Resistance of modern spring barley cultivars to harmful organisms

Background. Diseases and pests cause great damage to barley stands and harvests. Harvest losses from harmful organisms reach 25–30%.Materials and methods. During 2017–2020, 46 spring barley cultivars from the VIR collection, listed in the State Register for Selection Achievements, were studied for their resistance to fritfly, net and spot blotches, brown rust, and powdery mildew. The tests were carried out in the field with provocative colonization by fritfly and under natural infection pressure of leaf pathogens.Results and conclusions. In 2017, net blotch predominated over other diseases. In 2018, there was an epyphytotic outburst of spot blotch, and cultivars with weak development of this disease were identified. In 2019 and 2020, the incidence of brown rust and powdery mildew was significant, and the virulence of fritfly increased greatly in the same years. Field tests resulted in identification of 3 barley accessions resistant to fritfly: ‘Odon’ (k-31118, Buryatia), ‘Miar’ (k-31203, Orenburg Province), and ‘Omsky 99’ (k-31230, Omsk Province). Cv. ‘Posada’ (k-31245, Germany) was weakly affected by fritfly, brown rust and powdery mildew. Cultivars were selected for their low susceptibility to powdery mildew (up to 5%): ‘Chiraz’ (k-31131, Denmark), ‘Cheerio’ (k-31297, Denmark), and ‘Odyssey’ (k-31333, England), and brown rust: ‘Chiraz’ (k-31131, Denmark), ‘Eifel’ (k-31249, France), ‘Ursa’ (k-31339), and ‘Sunshine’ (k-31129, Germany). Such long-term assessment results can be used in breeding programs to develop cultivars with group or complex resistance to harmful organisms.

Influence of meteorological conditions on the residual content of pesticides in plants

The quality and quantity of agricultural products depends on the weather conditions in the regions of cultivation. The results of the influence of weather on the degradation rate of pesticides in agricultural products are presented in this paper. Samples were analyzed for the content of pesticide active ingredients by various chromatographic methods. Air temperature has a significant effect on the intensity of metabolic processes in the plant, which determine the degradation rate of pesticides. Air humidity is more important for water-soluble pesticides than for lipophilic ones. Rain, moisture and dew accelerate the dispersal of substances from the aboveground plant parts. When choosing pesticides to protect crops from harmful organisms, it is necessary to take into account the natural and climatic characteristics of the region.

Phenotypic and DNA Marker-Assisted Characterization of Russian Potato Cultivars for Resistance to Potato Cyst Nematodes

Potato is one of the most important food crops in the world and also in the Russian Federation. Among harmful organisms reducing potato yield potential, the potato cyst nematodes (PCN) are considered to be ones of the most damaging pests. Information on PCN resistant cultivars is important for potato breeding and production. Russian potato cultivars are characterized in the state-bio-test program for resistance to only one PCN species Globodera rostochiensis and one pathotype Ro1 which is reported to be present in the country. This study aimed to find domestic cultivars with multiple resistances to different PCN species and different pathotypes using phenotyping coupled with molecular marker analysis due to the risk of the occasional introduction of new pests. The phenotypic response was determined by the inoculation of plants with pathotypes Ro5 of G. rostochiensis and Pa3 of G. pallida. The obtained results were supplemented by the state-bio-test data on resistance to Ro1 of G. rostochiensis. Nine of 26 Russian cultivars were resistant both to Ro5 and Ro1 pathotypes and two cultivars possess multiple resistances to both PCN species. Most tested molecular markers associated with the Gpa2, GpaVvrn, GpaVsspl, Grp1 loci showed discrepancies with phenotyping. However, a predictive haplotype and epistatic effect were detected.

Antifungal and Insecticidal Potential of the Essential Oil from Ocimum sanctum L. against Dangerous Fungal and Insect Species and Its Safety for Non-Target Useful Soil Species Eisenia fetida (Savigny, 1826)

The antifungal and insecticidal effect of the essential oil from Ocimum sanctum L. was evaluated using a model set of harmful organisms hazardous for health and the economy. Toxigenic and plant pathogenic filamentous fungi, including causal agents of human infections, were chosen as exemplary fungal groups—Fusarium verticillioides, Penicillium expansum and Aspergillus flavus. Spodoptera littoralis (African cotton leafworm), Culex quinquefasciatus (Southern house mosquito), the lymphatic filariasis vector and potential Zika virus vector, and the common housefly, Musca domestica were chosen as model insects. Major and minor active substances were detected and quantified using GC/MS analysis. Environmental safety was verified using the non-target useful organism Eisenia fetida. Significant antifungal and insecticidal activity, as well as environmental safety, were confirmed. The essential oil showed the highest efficacy against A. flavus according to MIC50/90, and against S. littoralis larvae according to LD50/90. The monoterpenoid alcohol linalool, t-methyl cinnamate, and estragole as phenylpropanoids were detected as effective major components (85.4%). The essential oil from Ocimum sanctum L. was evaluated as universal and significantly efficient, providing a high potential for use in environmentally safe botanical pesticides.

Phytosanitary monitoring of the narrow-leaved lupine collection of VIR in the northwest of Russia

Background. Narrow-leaved lupine (Lupinus angustifolius L.) is an important high-protein forage and green manure crop, also promising for food use. This is a plastic species produced under various ecogeographic conditions and the only cultivated species of lupine adapted to high northern latitudes – up to 60° NL. Gradual expansion of lupine production areas led to the accumulation of pathogens, damage to lupine crops by harmful organisms, and significant harvest losses. Breeding and cultivating resistant varieties is the most profitable and environmentally sound way to control diseases and pests. Studying the species composition of pathogens and searching for source material are the necessary stages of plant breeding for immunity.Materials and methods. A set of 101 accessions of L. angustifolius from the VIR collection were studied in the northwest of the Russian Federation (Pushkin, St. Petersburg) in 2019, and 62 accessions from the same set in 2020. Mycological examination of the affected leaves was carried out on potato sucrose agar medium under laboratory conditions. The degree of damage to plants by diseases and infestation by pests was assessed during the period of flowering, fruit formation and ripening using point scales.Results and conclusions. A wide range of harmful organisms were identified for their negative impact on the growth and development of narrow-leaved lupine plants. The dominant pest was the lupine aphid (Macrosiphum albifrons Essig), discovered in Russia for the first time. A whole set of fungal pathogens was identified, among which the most common and harmful were the causative agents of Fusarium, brown leaf spot, powdery mildew, gray mold, and Sclerotinia stem rot. Narrow-leaved lupine accessions with weak degrees of pathogenic damage were selected.

Investigations on invasive nematodes associated with complex insect pests from soil in corn in the environmental conditions of the Republic of Moldova

Corn is one of the major technical field crops in the Republic of Moldova, advantageous in bioecological and productive aspects, which is invaded annually by the harmful organisms with considerable parasitic impact. The phytosanitary control results, carried out annually and seasonally, comparatively in the corn plantations, notice a significant diversity of the specific diseases and of the invasive insects that seriously affect the plants from the germination phases until the harvest. In corn, were established the numerical density values (D. n.), comparative in different ecological areas, on average 15-280 (ex. /100 g soil), with an abundance by 5-25% higher in the autumn than in the spring. Phytoparasitic impact indices the frequency (F %) and intensity (I %) of the phytohelminthological disease level was estimated, being more advanced by 3-30% in the spring-summer period, observed differently depending on the area compared to the autumn period. The structure of parasitic phytonematode complexes was determined counting 20 species, included in 8 families and one order (Tylenchida), classified according to trophic specialization, with the predominance of endo-ectoparasites. It was established the diversity of the associated invasive insect species from the soil: 12 species, 8 families, 3 orders, also, with invasive ectoparasitic impact on corn plants, with the disease degree of 5-40%, detected in all phases of vegetation and sectors investigated.

How Phagocytes Acquired the Capability of Hunting and Removing Pathogens From a Human Body: Lessons Learned From Chemotaxis and Phagocytosis of Dictyostelium discoideum (Review)

How phagocytes find invading microorganisms and eliminate pathogenic ones from human bodies is a fundamental question in the study of infectious diseases. About 2.5 billion years ago, eukaryotic unicellular organisms–protozoans–appeared and started to interact with various bacteria. Less than 1 billion years ago, multicellular animals–metazoans–appeared and acquired the ability to distinguish self from non-self and to remove harmful organisms from their bodies. Since then, animals have developed innate immunity in which specialized white-blood cells phagocytes- patrol the body to kill pathogenic bacteria. The social amoebae Dictyostelium discoideum are prototypical phagocytes that chase various bacteria via chemotaxis and consume them as food via phagocytosis. Studies of this genetically amendable organism have revealed evolutionarily conserved mechanisms underlying chemotaxis and phagocytosis and shed light on studies of phagocytes in mammals. In this review, we briefly summarize important studies that contribute to our current understanding of how phagocytes effectively find and kill pathogens via chemotaxis and phagocytosis.

Microbiota Management for Effective Disease Suppression: A Systematic Comparison between Soil and Mammals Gut

Both soil and the human gut support vast microbial biodiversity, in which the microbiota plays critical roles in regulating harmful organisms. However, the functional link between microbiota taxonomic compositions and disease suppression has not been explained yet. Here, we provide an overview of pathogen regulation in soil and mammals gut, highlighting the differences and the similarities between the two systems. First, we provide a review of the ecological mechanisms underlying the regulation of soil and pathogens, as well as the link between disease suppression and soil health. Particular emphasis is thus given to clarifying how soil and the gut microbiota are associated with organic amendment and the human diet, respectively. Moreover, we provide several insights into the importance of organic amendment and diet composition in shaping beneficial microbiota as an efficient way to support crop productivity and human health. This review also discusses novel ways to functionally characterize organic amendments and the proper operational combining of such materials with beneficial microbes for stirring suppressive microbiota against pathogens. Furthermore, specific examples are given to describe how agricultural management practices, including the use of antibiotics and fumigants, hinder disease suppression by disrupting microbiota structure, and the potentiality of entire microbiome transplant. We conclude by discussing general strategies to promote soil microbiota biodiversity, the connection with plant yield and health, and their possible integration through a “One Health” framework.

The River Influence Controls Water Quality and Spatio-Temporal Microalgal Distribution in Pacific Estuaries (Padre Ramos and Salinas Grandes) of Nicaragua

Estuaries are coastal wetlands that deserve special attention because they are vulnerable, biodiversity- and service-rich environments. However, estuaries of tropical areas have been scarcely studied regarding water quality and biodiversity in spite of strong developments of their agricultural and livestock sectors. Two estuaries on the Pacific Nicaragua in which snapper cages had been set up were studied regarding water physicochemical properties, microalgae and cyanobacteria along with their dynamics over a hydrological year. Both environments showed excellent water quality (oligotrophy and absence of harmful organisms) arising from their fluvial features. During the rainy season, there was a decline in chemical compounds and microorganisms. In the dry period nutrients and salinity promoted different assemblages of microscopic primary producers that were never too dense. Nutrient inputs from shrimp farms, agricultural crops and snapper cages did not appear to increase eutrophication and cyanobacterial blooms did not occur. Furthermore, the strong fluvial character of these estuaries seems to prevent the entry of harmful dinoflagellates from marine areas.

The Lactic Acid Bacteria in Fermented Durian (D. Zibethinus )

Lactic acid (C2H5COOH) is the organic acid that can serve as a food preservation. The group of bacteria which can produce lactic acid in their fermentation process known as Lactic Acid Bacteria (LAB). A fundamental biochemical change of fermentation is that an acidic environment is created. Many harmful organisms cannot exist in acidic solution so the fermentation productions are save to eat. Fermented Durian is the fermented food prepared from spontaneous fermentation of durian (Durio zibethinus) with or without salt by wild bacteria. The research was conducted to isolate and identify lactic acid bacteria in tempoyak. The data in this study were laboratory analysis. Samples were collected weekly in a month analyzed microbiologically from traditionl markets in Bengkulu. There were four species of lactic acid bacteria involved in fermented durian namely Leuconostoc mesentroides, Pediococcus acidilactici, Lactobacillus plantarum, and Lactobacillus curvatus.