Intensity Of Photosynthesis Research Articles

Особливості трансформації фітопланктону Житомирського водосховища (р. Тетерів, басейн Дніпра, Україна)

Stable functioning of the ecosystem of the Zhytomir reservoir, which is indicated by the absence of directed changes in the primary production over a long period, is pro­bably supported by the alterations of the algae groups at the level of their structure, by the high speed of incorporation of organic matter into the bio-water cycle, and by large areas of water levels. Over the last 10 years, the role of blue-green algae has decreased in the taxonomic composition of the phytoplankton of the Zhytomir reservoir, while the species richness of green, euglenic and golden ones has increased; there were minor alterations to the phytoplankton structure at the class level and more noticeable changes at the order, family, and birth levels. Over a period of almost ten years the species saturation of the genus Chlamydomonas Ehrenb., Euglena Ehrenb., Cyclotella Kützing., Peridinium Ehrenb. Generally, the generic coefficients and the saturation of species with intraspecific taxa increased (which was also observed for the small Denyshivske reservoir), whereas for large reservoirs of the Dnipro and Volga there is a tendency to simplify the taxonomic structure of phytoplankton with their age. Phytoplankton biomass indicators remained unchanged for almost ten years, however, there was a shift in biomass peaks from summer to autumn. The number of algae cells decreased. Phytoplankton alignment decreased. Inadequacy has been established in the trophic status of the Zhytomir Reservoir, determined by biomass and primary phytoplankton production. The higher trophic level, determined by the intensity of photosynthesis, is probably due to the predominance in the dominant complexes of small-cell highly productive species that support the high trophic status of aquatic ecosystems with relatively low phytoplankton biomass. At the present stage, there is a tendency to improve the water quality of the reservoir according to the saprobiological indicators of phytoplankton development in comparison with 2003–2007.

Effects of hydrothermal conditions on agrophysical properties of typical chernozem and crop rotation productivity in the system of organic farming

Relevance of research. Having the variability of hydrothermal conditions, the rate of plant life, the intensity of photosynthesis and evaporation and the activity of plant nutrient consumption change. As a rule, the optimization of the water-air regime of the soil by conducting various types of amelioration makes it possible to significantly reduce the negative effects of adverse weather conditions and ensure high sustainability of agroecosystems. However, with regard to the requirements for organic agriculture in the regions with a shortage of water supply without sufficient water resources and without the use of fertilizers to effectively conduct agricultural production is problematic. Thus, the establishment of the patterns of the dynamics of agrophysical soil properties, taking into account their impact on the bioproductivity of agrophytocenoses under variable weather conditions is the theoretical basis for solving the problem of increasing agricultural sustainability, in particular using only natural fertility and obtaining organic crop products.
 Purpose and objectives of research: To establish the mechanisms of changes in the nutrient regime of typical chernozem, its agrophysical properties and crop yields in different crop rotations in relation to the dynamics of agrometeorological factors under the conditions of insufficient water supply in the eastern Forest-Steppe of Ukraine; to evaluate the productivity potential of cereals and grain crops in the system of organic farming without the use of mineral fertilizers.
 Research methods and techniques. Evaluation of the changes in agrometeorological resources of the territory was carried out using the method of mathematical and statistical analysis of the indicators of heat and moisture supply conditions: climatic water balance and precipitation. The data obtained from the stationary experiment were processed by the methods of system generalization, correlation, economic, calculation and comparative analyzes.
 Research results and main conclusions. Based on the information obtained in the course the stationary agrotechnical experiment it was established that the soil density changes over the years and depends on the hydrothermal conditions with the approximation certainity of (R2) 0.75. The inverse relationship between the specific weight of the soil and its water conductivity in terms of crop rotations with R2=0.8-0.9, by years with R2=0.6 was revealed. The variation coefficient of legumes yield was 30-33%, winter wheat – 33-37%, spring barley – 36-37%, which are the indicators of its low stability over the years. Crop yields, depending on the weather conditions of the year, also fluctuated significantly: peas between 0.8-3.2, lathyrus – 0.8-2.6, winter wheat – 0.6-6.8, buckwheat – 0.6-1.9, spring barley – 0.6-3.5 t/ha. Crop rotation with peas in terms of productivity of 2.4 t/ha of grain on average outperformed the others (2.2 and 2.0 t/ha) while maintaining the patterns of fluctuations of this indicator in relation to hydrothermal conditions.
 Having the average statistical selling price, the yield per 1 ha of crop rotation area of all studied crop rotations was almost the same with the fluctuations in the unfavorable years of 27-35 c. u./ha, in favorable ones – 97-104 c. u./ha, with the average value of 66-73 c. u./ha. If we assume that the selling price of organic products will be 25% higher than usual, the average annual yield will triple.
 Prospects for further research should correspond to the global trend of scientific research aimed at developing conceptual bases for the effects of hydrothermal conditions on agrophysical soil properties, taking into account their impact on bioproductivity of agrophytocenoses as a theoretical basis for solving the problem of increasing agricultural sustainability, in particular, using only the natural fertility of the organic-oriented model of developing the agricultural sector of the economy.

New evidence for the periodic bleaching and recovery of Porites corals during the mid-late Holocene in the northern South China Sea

Scattered evidence indicates the occurrence of coral thermal bleaching events during the mid-Holocene. However, information on such occurrences is still very rare. Ten Porites coral cores were drilled from the Wenchang fringing reef of Hainan Island, northern South China Sea. These cores contain mortality surfaces and/or growth discontinuities dating from the mid-late Holocene between 3.4 and 5.7 thousand years ago (ka, before 1950 AD). Monthly Sr/Ca, δ18O and δ13C were analyzed to reconstruct sea-surface temperature (SST), sea-surface salinity (SSS), and photosynthesis intensity during the events. Results show that the mortality surfaces and growth discontinuities of five corals are associated with high SST of 30.3 °C–33.6 °C and high SSS of 34.3–38.3. The abrupt concurrent negative shifts of 1.8‰ or more in δ13C indicate a decrease in the photosynthesis intensity, most likely attributable to the loss of zooxanthellae. These lines of evidence imply that the mortality surfaces and growth discontinuities were the consequence of coral bleaching under abnormally high temperature. The observed recovery directly after bleaching events indicates that corals in the South China Sea are capable of rehabilitation after experiencing severe environmental stresses.

Effect of Acetaminophen (APAP) on Physiological Indicators in Lactuca sativa.

This study analyzes the effects of acetaminophen (APAP) as a contaminant on physiological characteristics of lettuce plants (Lactuca sativa L.). Experiments were provided in an experimental greenhouse with semi-controlled conditions. The effect of different amounts of contaminant was evaluated by using regression analysis. Plants were grown in five concentrations of APAP: 0 µM, 5 µM, 50 µM, 500 µM, and 5 mM for 14 days in two variants, acute and chronic. The obtained results show that the monitored parameters were demonstrably influenced by the experimental variant. Plants are more sensitive to chronic contamination compared to acute. Significant (p < 0.05) deviation in photosynthesis and fluorescence was observed compared to the control in different variants. The highest doses of APAP reduced the intensity of photosynthesis by a maximum of more than 31% compared to the control. A reduction of 18% was observed for the fluorescence parameters. Pronounced correlation was described between chlorophyll fluorescence parameters and yield mainly under APAP conditions. The amount of chlorophyll was influenced by exposure to APAP.

PHOTOSYNTHETIC PRODUCTIVITY OF SINGLE-SPECIES AND COMPATIBLE CROPS OF SUGAR SORGHUM WITH SOYBEANS

The article presents the results of research to assess the impact of technological methods on the productivity of single and compatible crops of sugar sorghum with soybeans, and in particular the methods of sowing and fertilizing. The main organ of the plant that absorbs the most solar energy and has the highest intensity of photosynthesis is the leaf. The use of mineral fertilizers had a positive effect on the total leaf surface. During years of the research with the study methods of sowing and the timing for determination of total leaf surface in areas under mineral fertilizers were applied, it was greater than in areas without fertilizers. Thus, on average for 2018-2019 in the phase of ejection of panicles in areas where sugar sorghum was sown together with soybeans according to the scheme one row of sorghum + one row of soybeans under applying N120P90K120 leaf surface was 30.1 thousand m2/ha, and in areas without fertilizers - 21.0 thousand m2/ha It was found that the largest area of assimilation surface of leaves on average for two years (41.3 thousand m2 / ha) was in the phase of milk ripeness of grain under sowing two rows of sorghum + one row of soybeans and N120P90K120 consumption. For the efficient use of solar energy is important not only the size of the leaf surface area but also the duration of its active work. Photosynthetic potential is used as an indicator for characterizing of the photosynthetic work of crops during the growing season. The maximum value of the photosynthetic potential of sorghum plants on average for two years of research (2018-2019) was obtained at the end of the growing season (2.81 million m2 days/ha) in areas where it was sown together with soybeans in the method of sowing two rows of sorghum + one-row soybeans and under application of N120P90K120 doses. Keywords: Leaf surface area, photosynthetic potential, sugar sorghum, method of sowing, fertilizer.

Development and application of photoconversion fluoropolymer films for greenhouses located at high or polar latitudes

To convert and store energy in the process of photosynthesis, plants primarily use quanta of the red and blue parts of the spectrum. At high latitudes, the average daily intensity of red and blue parts of the spectrum is not very high; for many crops cultivated under greenhouse conditions, it reaches the sufficient level only on clear summer days. The problem of insufficient illumination in greenhouses is usually solved with artificial light sources. This article describes a technology for the manufacture of photoconversion fluoropolymer films for greenhouses. The fluoropolymer films described in the paper make use of original gold nanoparticles and nanoparticles with fluorescence in the blue or red region of the spectrum. In the polymer film, nanoparticles aggregate in the form of “beads”, which enhances the field of the optical wave. The film photoconverts UV and violet light into blue and red light. Gold nanoparticles also partially convert energy in the green region of the spectrum (not used by plants) into heat, which is also important for agriculture at high latitudes. In addition, impregnation of gold nanoparticles into fluoropolymer significantly increases the lifetime of the film. The films described in the paper can significantly increase the productivity of greenhouses located at high latitudes. Plants cultivated under the films have more chlorophyll and a higher intensity of photosynthesis – although their system of distance stress signals is, to a certain degree, suppressed.

Транспорт, распределение и потребление 14С -ассимилятов у сосны и ели в северотаежных фитоценозах при различном световом и азотном питании

A rational system of cuttings, mineral nutrition of plants, and preservation of softwood undergrowth during felling is one of the ways to increase the productivity of boreal forests. The physiological methods of research used in forestry and, first of all, the study of donoracceptor interactions, allow obtaining the necessary information on the efficiency level of forestry measures in the stands of pine and spruce undergrowth quickly enough (within 1–2 years) without waiting for the final result in the form of an increment in shoots. The dynam ics of accumulation, transportation and distribution of 14C in organs and tissues of a tree under the influence of selective cuttings and a nitrogen dose has been studied in spruce and pine undergrowth in stands of different species composition and age. The study objects have been: blueberry spruce and birch forests of the forest site types with varying intensity of cutting; lichen pine forests formed from pine undergrowth preserved during the cutting. It were found that, in the summer period under the canopy of spruce and birch forests, the illumination does not exceed 8–10 % of the open area and does not correspond to the biological norm for spruce. The lack of solar radiation and soil nitrogen in the undergrowth of these tree species leads to a decrease in the intensity of photosynthesis and the violation of donoracceptor bonds, delays evacuation of assimilates from a leaf and their transportation to the active zones, suppresses the growth activity and the associated with it “demand” for macronutrients sent to the leaves declines the vitality of plants. The efficiency of the root system deteriorates, the formation of a new assimilation apparatus is delayed, and the growth processes of vegetative organs are violated due to the lack production of assimilates and the disruption of their distribution system. Nitrogen introduced into the stands and selective cuttings in pine and spruce undergrowth activate the synthetic and absorption activity of the root system, improve the functioning of the assimilation apparatus, strengthen the donoracceptor interactions between the aboveground and underground organs of a tree, significantly accelerate the outflow of photosynthetic products from a leaf, and positively influence on the growth processes. It has been found that, according to the level of activity of the donor-acceptor system for the pine and spruce undergrowth, it is possible within 1–2 years to set up a system of felling and a dose of nitrogen introduced into the forest stands that most closely meet the needs of these species. For citation: Konovalov V.N., Zarubina L.V. Transport, Distribution and Consumption of Pine and Spruce 14C-Assimilates in Northern Phytocenoses under Different Illumination and Nitrogen Nutrition. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 4, pp. 77–94. DOI: 10.37482/0536-1036-2020-4-77-94

Analysis of the Mathematical Model of Photosynthesis in Protected Ground

The problem of predicting changes in the intensity of photosynthesis associated with changes in the lighting mode, atmospheric carbon dioxide concentration, and the temperature is urgent. Appropriate models can help choose the optimal mode of growing plants in protected soil, as well as serve as a basis for predicting the consequences of global climate change. It is noted that in the conditions of protected soil, the most significant factor is the illumination of plants. The aim of the research is to construct an algorithm for additional illumination of plants in protected ground conditions based on a mathematical model of photosynthesis. The authors introduced the value of the efficiency of additional illumination and studied its dependence on the coefficient of light transmission of the roof. The solution of the main task of the study is achieved by the fact that the light mode in protected ground structures is carried out on the basis of additional illumination to the ideal (optimal) for this type of plant. The entered value of the efficiency of additional illumination shows what energy costs will be for the production of photosynthesis products and, as a result, allows estimation of the economic costs. The considered method of artificial lighting of plants makes it possible to effectively use both sunlight and artificial lighting, providing an optimal lighting mode all year round, and allows to increase the intensity of photosynthesis by 50-80 %.

The influence of diesel fuel on morpho-functional state of Ulvaria obscura (Chlorophyta)

There was researched the influence of diesel fuel (DF) on morpho-functional state of Ulvaria obscura (Chlorophyta) of the Barents sea. The reaction of algae on oil products depends on concentration and duration of toxicity. Under the concentration up to 5 mg/l (100 MAC - maximum allowable concentration) there were no visible changes in cell structure during 10 days of experiment; by its end the photosynthesis of algae decreased, probably due to growth of bacterial film on the surface of thalli, preventing photosynthetic apparatus from the light. On the 7th day the number of heterotrophic bacteria increased twice, staying on this level till the end of experiment, the number of hydrocarbon oxidizing bacteria also increased. Under 1000 MAC the chloroplasts lost green colouring, the intensity of photosynthesis significally decreased, but plants maintained vitality. On the 3rd day under 2000-3000 MAC the vacuolization of cells, the destruction of cell structures occured, parallel with the cessation of photosynthesis and the death of macrophytes. The activity of antioxidant system (AAS) in experiments with DF was high, appeared by increasing of formation of hydrogen peroxide and intensity of superoxide dismutase and catalase ferments synthesis. U. obscura adaptates to concentrations of DF up to 2000 MAC.

Characteristics of Photoassimilates Transportation and Distribution to the Fruits from Leaves at Different Branch Positions in Apple

Clarifying the characteristics of photoassimilates transport and distribution to the fruits from leaves located on different branches can guide the branch composition and pruning of apple trees. A field experiment was carried out in 6-year-old ‘Fuji’3/M26/Malus hupehensis Rehd. apple trees, and the 13C-labeled tracer method was used to study the growth characteristics of the leaves on different branches (vegetative branches, long branches, mid branches, short branches, bourse branches, and cluster branches) and the translocation of 13C-photoassimilates to the fruit from these leaves at the fruit enlargement stage in 2018 and 2019. Additionally, the effect of the distance between the leaf and fruit (leaves from both short and long branches that were 20, 40, and 60 cm away from the fruit) was assessed. We found that with increased branch length, the intensity of photosynthesis and the level of photoassimilates synthesis in the leaves decreased, but increased in the leaves near the fruits. Indole-3-acetic acid, gibberellic acid, and zeatin accumulated in the leaves of the longer branches, while abscisic acid accumulated in the leaves of the shorter branches. The δ values of the 13C-labeled leaves from the short branches, the short branches 20 cm away from the fruits (S20), and the bourse branches at the fruit stage were low, and the corresponding δ values of the fruits were high. The 13C absorption of the fruit was highest in the leaves of the short branches, followed by those of the bourse branches, S20, and mid branches, and was lower in the leaves of the vegetative branches, cluster branches, and 60 cm short and long branches. The leaf 13C-photoassimilates in the short branches were more greatly transported to the fruits than those from the long branches when the distance between the leaves and fruits was the same. The 13C absorption of the fruit increased by 10.91, 5.28, and 1.14 mg at the leaf–fruit spacing of 20, 40 and 60 cm, respectively, and the leaf–fruit spacing was determined to be more important than branch type in determining the 13C absorption of the fruit.

Plant breeding for drought conditions

Plant breeding for drought conditions

Evaluation of the physiological state of feijoa (Feijoa sellowiana Berg) in subtropical Russia

The article presents the results of research examining varietal diversity with respect the activity of oxidative enzymes (EC 1.11.1.6) and the dry matter and Proline accumulation of leaves under optimal and stressful conditions. For feijoa, the most stressful period in the subtropics of Russia, with respect to hydrothermal conditions, occurs between July and September. Studies have shown that the highest degree of enzymatic activity is observed in August in the ‘Superba’ variety of feijoa, which was used as a control in this study, and the lowest level of activity was observed in the 'Sentjabrskaja' variety. The long-term water deficit experienced in September coincides with fruiting in feijoa. This causes a change in catalase activity in leaves, which is maintained until it is inhibited. Form ShV-1 of feijoa is characterised by its metabolic stability. In fact, the activity of oxidative enzymes in leaves of the variety is stable. Dry matter content per unit area increases as the leaf grows. During the drought period, which coincides with active fruiting, the leaves of the ‘Dachnaja' variety and the ShV-1 form accumulate significantly less dry matter than other varieties. In the ‘Dagomysskaja' variety, the intensity of organic matter consumption via respiration and outflow exceeds visible photosynthesis, which is expressed as a negative value (average = 1.96 g.dm-2 h). To fully characterise the physiological state of feijoa plants under the influence of abiotic factors and catalase activity in the humid subtropics of Russia, indicators of dry matter accumulation and true photosynthesis intensity can be used.

Влияние различных элементов технологии возделывания на содержание хлорофилла в растениях озимой пшеницы и ее урожайность

Abstract. The chlorophyll content is the most important factor that determines the intensity of photosynthesis and the overall biological productivity of plants. Therefore, the search for mechanisms that allow you to manage the production process is an important task, the solution of which will allow you to improve the technological methods of growing crops to obtain high yields. The purpose of the study is to determine the influence of various elements of cultivation technology on the chlorophyll content in plants and the yield of winter wheat. Methods. The objects of research were winter wheat crops of various varieties. The chlorophyll content was determined by the method of Ya. I. Milaeva and N. P. Primak. Crop accounting was performed using the combine method. Results. The relative chlorophyll content in winter wheat plants: lea predecessor on average 9,4 % higher than for cereals; the use of mineral fertilizers in a few increased this figure by 38,0 %, wheat ‒ 14,0 %; in the later sowing time the amount of green pigments in plants on average more than early and optimum of 10,5 and 4,0 %, respectively; in more thickened crops, the chlorophyll content in plants is lower than in sparse ones (by 13,0 %). The absolute chlorophyll content (g/m2) in winter wheat plants: in a few in an average of 45,0 % higher than for cereals; the use of mineral fertilizers in a few increased this figure at 73,4 %, for winter wheat ‒ 76,8 %; number of green pigments in plants at the optimum sowing time is on average higher than in the early (29,6 %) and late (15,2 %); at the optimal seeding rate accumulates more chlorophyll than the minimum (by 33,4 %) and the maximum (24,2 %). On average, for all cultivation technologies, the variety Stat' contains the largest amount of chlorophyll in plants, and Zustrich – the smallest. The yield of winter wheat for the lea precursor was 4,9 t/ha, for winter wheat – 3,3 t/ha. Use of mineral fertilizers on couple increased this indicator on average by 44,1 %, and on the cereal predecessor ‒ by 55,3 %. At the optimal time of sowing, the highest yield was formed, and on average it was 5,1 t/ha for varieties. seeding Rates did not have provable differences on the yield of winter wheat. The highest yield was obtained in the Rate variety on the predecessor of pairs on a fertilized background – 7,5 t/ha. Scientific novelty. The features of the influence of various precursors, the level of mineral nutrition, timing and seeding rates on the content of chlorophyll in plants and the yield of winter wheat crops of new varieties of selection of the North Caucasian FSAC were revealed. The correlation between the relative and absolute content of chlorophyll in winter wheat plants and its yield for these varieties in the zone of unstable moisture in the Stavropol territory was determined.

Study on New Seagrass Bed at the Coastal Area of Yellow River Estuary in Dong Ying

Seagrass resource is an important part of the Marine ecosystem, eelgrass resources worldwide recession received extensive attention of the world. Through the tracking of Yellow River Estuary in Dong Ying, we found a piece of seaweed bed, new types of seaweed for short eelgrass (Zostera japonica Asch. et Graebn), which are mainly distributed in the intertidal zone. During the investigation, seaweed cover increases by 0.54 km2 to 0.54 km2. In the year to August 2015, the biomass is 322.13 g/m2, stem branch density of 794 plants/m2. The rise and fall of seaweed bed is closely related to the water environment changes. Through the study of multiple environmental factors influence on short eelgrass life state, we found that salinity has enormous influence on the growth of eelgrass. In the five salinity conditions which the temperature is 20 °C, the net oxygen production and the activity of ribulose-1, 5-diphosphate carboxylase were the highest when the salinity was 19.459, and the photosynthesis intensity decreased when the salinity was higher or lower than this value. According to the survey, from 2002 to 2014, the inflow of the Yellow River Estuary increased from less than 5 billion cubic meters to nearly 30 billion cubic meters. Therefore, the increase of the sea water amount of the Yellow River and the decrease of the salinity in the estuarine waters are the important reasons for the growth of the seagrass bed.

Intergeneric Differences in Trophic Status of Scleractinian Corals From Weizhou Island, Northern South China Sea: Implication for Their Different Environmental Stress Tolerance

AbstractThe knowledges of trophic status (i.e., autotrophy/heterotrophy) of corals are helpful for understanding the mechanisms driving their environmental stress tolerance and bleaching resilience. We conducted this study to elucidate the differences in trophic status among corals of different genera and then explore the implication of trophic status for their different environmental stress tolerance. In this study, 117 coral samples including five genera (i.e., relatively stress‐tolerant massive genera Porites, Favites, and Favia and relatively vulnerable plating genus Pavona and branching genus Acropora) were collected from Weizhou Island, northern South China Sea. The symbiotic zooxanthellae density, δ13C of host tissues (δ13Ch), and symbiotic zooxanthellae (δ13Cz) were measured. Besides, the difference in values between δ13Ch and δ13Cz (i.e., △h‐z 13C) was analyzed. Our results indicated that both zooxanthellae density and δ13Cz values of Porites, Favites, and Favia are higher than that of Pavona and Acropora and indicate that autotrophic photosynthesis intensity of symbiotic zooxanthellae of Porites, Favites, and Favia is higher than that of Pavona and Acropora. Besides, both δ13Ch and △h‐z 13C of Porites, Favites, and Favia are lower than that of Pavona and Acropora and indicate a higher contribution of heterotrophic predation to the coral host of Porites, Favites, and Favia. These comparisons suggest that trophic status of relatively stress‐tolerant Porites, Favites, and Favia is more plasticity than vulnerable Pavona and Acropora, which is conducive to maintain a positive energy budget. This is one of important factors leading to different environmental stress tolerance and bleaching resilience among corals of different genera.

Структурно-функціональний стан листків колоноподібних сортів яблуні в умовах Київщини

Структурно-функціональний стан листків колоноподібних сортів яблуні в умовах Київщини

Comparison of the Ecophysiological Parameters of Pine and Spruce in the Serebryanoborsky Experimental Forest District

Research conducted in Serebryanoborsky forestry Institute of Forestry RAS. To evaluate gas exchange, an original setup based on an infrared gas analyzer was used. The installation created at the Forestry Institute of the Russian Academy of Sciences made it possible to simultaneously, round-the-clock receive daily changes in the intensity of photosynthesis and respiration of adult trunks of pine and spruce trees. It was found that the respiration of pine and spruce trunks, calculated on the surface of trunks, does not differ significantly, while the intensity of photosynthesis of spruce (when calculated on the surface area of needles) is almost two times lower than that of pine. However, we believe that when calculating the area of growth, the differences will be insignificant, since the mass of spruce needles in the stand is much greater than the mass of pine needles per unit area of growth. It was found that the intensity of photosynthesis of spruce is more affected by moisture deficiency. So, during the day, with a PVPL equal to -0.8 MPa, on a cloudy day from 9 oclock it reduces the intensity of photosynthesis, whereas in pine only after 12 hours. On cloudy days, spruce with the same water supply practically does not decrease the intensity of photosynthesis during the whole day, and differences in the light curves of photosynthesis of pine and spruce are less significant. The calculation of pine and spruce trunk respiration per day depends on the arrival of solar radiation on cloudy days, the respiration rate is two times weaker than on low-cloud days. Thus, environmental and physiological indicators reflect the state of stands. The most informative indicator is the predawn water potential of the leaf (needles). This indicator characterizes the water availability of the tree, regardless of the reason for the decrease in water availability. The daily course of photosynthesis intensity and CO2 emission from the surface of the trunks are also informative indicators of the state of trees. However, when comparing different breeds by shade tolerance, it is better to use breathing from the surface of the trunks. Приведены результаты оценки влияния окружающей среды на эколого-физиологические показатели ели обыкновенной и сосны обыкновенной. Установлено, что дыхание стволов сосны и ели при расчете за сутки зависит от поступления солнечной радиации: в пасмурные дни интенсивность дыхания в 2 раза слабее, чем в малооблачные. При недостатке влаги интенсивность фотосинтеза ели снижается в большей степени, чем у сосны.

Приложение статистических методов к показателям фотосинтеза тритикале при хлоридном стрессе

The paper presents the results of a study of the relationship between photosynthesis indicators of triticale shoots under conditions of short-term NaCl stress. For this, the principal component analysis (PCA) and cluster analysis were used. It was established that the characteristics of photosynthesis form three groups: (1) carbonic anhydrase and electron transport, (2) chlorophyll and carotenoids, (3) photosynthesis intensity. The correlation coefficients between the indicators are 0.85 and 0.97 for the first two groups, respectively. Using the cluster analysis method has led to similar results. Further analysis of the data with PCA for the characteristics of photosynthesis and oxidative stress showed that the indicators can also be combined into three groups: (1) stomatal conductivity, chlorine and sodium, (2) chlorophyll and carotenoids, (3) photosynthesis intensity and Rubisko activity. For physiological and biochemical parameters, the highest correlation coefficients were as follows: electron transport – lipid peroxidation (0.98), chlorophyll – carotenoids (0.97), carbonic anhydrase – LPO (0.86), carbonic anhydrase – electron transport (0.85), electron transport – hydrogen peroxide (0.63), LPO – hydrogen peroxide (0.62). The cluster analysis method suggests a close relationship between electron transport and the accumulation of hydrogen peroxide, carbonic anhydrase and lipid peroxidation. Based on the results obtained, conclusions are drawn about the close relationship between the activity of carbonic anhydrase and electron transport, and the magnitude of lipid peroxidation under experimental conditions, which, however, requires direct experimental evidence of such connections.

Leaves anatomical and physiological adaptations of Vinca major ‘Variegata’ and Hedera helix L. to specific roof garden conditions

Urban agglomerations create extreme microclimates for plants, in which growth, development and survival means adaptation. Plantations expansions beyond the typical gardens to buildings, walls or other build structures were realized in many cities with a rigorous selection of plant species. Although the number of woody species well adapted to the urban environmental conditions is quite large, few species manage to grow and develop on the roofs. Two species - Vinca major ‘Variegata’ and Hedera helix, regularly used for this type of plantations in Bucharest, were selected to understand their mechanism of adaptation. A comparative study was conducted on these species, growing on a rooftop garden and at the ground level into a typical garden. Both species revealed considerable anatomical differences of the leaves. In addition, physiological determinations revealed a stronger intensity of photosynthesis, an intense transpiration and a lower respiration rate at plants grown in the roof garden.

Влияние совместного внесения минеральных и органических удобрений на развитие и урожайность кукурузы

The role of macro– and micronutrients for corn plants is great. They increase the intensity of photosynthesis, participate in biological processes. The work is devoted to the development of science–based methods for increasing the yield and quality of corn. Field experiments were conducted in the northwestern zone of Azerbaijan. Test sites were laid in 4-fold repetition, in 6 versions. Used: ammonium nitrate, simple superphosphate, potassium sulfate, manure, compost of various waste products. All agricultural activities were carried out according to the developed technology. Before ploughing, the entire rate of manure, phosphorus and potassium was introduced, in early spring before tillage. As a result, it was revealed that with the introduction of 20 t/ha of compost — the yield of corn was 85.1 c/ha, i.e. an increase of 15.9 c/ha. It can be concluded that mineral fertilizers in combination with manure in the proportions chosen by the authors effectively affect not only the growth and development of plants, corn productivity also increases.