Plant Protection News (Vestnik Zashchity Rasteniy)

Tilletia fungi on wheat: biological and ecological features, distribution and harmfulness

2025-12-25T21:14:48+00:00

Smut fungi of the genus Tilletia are widespread and harmful pathogens of wheat all over the world. In the last decade, due to the expansion of organic farming zones, there has been an increase in their importance, which determines the need for increased attention to this problem. A review of the literature data on fungi of the genus Tilletia (T. caries, T. laevis, T. controversa), pathogens of common and dwarf bunt of wheat is presented. The biological and ecological features of pathogens, morphology of spores, symptoms of diseases and historical aspects of their study in Russia and abroad are analyzed. Phytopathological and molecular diagnostic methods for the causative agents of smut diseases of the genus Tilletia are discussed. The limitations of phytopathological diagnostics related to the morphological similarity of teliospores of the causative agents of hard and dwarf smut are shown. A critical analysis of the development of molecular approaches to identification has been carried out, from biochemical methods and analysis of conserved genetic loci (ITS, IGS, etc.) to methods of random genomic profiling (RAPD, ISSR, etc.), MALDI–TOF mass spectrometry, isoteric amplification (LAMP), and next-generation sequencing). Special attention is paid to the problem of insufficient specificity and reproducibility of many molecular methods, including SCAR markers. The analysis of the literature data is supplemented by original experiments of the germination of T. caries and T. controversa spores and the use of a SCAR marker to identify the pathogen of dwarf wheat smut.

Fungi associated with sunflower and their significance as pathogens in Russia

2025-12-25T21:14:47+00:00

Despite the considerable attention devoted to the study of sunflower diseases, inaccuracies in the names of diseases, assessments of their practical importance, and the use of scientific names of pathogens are still frequently encountered in the literature. This leads to confusion and reduces the informativeness of published data on the phytosanitary situation. The present review continues a series of publications dedicated to the diseases of wheat, barley, and potato. It provides structured information on the major diseases of sunflower and their pathogenic fungi, as well as on fungi that may pose a potential threat. The current taxonomic status of fungal and fungus-like organisms associated with sunflower is given, along with a brief description of their distribution and their impact on yield. The fungi are divided into two groups according to their phytosanitary significance: the first includes the pathogens of 15 major sunflower diseases, while the second comprises species associated with 13 minor or insufficiently studied diseases with unconfirmed harmfulness. Information on the potential danger of these fungi is often contradictory, and the available data appear to require further verification. The present review may serve as a reference for more accurate and consistent descriptions of the phytosanitary situation. It will also support future targeted studies employing molecular methods to clarify the taxonomy and distribution of fungi associated with sunflower and to obtain more detailed information on the harmfulness of diseases affecting this crop.

Black point in wheat: reality vs stereotypes

2025-12-25T21:14:46+00:00

The “black point “ symptom is a common discoloration of wheat and barley grain observed in most regions worldwide where these crops are grown. There are strict standards for the content of black point grains in batches of food wheat both in Russia and abroad. The mechanisms involved in the appearance of dark pigment have not yet been fully elucidated. In this study, an analysis of average samples of commercial batches of winter wheat from the Central Federal District of the 2024 harvest was carried out, where the proportion of visually detected grains with black point ranged from 4 to 27 %. According to the obtained results, the percentage of fungal infection, the taxonomic composition of mycobiota and the DNA content of the two dominant fungal groups Alternaria and Fusarium were highly similar in the fractions of visually healthy grain and grain with black point. In our opinion, this symptom is caused by abiotic environmental factors leading to physiological darkening of grain tissues, and with a high degree of certainty can be attributed to wheat diseases, the harmfulness of which has not been proven.

Assessment of antibiotic resistance in Erwinia rhapontici, the causal agent of pink grain of cereals

2025-12-25T21:14:46+00:00

The opportunistic bacterium Erwinia rhapontici causes pink bacteriosis of wheat and rye grain, significantly reducing the quality of grain products and limiting grain export. Isolation of pure bacterial culture is necessary for effective diagnostics, required for disease prevention. Presence of E. rhapontici in infected plants as a part of bacterial complex, requires selective factors, such as antibiotics. Resistance of E. rhapontici strains VNIIKR-B-0065 from Sorbus aucuparia and VNIIKR-B-0102 from Triticum durum to various antibiotics was determined. When using disks with antibiotics, the lowest inhibition level of the bacterial growth was noted in the cases of tylosin and ampicillin, which makes them promising for the selective medium. Enrofloxacin, ceftazidime, amikacin, ciprofloxacin, meropenem, cefoperazone and tetracycline statistically significantly inhibited the growth of E. rhapontici. Meropenem and enrofloxacin suppressed the growth of the pathogen the most. In liquid medium with 2,3,5-triphenyltetrazolium chloride (standard indicator of the oxidation-reduction reaction), antibiotics promising for use in the selective nutrient medium were determined and their optimal concentrations that do not affect the growth of the target bacteria were established. These are ampicillin 0.1 mg/L, bacitracin 100 mg/L, vancomycin 0.1 mg/L, kasugamycin 25 mg/L, novobiocin 2.5 mg/L, penicillin G 3 mg/L, tetracycline 50 mg/L, and tylosin 50 mg/L. A quantitative difference in antibiotic resistance was noted between the two strains of E. rhapontici, which may be due to their specific genetic properties. The results obtained laid the foundation for the study of a large number of E. rhapontici isolates to develop the final composition of the selective medium.

Prospects for using the entomopathogenic fungus Akanthomyces muscarius to protect tomatoes from pests and diseases

2025-12-25T21:14:45+00:00

This study assessed the efficacy of the entomopathogenic fungus Akanthomyces muscarius against the greenhouse whitefly Trialeurodes vaporariorum and the gray mold pathogen Botrytis cinerea. It was found that the area of B. cinerea infestation on tomato leaves was reduced after pre-treatment with conidia of two out of three A. muscarius strains. Strain Vl 61 demonstrated the greatest inhibitory effect on gray mold development. This strain, when applied to the whole tomato plants, most effectively suppressed disease development on the fourth day, with subsequent plant growth at the level of the control. When tomato leaves were infested with B. cinerea pre-inoculated with T. vaporariorum, whitefly mortality from treatment with Vl 61 spores was 69 % on the fourth day, 50 % higher than in the absence of B. cinerea. The efficacy of A. muscarius against the phytopathogen in the presence of whitefly larvae was significantly lower than on plants not inhabited by the whitefly. Fluorescence microscopy demonstrated the hyperparasitic properties of A. muscarius against B. cinerea. It was found that, when strain Vl 61* (labeled with a fluorescent tag) and the gray mold pathogen were grown together on agar medium, the fungal hyphae entwined B. cinerea hyphae, penetrating, growing, and emerging, destroying the pathogen’s cell walls. These results suggest that strain Vl 61 of A. muscarius holds promise for protecting tomatoes from B. cinerea and T. vaporariorum.

First record of Pammene blockiana (Lepidoptera: Tortricidae) in Russia

2025-12-25T21:14:45+00:00

The study reports the first record of the tortricid moth Pammene blockiana from Russia. Its males were captured in Sochi in May 2025 in pheromone traps baited with the synthetic sex pheromone of the quarantine pest, the Oriental fruit moth Grapholita molesta. A total of 48 males of P. blockiana were collected from seven traps deployed in gardens and ornamental tree plantings in Sochi. The species was identified based on morphology (forewing pattern and genitalia) and DNA barcoding. The specimens from Sochi showed low genetic variability (0.2 % among three males from three sites) and clustered with individuals from Greece, with a maximum genetic distance of 1.4 %. In DNA-barcoding fragment, Pammene oxycedrana was the closest to P. blockiana, with a minimum genetic distance of 5.4 %, followed by Pammene juniperana (7.1 %). Regular catches in the pheromone traps suggest that P. blockiana is established and potentially abundant in Sochi. As its larvae damage cones of Cupressus and Juniperus, the species may represent a potential threat to Cupressaceae in man-made plantings and nature along the Black Sea coast. New data on the species distribution and the photographs of moth and male genitalia of P. blockiana, as well as the photographs of the related moth species are provided. The species diagnosis is given to distinguish P. blockiana from closely related species associated with Cupressaceae in Europe. Possible ecological consequences and the risk of further spread of P. blockiana are discussed.

New records of the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in the southern European Russia

2025-12-25T21:14:44+00:00

The emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is a dangerous invasive pest of ashes, Fraxinus spp. Based on the results of a survey conducted in July 2025, the first record of A. planipennis in the Karachay-Cherkess Republic is reported, new foci were detected in Stavropol Territory (Mineralnye Vody region), and the locations of foci were clarified in Krasnodar Territory, including the first record of the pest in urban plantings in the city of Krasnodar. No A. planipennis presence was revealed in the Kabardino-Balkaria or Adygea republics. Of the total number of detected foci, 70 % were located in shelterbelts and roadside plantings, two foci were recorded in city parks, and one in a botanical garden. The results of the study are important for predicting the further spread of the pest in the North Caucasus.

The release of predatory bugs Orius laevigatus and Orius strigicollis (Heteroptera: Anthocoridae) against Frankliniella occidentalis on santpaulias in the Peter the Great Botanical Garden

2025-12-25T21:14:44+00:00

The predatory anthocorids Orius laevigatus and O. strigicollis were released against the Western flower thrips on Saintpaulia spp. in a greenhouse. In the winter-spring period, the thrips population decreased to 0.1 thrips per flower, and the biological efficiency was 94 and 96 % when O. laevigatus and O. strigicollis were used, respectively. In the summer, the thrips population decreased to 0.1±0.07 and 0.04±0.04 thrips per flower, and the biological efficiency was 95 % and 98 %. The efficiency depended on the season: bugs were more voracious in the summer, when the temperature was higher, which is confirmed by the observations of other researchers.

Suppression of defense response genes in the black medic to infections under conditions of effective symbiosis with arbuscular mycorrhizal fungus Rhizophagus irregularis

2025-12-25T21:14:42+00:00

The mycorrhization effect was analyzed concerning gene expression including GO:0050832 (defense reaction to fungal infection) and GO:0042742 (defence reaction to bacterial infection) groups of gene ontology under conditions of effective symbiosis in the model system “Medicago lupulina + Rhizophagus irregularis”. Massive Analysis of cDNA Ends (MACE-Seq) was applied. Under conditions of low phosphorus level, the 44 and 42 genes from defense response to the fungal and bacterial infections, respectively, were downregulated in M. lupulina leaves at the stage of 2^nd leaf development and flowering. Significantly lower expression levels of genes (orthologs Medtr1g021100, Medtr1g021110) encoding powdery mildew resistance protein RPW8 were shown during mycorrhization by the fungus R. irregularis in both the vegetative and reproductive stages of development of the plant. The role of the arbuscular mycorrhiza fungus in the formation of a nonspecific reaction to pathogenic microorganisms during the development of effective symbiosis is discussed.