Kryuchkova L. Diseases of winter wheat caused by necrotrophic fungal pathogens and methods for their diagnosis

The system of diagnosis of winter wheat diseases caused by necrotrophic fungal pathogens is presented in the thesis. Descriptions of visual symptoms of each root and stem base disease form the basis of an original guide presented as two dichotomous keys to disease identification at seedling and adult growth stages. The methods for isolation of the causal agents of take-all, eyespot and sharp eyespot, as well as for their artificial inoculation on wheat seedlings, were improved. This is an important prerequisite for research on populations of the pathogen, their changes and control. Using the methods established for disease diagnosis, pathogen isolation and artificial inoculation, interactions between necrotrophic fungal pathogens wheat plants were investigated. It was established that the individual pathogens differ in their degree of physiological specialization. The physiological reactions of wheat plants after infection by necrotrophic fungal pathogens, as well as after treatment by plant growth regulators of natural origin, were investigated. It was found that the characteristics of these reactions depended on the pathogen species and the nature of preparation. It was shown that mechanical structures - papillae - can be used as markers for resistance of wheat seedlings to eyespot. The possibilities for using plant growth regulators in mixtures with fungicides for seed treatment of wheat were studied. It was established that their effects depend on determining the correct ratio of components.