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Spychak, V.

Publications and source records attributed to Spychak, V..

2 recordsLinked to original sources
bioRxiv2024

CONTROL OF OROBANCHE CUMANA WALLR: RESEARCH ON SUSTAINABILITY OF SUNFLOWER HYBRIDS AND STRATEGIES FOR PARASITE PROTECTION

The work is devoted to solving an important scientific task of determining the spread and harmfulness of broomrape, its racial composition, and developing measures to protect sunflower from this parasite. The aim of the research was to determine the resistance of sunflower hybrids to the broomrape parasite. During the research, a vegetation experiment was used to determine the racial composition of the parasite and the resistance of different sunflower hybrids to it. Sunflower hybrids were evaluated for resistance to broomrape in soil culture using a modified method and the roll method of seed germination. From the northern Steppe of Ukraine, broomrape is actively moving to the central, northern and western regions of the country. The practical value of the work is to determine the resistance of sunflower hybrids to broomrape. Differentiation of sunflower hybrids grown by resistance to the parasite was carried out. It has been observed that the broomrape population exhibits a significant level of virulence capable of overcoming the immunity found in the most resilient foreign-bred hybrids resistant to E, F, and G races of this parasite. The appearance of highly aggressive new races of broomrape (E, F, G, and H) in the Forest-Steppe and Polissya regions underscores the crucial necessity to address the challenge of developing breeding material resistant to these novel races of the parasitic plant. This entails an in-depth exploration of the cellular and molecular mechanisms underlying sunflower resistance to the pathogen. The widespread buildup of parasite races E, F, G, and H in sunflower crops is linked to the disruption of crop rotations and the extensive cultivation of hybrids of this crop. These hybrids are primarily resistant to races 5 (E) and 6 (F) of the parasite. The results of the research can be used in the regions farms for successful protection against broomrape, as well as in breeding programs to create sunflower hybrids resistant to new races of the parasite and corn hybrids that cause better germination of seeds of this pathogen in the soil and their death by their root secretions.

plant biology↗
bioRxiv2024

HEMIBIOTROPHIC INFECTION OF SUNFLOWER ROOT CELLS BY THE PARASITE OROBANCHE CUMANA WALLR.

The process of infection of different sunflower hybrids by Orobanche cumana was studied according to the way the pathogen interacts with the components of root cells. The study of the behavior of sunflower root cells during the penetration of Gaustoria showed not biotrophic, but hemibiotrophic process of infection of hybrids with the pathogen. In the hemibiotrophic mixed type of sunflower infection, broomrape initially develops as a biotrophic pathogen and, with the help of effectors, suppresses the course of immune reactions and forms multicellular haustoria, which at a certain stage of growth break the membrane bags of cells, leading to cytoplasmic leakage and causing the death of root cells as a necrotrophic pathogen. The discovery of the hemibiotrophic process of sunflower broomrape infection opens a new promising direction in reducing the infection of hybrids with the parasite through the induction of systemic acquired resistance (SAR) by drugs that cause the formation of reactive oxygen species and trigger plant defense responses through programmed cell death at the sites of infection and cause pathogen necrosis. The process of infection of cells and the emergence of reverse immune responses in plants when infected with pathogens has similar features and a similar course of protective responses. In the interaction between broomrape and sunflower, resistance mechanisms may act to stop the pathogen in the root cortex, in the entodermis, or after reaching the central cylinder. The cell wall is the first obstacle that pathogens have to overcome. The cell membranes of growing cells have a "primary" structure. Cell walls are composed of cellulose and matrix substances (hemicelluloses, pectins, and proteins). In cells that have already formed, the cell walls are reinforced with lignin, suberin, and kalose. Sunflowers defense reactions against broomrape consist of strengthening the cell wall through the deposition of lignin, suberin, accumulation of callose, protective proteins and cross-linking of proteins that prevent the parasite from penetrating and communicating with the host vascular system. Lignin, suberin and callose polymers strengthen the cell wall structure by increasing its stiffness at the site of infection to limit the penetration of the parasite.

plant biology↗