Abstract. Sustainable plant development, i.e. maintenance of its phenotype in conditions of changing environmental parameters or genetic deviations, is realized by a set of mechanisms, generally characterized by developmental stability. The most striking manifestation of the stability of the development of the biological object at the macro level is the effect of fluctuating asymmetry (FA). The lighting conditions, along with other environmental factors, affect both the productivity of the plant and the stability of its development. The issues that remain scarcely studied are the influence of lighting conditions and plant variety on the FA level. One of the widely used and informative parameters is the chlorophyll content in plant leaves and their size. The aim of the study is to confirm the hypothesis of the effect of differences in the light quality and plant variety on the level of FA of the symmetrical plant structures. The object of the study is the leaves of tomato plants grown in an industrial greenhouse. The measurements were carried out in the greenhouse of Mezvidi, Latgalia, for three variants: tomato variety orange Bolzano F1 grown under high-pressure sodium lamps (HPS) and LED sources, and the red Encore F1 grown under HPS. As a result of the experiments, the presence of a significant asymmetry of the bilateral structures of tomato leaves was detected by their size and chlorophyll content. The fluctuating nature of asymmetry is proved. It was revealed that the influence of the type of the light source and tomato variety on FA on the basis of certain traits is multidirectional. For the tomato variety Bolzano, the level of FA on the basis of the leaflet size is 66 % higher under HPS compared to the LED, and on the basis of the chlorophyll content does not depend on the type of the light source. For HPS the level of FA on the basis of the leaflet size is 24 % higher at Bolzano compared to Encore, and on the basis of the chlorophyll content, it is 28 % lower.Keywords: developmental, stability, plant, lighting, energoecology. IntroductionEffective cultivation of plants in artificial conditions is possible only using the indoor plant lighting technology with supplemental light sources. Light is one of the factors that affect the concentration of phytochemical compounds [1]. Sustainable plant development, i.e. maintenance of its phenotype in conditions of changing environmental parameters or genetic deviations is realized by a set of mechanisms, generally characterized by stability of development. The most striking manifestation of the stability of the development of the biological object at the macrolevel is the fluctuating asymmetry (FA), which consists in minor and random deviations of the parameters of bilateral (mirror) traits. It was revealed that the relationship between stress factors and the stability of development is not obvious. A number of researchers note an increase of the FA level under stress, while others do not confirm a statistically significant relationship [2]. Under favourable environ...

Abstract. Under the influence of radiation energy the plants feature a number of physical effects, which lead to regulatory and other processes, up to gene expression. Single photons of irradiation absorbed by plant organisms initiate quick and visible transformation of the morphological and physiological state of plants. The most striking manifestation of developmental stability of a biological object at macro level is fluctuating asymmetry, which involves slight and random deviations in bilateral (mirror) traits. The fluctuating asymmetry is known to be minimal only under optimal environmental conditions but it increases under any stress conditions. If non-optimal irradiation parameters, affecting the plants, are considered a stress factor, the fluctuating asymmetry level may be taken as an indicator of the plant status for assessment of effectiveness and sustainability of the plant growing process under artificial conditions. We conducted several studies to identify the relationship between the level of fluctuating asymmetry of forcing parsley leaves (Petroselinum crispum var. tuberosum) and the light quality of different radiation sources. Two sources with equal photosynthetic photon flux density of 80 µmol . m -2. s -1 in the growing zone were used: a LED irradiator, with the ratio of radiation density (blue k B 400-500 nm, green k G 500-600 nm and red k R 600-700 nm) being k B : k G : k R = 31 % : 9 % : 60 %, and high pressure sodium lamps with the ratio of k B : k G : k R = 9 % : 54 % : 37 %. The length of the first leafstalks of the first order extending from the rachis was considered as a bilateral trait. The size-dependence of this trait was not found. Statistical analysis of the (L-R) variant distribution by the Wilcoxon test showed the fluctuating type of asymmetry. The effect of irradiation light quality on the leaf fluctuating asymmetry level was revealed. The higher fluctuating asymmetry level was found to correspond to smaller values of parsley productivity.Keywords: phytomonitoring, indoor plant lighting, light quality, developmental instability, fluctuating asymmetry, Petroselinum crispum var. tuberosum. IntroductionThe flow energy in the range of photosynthetically active radiation (PAR) with a wavelength from 400 to 700 nm is the basis of the indoor plant lighting, i.e. growing plants under artificial light sources. In order to maximize the productivity of cultivated plants with the minimum energy inputs an additional artificial optical radiation is used. It provides an opportunity to vary many radiation parameters, such as intensity, duration, light quality, etc. The latter has an essential effect on the growth, development and physiology of plants [1].Under the influence of irradiation energy the plants feature a number of physical effects, which lead to regulatory, adaptive and other processes, up to the gene expression. Single photons of irradiation absorbed by plant organisms initiate quick and visible transformation of the morphological and physiological condition of plants [2].As a liv...

To develop the theory and practice of operation procedures in a greenhouse, a mathematical model of indoor plant lighting is required. (Research purpose) Development of a simulation and analysis technique of energy-and-ecological compatibility of indoor plant lighting. (Materials and methods) The authors experimentally verifi ed the proposed technique for the indoor plant lighting of tomato seedlings grown under laboratory conditions with controlled environmental parameters. An irradiator consisting of a LED matrix with secondary optics and a driver was used. The photoperiod amounted to 16 hours. The experiment was completed for 46 days. The technique includes an analysis of the energy conversion effi ciency at various stages in the blocks of the artifi cial bioenergy system of indoor plant lighting (ABES): a source of electrical power; a radiation source; an optical part; spatial fl ow distribution; surface fl ow distribution; and a plant. The authors proposed formulas for calculating the energy consumption of each ABES unit. It was revealed that for the estimated values of the energy consumption of ABES blocks taken according to expert estimates, the total energy consumption accounts for 0.32-2.27 megajoule per one gramme of wet weight of a plant, i.e. diff ers by almost an order of magnitude, depending on the specifi c implementation of the lighting technology. It is shown that optimization cannot be limited by consistent selection of an option with the lowest value of energy consumption at each stage, but requires fi nding the optimal route on the graph of options. (Results and discussion) For the experimental conditions, the total energy consumption of ABES was 3.77 megajoule per one gramme of the wet weight of a plant. The low effi ciency was caused by the unsatisfactory effi ciency of the LED matrix and the low productivity of the plant photosynthesis. (Conclusions) The developed technique for modeling and analyzing the energy-and-ecological compatibility of indoor plant lighting allowed assessing possible energy saving at each stage of energy and substance conversion in indoor plant lighting. Theoretically, possible reduction of losses in the source of electrical power is 22 percent, in the optical part – 14 percent; in spatial fl ow distribution – 16 percent; in surface fl ow distribution – 10 percent. Possible increasing of the lighting source effi ciency depends on the achieved level of technology, which currently provides an output of 2.5 micromole per joule and more. To increase the productivity of indoor plant lighting, it is necessary to precisely match the parameters of the lighting mode and the requirements of plants.

No abstract

The purpose of this work is to develop a method for assessing the stability of plant development by using the fluctuating asymmetry of the optical density of plant leaves and to design a device for experimental implementation. The paper reviews existing methods and devices for estimating the fluctuating asymmetry by linear and angular dimensions, where the main disadvantages are the high labour inputs and lack of the required functions. It is shown that the optical densities of half-leaves can act as the bilateral traits, by which the stability of plant development can be assessed. The developed method allows to give a comprehensive assessment of energy and ecological compatibility of indoor plant lighting. The hardware component of the device allows to form the vectors of the radiation fluxes incident and transmitted through the leaf for each leaf half in the blue, green and red spectral bands. The experimental model of the device contains an integrating sphere with a photo resistor, measuring the irradiation of the inner surface. Control program is executed on the Arduino Uno microcontroller board based on the Microchip ATmega328P. The measured data are displayed on LCD screen (Keypad Shield) and stored in the external memory (SD card). Colour LEDs are used as the radiation source. The control program provides calibration modes, measurement of optical density and measurement of fluctuating asymmetry of the optical density in three spectral bands. The device was tested on vegetable marrow plants grown in laboratory conditions under light sources with different light quality. The differences in the optical density and fluctuating asymmetry in separate spectral bands were found to be statistically significant for plants grown under different light sources. The designed device provides wide opportunities for rapid assessment of the plant state by the pigment content in leaves. In the presence of appropriate experimental data, it is possible to find a correlation between the values of the optical density of the leaves and other biometric parameters of the plant.