Influence of artificial inoculation by strains of phytopathogenic microorganisms isolated from different sources on physyological and biochemical parameters of galega orientalis plants

Abstract

Aim. To evaluate changes in the physiological and biochemical parameters of Galega orientalis plants by the influence of artificial inoculation by phytopathogenic microorganisms, that have been isolated from various sources: strains of phytoplasmas – Acholeplasma laidlawii var granulum 118, isolated from wheat and Acholeplasma laidlawii 101 and 178, isolated from tomato and bacterial strain – P. syringae pv. atrofaciens D13, which have been isolated from wheat.Methods. Microbiological methods – cultivation in the liquid nutrient medium, isolation of phytopathogenic microorganisms from plant material and artificial inoculation of experimental plants (subepidermal injection); biochemical – for the purpose of determination of photosynthetic pigments – chlorophylls a and b and carotenoids and activity of antioxidant enzymes catalase and peroxidase; photochemical – method of chlorophyll a fluorescence inducing to determine the photochemical activity of leaves; biometric – to determine the area of the root system and the number of nodules on the roots; statistical.Results of research. In field experiments on the crops of the Fodder Galega under the conditions of artificial infection with strains of phytopathogenic microorganisms of different taxonomic groups – A. laidlawii var. granulum 118 and P. syringae pv. atrofaciens D13 (both isolated from wheat) and strains – A. laidlawii 101 and 178, isolated from tomatoes, the following changes were observed in the physiological and biochemical parameters of Galega orientalis plants: reduction of chlorophyll a and b content with increasing carotenoid content and inhibition of quantitative efficiency of PSII, especially in mixed A. laidlawii var. granulum 118 and P. syringae pv. atrofaciens D13, which was accompanied by a decrease in the area of the root system and the number of nodules on the roots of the plants. It was found, that the highest total activity of tissue Galega orientalis oxidase reductases – catalase and peroxidase was observed at inoculation with strains, isolated from wheat. The crude protein content of goat leaves was found to be lower at inoculation with strains, isolated from wheat than at inoculation with strains, isolated from tomatoes.Conclusions. 1. By artificial inoculation, all investigated strains of pathogens revealed a decrease in the content of chlorophyll a and b, but most significantly – phytoplasma content of chlorophyll a has been decreased. The carotenoid content increased with respect to intact plants at inoculation of plants with phytopathogenic strains in the following consistency: 101+118>118>118+D13>178.2. It was found, that at inoculation of Galega orientalis with phytopathogenic strains, isolated from wheat: inoculation with phytoplasma (monoinoculation) and especially – mix of strains: phytoplasma and bacterial, along with a decrease in the quantitative efficiency of PSII, an induction coefficient increased, which is probably caused by an increase in photorespiration or the acceptor action of phytopathogens.3. It was found, that the highest total activity of Galega orientalis leaf catalase and peroxidase was observed at inoculation with strains, isolated from wheat – phytoplasma (monoinoculation) and mix of inoculation – phytoplasma and bacterial strains.4. Suppression of the functional activity of the leaves for the destruction of the pigment-protein complexes of PS II at inoculation of phytopathogenic strains led to morphological changes – significant decrease in the area of the root system and the number of nodules: phytoplasma (monoinoculation) and mix phytoplasma and bacterial strains.5. It was shown, that at inoculation with phytopathogenic strains, isolated from wheat: phytoplasma and bacterial inoculation mix and especially – the mono-inoculation of phytoplasma, the crude protein content in the leaves was less than the monoinoculation phytoplasma strain, isolated from tomatoes (178) and at mix inoculation phytoplasma strain, isolated from tomatoes and wheat (101+118)