Експресний метод діагностики грибних захворювань соняшника (Helianthus annuus L.)

Abstract

This work is devoted to development of early diagnosis methods of fungal diseases in agricultural plants, which will increase effectiveness of protective measures against them. For today, there are many diagnosis methods of diseases and identifying fungal pathogens. These diagnosis methods of diseases allow the identification of fungal pathogens only after the beginning of development the pathological process. In such cases it is not able to protect the plants in time. Found that in the early stages of the disease, which is still impossible to identify visually, the first changes, are happening in the processes of photosynthesis and can be fixed. Chlorophyll fluorescence is the only indicator that allows studying the photochemical reactions in live objects that are connected with work of photosystem II (FS2) of Streptophyta plants. However, these methods will not allow identified of fungal diseases in agricultural plants. The aim of study is developing an express method for early sunflower fungal diseases diagnosis by modifying the methods for recording induction of chlorophyll fluorescence and fluorescence microscopy. Research objects were sunflower Helianthus annuus L. With the aim of identifying the state of photosynthetic apparatus are evaluated changes in the functioning of photosynthetic processes in sunflower leaves Helianthus annuus L. The investigation was conducted on fluorescent photoinduced indicators basis. Definition of fungal disease and assessment of its impact as a stress factor, they were conducted by comparison informative indicators of chlorophyll fluorescence induction of experimental plants. We investigated the interconnection between the changes of chlorophyll fluorescence induction parameters and the presence of fungal diseases in plants that didn`t have visual damage to viruses and diseases. In the process of performance work were conducted the expert research of chlorophyll fluorescence. The results of the study were monitored by light microscopy. In the process of performance work, we found that all investigated plants were characterized by a uniform emission of red fluorescence intensity. Absence of differences in the intensity of fluorescence doesn`t make it possible to determine the presence of fungal infection. With the aim of detecting hidden fungal infection. We have developed method of temperature influence on the plant leaves during the research. As a result, of the influence of temperatures on the leaves of individual plants were recorded flashes of yellow-green fluorescence. In these plants the fungal disease was detected visually by light microscopy in 12-18 days later and it was identified as Phomopsis helianthi M. The proposed modification of the method of photoinduction fluorescence in combination with the luminescent microscopy method have allowed to detect the presence of hidden fungal infection in annual sunflower at the earliest stages of its development. Perspective of the further development of this method for the purpose of early diagnosis of the presence of hidden infection in various agricultural plants. Keywords: annual sunflower, fungal diseases, diagnosis, fluorescence induction of chlorophyll, Phomopsis helianthi M.