Влияние Лазерного Облучения на Активность Бактерий Bacillus Subtilis и Pseudomonas Fluorescens

The paper discusses the problem of increasing the activity of phytopathogen-antagonistic bacteria under the effect of laser irradiation. It has been shown that short-term treatment of cells of Bacillus subtilis and Pseudomonas fluorescens with coherent light can increase bacterial growth rate and improve their fungicidal activity. It ensures high efficiency of environmentally safe measures for biological monitoring of plant diseases, which is in line with the principles of organic farming.El artículo analiza el problema de aumentar la actividad de las bacterias antagonistas de fitopatógenos bajo el efecto de la irradiación con láser. Se ha demostrado que el tratamiento a corto plazo de las células de Bacillus subtilis y Pseudomonas fluorescens con luz coherente puede aumentar la tasa de crecimiento bacteriano y mejorar su actividad fungicida. Asegura una alta eficiencia de las medidas ambientalmente seguras para el monitoreo biológico de las enfermedades de las plantas, lo cual está en línea con los principios de la agricultura orgánica.Обсуждается проблема повышения активности бактерий-антагонистов фитопатогенов под действием лазерного облучения. Показано, что кратковременная обработка когерентным светом клеток Bacillus subtilis и Pseudomonas fluorescenсs способна повысить скорость размножения бактерий и усилить их фунгицидную активность. Это обеспечивает высокую эффективность экологически безопасных мероприятий по биоконтролю болезней растений, что соответствует принципам органического земледелия

Bacteria as agents of biocontrol of phytopathogens after laser stimulation and of their metabolites’ impact on plants

The problem of increasing activity of phytopathogen antagonist bacteria under the influence of laser irradiation is considered in this paper. Studies on Bacillus subtilis and Pseudomonas fluorescens from various plant protection products have shown that use of laser irradiation leads to an increase in the number of cells in bacterial suspensions. This indicator increased to a maximum of two times at effective exposures in comparison with the non-irradiated variants. That was justification for the need to study the nature of the impact of excessive content of metabolites in the substrate synthesized by such a quantity of bacteria from biological products, which is 2 or more times higher than the number of cells in the standard solutions. With a twofold and fourfold increase in the concentration of metabolites of the studied bacteria compared to their standard content in the medium, the photosynthetic activity of cucumber microplants increased by more than 32%. This suggests that laser stimulation of bacteria – agents of biocontrol of diseases does not adversely affect the functional state of plants

Impact of coherent light on interaction of fungi and bacteria cells cultivated

This article considers impact of coherent red quasi-monochromatic light on interaction of colonies of the Pseudomonas syringae bacteria and the Fusarium macroceras fungus in an in vitro culture. A helium-neon laser and a heat source with a system of light filters and aperture diaphragms were used for irradiation. Two light fluxes were obtained with energy parameters close in magnitude, but significantly different in spatio-temporal coherence. Light with a high statistical ordering stimulated growth of both colonies. Irradiation from the same spectral range and intensity, but with low spatial coherence, increased the functional activity of only small bacteria cells. As a result, there was a suppression of larger fungal cells development that were interacting with them. Therefore, it was the statistical (coherent) properties of light that affected the change in the equilibrium of microorganisms in an artificial biocenosis. This approach can be used in practice for increasing the activity of bacteria antagonists of pathogenic fungi and the non-chemical disease protection of plants

Influence of pre-sowing red laser irradiation of tomato seeds on the initial plant development, salinity stress tolerance, and harvest yield

This work discusses the laser irradiation effects on tomato seeds (Solanum lycopersicum L), regarding the initial plant development, salinity stress tolerance and harvest yield. The aim of this study was to find an optimal pre-sowing laser irradiation treatment to enhance tomato crop.A diode laser with wavelength of 660 nm and power 100 mW was used, 16 treatments were tested by 4 power densities (0.2, 0.4, 2 and 4 mW cm-2) applied during 4 exposure times (15, 30, 60, 120 s) and a control group without treatment. The study was divided into three stages,firstly it was selected an optimal laser treatment (04 mW cm-2, 30 s), in the second stage the optimal laser treatment was evaluated under salinity stress, and finally in the third stage the optimal laser treatment was evaluated on harvest yield. The optimal laser treatment, on the initial plant development enhanced germination by 10%, radicle growth by 19%, and hypocotyl growth by 13%, in comparison to the control. On seedlings under salinity stress, optimal laser treatment promote germination up to 20%, radicle growth up to 23%, and hypocotyl growth up to 12%.According to this study, saline stress inhibits PSII activity in tomato seedlings,whereas optimal laser treatment increased PSII activity around 71%. About greenhouse crop, optimal laser treatment improved mass produced by 26%. The present study shows a path for application ofpre-sowing red laser radiation treatments in tomato seeds to improve development, saline stress tolerance and final production of tomato crop

Influence of pre-sowing red laser irradiation of tomato seeds on the initial plant development, salinity stress tolerance, and harvest yield

This work discusses the laser irradiation effects on tomato seeds (Solanum lycopersicum L), regarding the initial plant development, salinity stress tolerance and harvest yield. The aim of this study was to find an optimal pre-sowing laser irradiation treatment to enhance tomato crop.A diode laser with wavelength of 660 nm and power 100 mW was used, 16 treatments were tested by 4 power densities (0.2, 0.4, 2 and 4 mW cm-2) applied during 4 exposure times (15, 30, 60, 120 s) and a control group without treatment. The study was divided into three stages,firstly it was selected an optimal laser treatment (04 mW cm-2, 30 s), in the second stage the optimal laser treatment was evaluated under salinity stress, and finally in the third stage the optimal laser treatment was evaluated on harvest yield. The optimal laser treatment, on the initial plant development enhanced germination by 10%, radicle growth by 19%, and hypocotyl growth by 13%, in comparison to the control. On seedlings under salinity stress, optimal laser treatment promote germination up to 20%, radicle growth up to 23%, and hypocotyl growth up to 12%.According to this study, saline stress inhibits PSII activity in tomato seedlings,whereas optimal laser treatment increased PSII activity around 71%. About greenhouse crop, optimal laser treatment improved mass produced by 26%. The present study shows a path for application ofpre-sowing red laser radiation treatments in tomato seeds to improve development, saline stress tolerance and final production of tomato crop