The paper presents the results on resistance of Aesculus hippocastanum Linnaeus, 1753 trees to Cameraria ohridella Deschka & Dimić, 1986 (Lepidoptera, Gracillariidae) impact under conditions of a modern urban environment on the example of Dnipro city as the largest industrial city in Ukraine. Field experiments were conducted in all park areas of the city, which allowed covering the full gradient of the existing urban environment and considered the different degrees of the tree settlement by the invasive insect species. The research of the impact of C.ohridella caterpillars’ vital activity on the photosynthetic apparatus state was carried out by applying a chlorophyll fluorescence induction technique. Diagnosis of photosynthetic dysfunction of fresh Ae.hippocastanum leaves was conducted using a portable “Floratest” fluorometer manufactured in Ukraine. Interpretation of the obtained Kautsky curves showed that significant changes in their critical parameters associated with the degree of leaf damage by C.ohridella caterpillars were not detected. The influence of tree growth site conditions on the following 4 main indicators of chlorophyll fluorescence induction was established: the initial value of fluorescence induction after irradiation; the value of “plateau” fluorescence induction; the maximum value of fluorescence induction; the stationary value of fluorescence induction after light adaptation of the plant leaf. It was found that the efficiency coefficients of photochemical processes in Ae. hippocastanum trees growing in low terrain levels differed significantly, which can probably be interpreted as their response to the specific characteristics of the urban environment.
25 December 2022 in Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Purpose. Determination of the relationships between the concentrations of Zn, Cu, Pb, Cd in the atmospheric air and in the assimilative organs of the false acacia (Robinia pseudoacacia) trees the most common species in the system of landscaping of industrial cities. The objectives of the study included finding out the peculiarities of the spatial distribution of metal pollutants in green spaces of Robinia pseudoacacia in Dnipro city. Methodology. The study was conducted in the system of green spaces of the industrial city of Dnipro, in the atmospheric air of which pollutants dominate, whose source is emissions from metallurgy, energy and motor transport. To carry out the experiment, the method of atomic absorption spectrophotometry was used to determine the concentrations of heavy metals. The trend of technogenic emissions into the atmosphere was estimated by statistical methods. The spatial distribution of accumulation of essential and toxic metals in the Robinia plantations of the industrial city was built on the basis of the obtained experimental data. Findings. Among the studied pollutants, the maximum concentration in the assimilation organs was found for Zn, whose range was 1530 mgkg-1. Almost the same level of accumulation was reached for Cu and for Pb: 3.917.2 and 8.610.8 mgkg-1, respectively. The presence of Cd, which is not an essential element, has been established, which allows considering Robinia plantations as a potential depositor of Cu and Cd in conditions of polyelemental pollution of industrial cities. Originality. It was established that Robinia plantations as an element of the green infrastructure of industrial cities are characterized by the maximum effect of Cu (among other heavy metals) translocation and are effective potential depositors of Pb when its normative values in the atmospheric air are exceeded.. Practical value. On the basis of the obtained experimental data, the spatial distribution of accumulation of metals as pollutants in Robinia plantations was constructed, which can be considered in the plane of optimization of the state of atmospheric air in the city. The cartographic materials that can be used by the subjects of environmental monitoring and green construction of industrial cities were obtained.
This article proposes a completely new method of resolving the pressing global environmental problem of assessing the capacity of invasive organisms to adapt to new environmental conditions. A new three-step approach to the evaluation of vital and ecological functions of invasive species is recommended. In addition to classic species and population surveys, it was proposed to apply a stress-resistance biochemical assessment of invasive species. Stress resistance can be regarded as the main response of living organisms to changes in continuous environmental components. The obtained results will provide an opportunity to give a qualitative prognisis of what adaptive capacity an invasive species has,what precise ecological functions and for what time period it can perform in a new ecosystem.
In the last two decades, the horse chestnut (Aesculus hippocastanum L.), introduced into the steppe zone of Ukraine, has been severely affected by the horse chestnut leaf miner Camereraria ohridella Deschka & Dimič, 1986, which results in damage to the assimilating organs, premature leaf defoliation and, as a consequence, a significant reduction in the reserve substances required for normal life of the plant. In recent studies, the main focus has been placed on the study of the pest’s effects on the non-enzymatic antioxidant protection system of the representatives of the genus Aesculus, while the enzymatic system of horse chestnut protection from the active forms of oxygen under stress is still poorly understood. The purpose of this study was to evaluate the reaction of catalase and two peroxidases of A. hippocastanum leaves, which differ in the level of damage by C. ohridella. The intensity of damage to A. hippocastanum leaves by the horse chestnut leaf miner in the park zones and botanical gardens of Dnipro city was determined, the activity and isoenzyme composition of benzidine-peroxidase, activity of guaiacol-peroxidase and catalase were measured. The lowest average benzidine-peroxidase activity was found in the group of trees with low level of leaf blight and the highest activity – in the group with high level. The opposite dependence was shown by catalase, the activity of which significantly decreases with increasing level of damage inflicted by the phytophage on the chestnut’s assimilating organs. Based on the determination of the variation coefficients, it has been shown that benzidine-peroxidase activity has a higher level of variability than that of catalase and guaiacol-peroxidase. It is established that under the influence of the leaf miner, activity of guaiacol-peroxidase was significantly higher by 87.1% and 75.6%, respectively, for medium and high levels of damage caused to the leaf by this phytophage as compared to that for low levels of damage. The increased level of leaf damage caused by the phytophage is reflected in the change in the isozyme profile of benzidine-peroxidase. The high activity of benzidine-peroxidase in the leaves of A. hippocastanum is due to the presence of several molecular forms that exhibit maximum activity in the narrow pH range (4.15–4.69). Quantitative redistribution of activity between the different molecular forms of benzidine peroxidase can be considered as the main regularity of changes in the expression of benzidine-peroxidase caused by different levels of leaf damage. The results showed that only one benzidine-peroxidase isoform with an isoelectric point of 4.15 shows a significant increase in activity (on average by 2.1 times) in A. hippocastanum leaves with medium and high levels of damage by C. ohridella. Significant reduction in activity is reported for dominant isoperoxidase with an isoelectric point of 4.25 revealing medium pest damage, and for high damage only a decreasing tendency is shown. The data obtained show that horse chestnut trees can specifically respond to mechanical damage by C. ohridella to leaves due to the changes in the activity of individual molecular forms of peroxidase. Further studies of oxidative metabolism are needed to understand the formation of resistance of representatives of the Aesculus genus to damage caused by this moth species based on a wider range of redox enzymes.
Antioxidant enzymatic activity and soluble protein content in Robinia pseudoacacia L. (black locust), invasive tree in Europe, plants were determined under feeding conditions of the caterpillars of Parectopa robiniella Clemens, 1863, invasive miner in Europe, in trees of three (I, II, III) age groups (5–10, 15–25, and 40 years). Biochemical analysis data showed significant differences between reference and experimental leaf samples in different urban ecosystems. There was no association between changes in catalase and peroxidase activity and protein content under the influence of leaf blotch miners depending on the tree age. Significant variability of proteins under P. robiniella influence was noted; the highest of its values were recorded in the leaves of ІІІ-aged trees. In most plantings (and especially in trees of age group III), an increase (1.2 to 2.7 times) in GPx activity or the absence of its changes was registered both in the ecologically favorable zone and in the locations affected by emissions from road transport and industrial enterprises. Plants of age groups I and II in the emission areas of metallurgical, pipe-rolling, and chemical industries experienced a significant decrease in GPx activity (by 20.2–44.6%) in the leaves damaged by the phytophage. In most of the plantings studied, catalase showed an increase/stability of its activity in all age groups of trees under condition of pest attack. The highest increase in САТ activity (2.1 times) was recorded in young R. pseudoacacia plants in an ecologically favorable area of the city.