Colletotrichum coccodes (Wallr.) S. Hughes is an important causal agent of potato black dot, but variation among isolates collected in Russia remains insufficiently characterized. In this study, 68 isolates obtained from potato tubers and stems collected in major potato-producing regions of Russia and Belarus were characterized using morphological, physiological, pathogenic, multilocus, and whole-genome approaches. The collection showed variation in colony pigmentation and sclerotial distribution, together with statistically significant differences in colony growth rate and lesion diameter in a wounded detached tuber-slice assay. Among the six isolates tested for temperature response, mean growth was highest at 25 °C among the tested temperatures and was strongly reduced at 35 °C. Multilocus sequence analysis of ITS, act, cal, and his3 loci identified five haplotypes, revealing limited sequence variation in the four loci analyzed and no obvious geographic pattern in this dataset. Comparative genome analysis of two C. coccodes isolates and one C. nigrum isolate revealed high genomic similarity between C. coccodes genomes, conserved repertoires of secreted proteins, effectors, carbohydrate-active enzymes, cytochrome P450 proteins, and secondary metabolite biosynthetic gene clusters, together with 407 orthogroups present in both sequenced C. coccodes isolates and absent from the single C. nigrum genome examined. These findings provide a comprehensive characterization of the collection of C. coccodes isolates from Russia and show that substantial phenotypic variation within the collection was accompanied by limited sequence variation in the analyzed loci, while representatives of two multilocus haplotypes remained highly similar at the whole-genome level.

Vascular bacteriosis of cabbage caused by the Gram-negative bacterium Xanthomonas campestris pv. campestris remains a significant threat to cabbage cultivation, especially in the context of stricter restrictions on the use of chemical plant protection products. The paper presents the results of characterization of the new Murka bacteriophage, which is active against 64.3% of the studied strains of the pathogen, including those circulating in Central Europe and Russia. Model experiments in a multi-channel bioreactor allowed us to determine the temperature dependence of the phage-bacterium interaction in the range of 15–45 °C. It was found that the greatest lytic activity and accumulation of phage particles are achieved at a culture temperature of 20–30 °C. This indicates the promising use of the Murka phage in various climatic zones. The phage showed resistance to chloroform, stability in the pH range of 6–10, and loss of activity at temperatures above 50 °C. Morphologically, Murka belongs to the genus Mioviruses, genetically to the genus Foxunavirus. The 43,277 bp long phage genome contains 83 ORF genes, of which 41 have a proposed function, and 42 are hypothetical proteins. Additional tests have shown that even with temperature fluctuations, the phage is able to effectively control bacterial growth. Special attention is paid to the possibility of using phage in the early stages of plant vegetation, for example, during pre-sowing seed treatment, when conditions contribute to maximum stability and effectiveness of phage therapy. In the future, it is planned to conduct in-planta tests in open ground conditions, which will determine the optimal regulations for the use and integration of phage use into a comprehensive cabbage protection system against vascular bacteriosis.

Species of the genus Epicoccum are widespread plant-associated fungi; however, their phytopathological significance in soybean remains insufficiently studied. In the present study, 15 Epicoccum isolates obtained in 2024–2026 from symptomatic soybean leaves and seeds in four regions of Russia were characterized using multilocus phylogenetic analysis, whole-genome sequencing, controlled inoculation assays, assessment of extracellular enzymatic activity, and fungicide sensitivity testing. Nine isolates were identified as E. tobaicum, five as E. mezzettii, and one as E. oryzae. The five sequenced genomes ranged from 32.84 to 34.62 Mb in size, with BUSCO completeness of 97.1–98.9%. In the mycelial-plug assay, performed without needle puncturing of the leaf blade, the largest mean necrotic lesion diameter was 12.75 ± 5.03 mm; in a separate wound-assisted assay, in which an E. tobaicum conidial suspension was applied to standardized needle wounds, the highest mean proportion of necrotic leaflet area was 26.17 ± 8.93% at 7 days after inoculation. Following artificial seed inoculation with E. tobaicum isolate 152H, no normal seedlings developed, and visible signs of fungal colonization were recorded on 100% of the seeds, indicating substantial adverse effects on seedling development under the experimental conditions. For 14 of the 15 isolates, 50% inhibition of mycelial growth by azoxystrobin was not reached at the highest tested concentration (EC₅₀ > 1000 µg/mL), indicating low sensitivity under the test conditions, whereas EC₅₀ values ranged from 0.0448 to 0.3837 µg/mL for boscalid, from 0.0760 to 0.2736 µg/mL for fludioxonil, and from 3.735 to 49.542 µg/mL for tebuconazole. These findings demonstrate substantial variation in fungicide sensitivity among the tested isolates, although further comparative studies are required to establish resistance status. To our knowledge, this study reports the first molecularly confirmed detection of E. tobaicum, E. mezzettii, and E. oryzae associated with soybean in Russia, as well as the first experimental evidence of the pathogenic potential of E. tobaicum toward soybean leaves in the country under controlled inoculation conditions. Because the conidial assay was performed on wounded leaflets, it does not establish the ability of these isolates to infect intact leaves under natural conditions.