 1 gene regions were analyzed in 41 large-spored Alternaria isolates obtained from diseased potato and tomato plants collected from 13 regions in Russia. Our data revealed five pathogenic species (A. alternariacida, A. grandis, A. linariae, A. protenta, and A. solani). Two species (A. solani and A. linariae) were found to be associated with early blight of tomato. Alternaria linariae and A. protenta were confirmed as the major causal agents of tomato and potato early blight, respectively. There were no phylogenetic groupings among tested Russian Alternaria isolates associated with their locality

Phylogenetic Study of <i>Alternaria</i> Potato and Tomato Pathogens in Russia

Early blight (EB) is a destructive disease affecting potato and tomato plants in Russia, caused by a heterogeneous group of plant pathogenic Alternaria fungi. The current species delimitation in Alternaria sect. Porri with medium to large conidia and a long (filamentous) beak is based on molecular data. In this study, the ITS, GAPDH, RPB2, TEF1, and Alt a 1 gene regions were analyzed in 41 large-spored Alternaria isolates obtained from diseased potato and tomato plants collected from 13 regions in Russia. Our data revealed five pathogenic species (A. alternariacida, A. grandis, A. linariae, A. protenta, and A. solani). Two species (A. solani and A. linariae) were found to be associated with early blight of tomato. Alternaria linariae and A. protenta were confirmed as the major causal agents of tomato and potato early blight, respectively. There were no phylogenetic groupings among tested Russian Alternaria isolates associated with their locality

Fungal diversity in tomato (Solanum lycopersicum) leaves and fruits in Russia

Sequencing of cloned PCR-amplified species-specific rDNA fragments and isolation of axenic cultures from tomato fruits was carried out to study the mycobiota of tomato leaves and fruits in European part of Russia. DNA was extracted from the leaves, and library of ITS region fragments was constructed in E. coli by cloning of PCR products. This survey revealed fourteen species associated with disease-affected leaves: Septoria lycopersici, Fulvia fulva (=Cladosporium fulvum), Didymella glomerata (=Phoma glomerata), Cladosporium herbarum, Podosphaera fusca, Neocamarosporium goegapense (=Phoma betae), Rhizoctonia solani, Candida albicans, Dioszegia hungarica, Cladosporium cladosporioides, Didymella lycopersici, Alternaria infectoria, Alternaria alternata, Cryptococcus tephrensis. In the leaves from healthy plants without any visible symptoms DNA of three species was found: Aspergillus versicolor, Alternaria alternata, Aureobasidium pullulans. Analysis of axenic cultures isolated from green diseased tomato fruits revealed fungal species: Alternaria alternata, Alternaria solani, Phomopsis phaseoli, Fusarium equiseti, Chaetomium cochliodes, Clonostachys sp., Irpex lacteus, Colletotrichum coccodes. This research provides new information on the mycobiota of tomato in Southern Russia, the main tomato producing region of the country. © 2020, University of Zagreb - Faculty of Agriculture. All rights reserved