THE INFLUENCE OF RECREATIONAL IMPACT IN FOREST COMMUNITIES ON THE ALLELOPATHIC REGIME OF TREE EDIFICATORS

The allelopathic regime of the phytogenic field of model middle-aged trees of seven forest formations in the zone of humid subtropics of the Sochi Black Sea region was evaluated with an admissible range of stages of recreational digression. The method of biotesting of water extracts from forest litter, soil and roots was used to determine the spatial gradient of allelopathic activity of the phytogenic field environ-ment. The share of participation of the allelopathic factor in the formation of the phytogenic field at certain stages of recreational digression was established. It was determined that the value of allelopathic intensity of the phytogenic field, depending on the stage of recreational digression, field zones and edifi-cator species, can characterize the degree of resistance to the introduction of new species, recreational resistance and community stability.

Significance of the cronobiological factors in a spa treatment of gynaecological patients

In the article the outcomes of the research of efficiency of complex SPA treatment of the patients with chronic inflammatory diseases of organs of the small pelvis in various seasons of the year in conditions of humid subtropics are indicated. The dynamics ofa psycho-emotional condition, vegetative reactivity, condition of the protective-adapting mechanisms of the gomeostasis are investigated, depending on a kind of applied SPA treatment (hydrogen sulfide or iodine bromide)? In cool and warm periods of a year. The recommendations for differentiated rehabilitation treatment of patients with valiants of clinical process of chronic inflammatory diseases of organs of the small pelvis and complications, accompanying them, in conditions of humid subtropics are represented.

Changes in the physiological state of peach plants influenced by drought

The article presents experimental data on physiological and biochemical studies of stone fruit culture on the example of Persica vulgaris (Mill.) In the humid subtropics of Russia. The research has been carried out since 2011 in the Laboratory of plant physiology and biochemistry of the Subtropical Scientific Center of the Russian Academy of Sciences on peach varieties of different ripening periods grown in the humid subtropics of Russia. To identify any physiological changes in the body of peach plants during drought, especially in summer, comprehensive diagnostic studies of the water regime (leaf turgidity, determination of the thickness of the leaf blade, water deficiency) and pigment composition are carried out, characterizing the functional state of peach plants. Under unfavorable conditions, promising varieties have a higher ratio of chlorophylls to carotenoids, which confirms their more developed adaptive potential. Studies of this nature have been carried out in order to identify and select resistant peach plants among the studied varieties, which would correspond to the humid region of the Black Sea coast of the Krasnodar Territory. In the subtropical zone of our region, the issue of drought resistance has always been acute, since the impact of negative environmental factors (cool spring, accompanied by drizzling rains and a long summer shortage of air and soil moisture) on peach plants lead to a decrease in productivity and a deterioration in the quality of fruits, which makes their unsuitable and non-transportable. It has been found that among the tested plants, peach varieties Maycrest, Fayet, Larisa have been distinguished by high physiological indicators, such as: low water deficiency – 12,20–14,65%, leaf turgidity ­– 0,18 mm, saturation of leaf tissues within 70,12–79,21%, the content of carotenoids is 0,5–0,7 units, which is a confirming sign of their high resistance to the negative effects of weather conditions in the south of Russia.

New varieties and promising hybrids of Pelargonium grandiflorum hybridium hort. in humid subtropics of Russia

A genetic collection of the genus Pelargonium L’Herit. ex Ait., with 40 % stock represented by Pelargoniumgrandiflorum hybridium hort., is originated at the Federal Subtropical Research Centre of the Russian Academy of Sciences. The main collection varieties, including Aristo, Elegance, Candy Flowers, Hazel and Bermuda, are foreign selections attaining their best qualities under optimal soil and climatic conditions. Cultivation in humid subtropics disturbs their growth and development, at the same time as deteriorating their productivity and ornamental value. The research aimed to study the hybrid stock towards the selection of hardiest, most ornamental and long-flowering forms corresponding to a specified variety model. The variety model developed for Russian subtropic agroclimate incorporated a main set of economically valuable and adaptively significant traits. Over 30 varietal crossbreedings have been conducted to select for promising recombinants and hybrid families. A high variability of phenotypic ornamental traits has been observed in the crosses offspring. We identified 15 promising hybrids from the total morphological trait combination. Adaptive selection against stress factors has been proved effective. The most successful combinations were Hazel Ripple x Yashma, Hazel Cherry x Rozovyy Briz and A. Darling x Rozovyy Briz. A subset of elite forms (Kd-15-43, Kr-16-28 and Kc-18-22) maximising the number of significant breeding traits have further been selected towards a higher total score (≥95). K.j.-17-15, Kq-18-04 and K.ya-16-03 were recognised promising for large-flowered form selection. The Yagodnyy Tsvet variety, Kv-18-01 and K.d.-18-09 hybrids (over 35 inflorescences) have been identified as sources for high flower production. K.p-17-65, Kr-16-28 and Kc-18-22 were the hybrids with flowering period exceeding 100 days. All crosses were based on Hazel as a maternal form sourcing the trait.

Microbiological Indicators of Meadow-Brown Soils of Natural Cenoses

The article presents data on microbiological indicators of meadow-brown soils of semi-humid subtropics of the Lenkoran region. Meadow-brown soils are typical representatives of a number of hydromorphic soils of Azerbaijan. These soils are formed under sparse forests and shrub plantations with well-developed herbage. The soil-forming rocks are deluvial-proluvial deposits of clay composition. The influence of groundwater and surface runoff on soil formation is periodic. In the described soils, biological processes, including the activity of microorganisms, take place at moderate moisture level (10–25%) and temperature (18–23 °C). The paper presents a comparative analysis of the total number of microorganisms (in a layer of 0–50 cm) between typical meadow-brown, meadow-brown leached, meadow-gray-brown and gray-earth-meadow soils. We have shown changes in the total amount of microbiota for individual horizons of meadow-brown soils. Changes in the quantitative indicators of the microbiota of the studied soils also affect their overall biogenicity. A close relationship has been established between humus and the number of microorganisms. As the humus decreases in individual horizons, an adequate decrease in the number of microbiota is noted. If in 0–5 cm, 5–10 cm, 10–15 cm layers the amount of microbiota varied between 6,13–5,83–4,81 million per gram of soil, then in deeper layers of 15–20 cm, 20–25 cm, 30–40 cm, 35–50 cm, their number gradually decreases to 3,9–3,10–2,65–1,81–1,52 million per gram of soil.

Organic antioxidant dynamics in Hydrangea macrophylla Ser. leaves in humid subtropics of Russia

Subtropical ornamental crops have been cultivated and studied in the humid subtropics of Russia for over a century. Nevertheless, a comprehensive evidence on their adaptation and stress is rather scarce for the region. The climatic conditions in Russian humid subtropics may occur extreme to introduced plants, which warrants research into their adaptive reactions to soil aridity and summer temperatures over +30 C°. Given the situation, understanding the mechanisms of main stressor-adaptive responses is relevant in ornamental crops, including Hydrangea macrophylla Ser. Gas chromatography-mass spectrometry was employed to study ethanol leaf extracts in various-hardiness Hydrangea macrophylla Ser. cultivars, relatively hardy (Draps Wonder, Admiration, Altona), medium-hardy (Souer Theresa) and susceptible (Harlequin, Madame Faustin) forms. Eleven endogenous organic compounds have been identified, of most interest being antioxidants and stress-protectants, including diarylethylene aromatic hydrocarbons (2,4’-dihydroxystilbene), squalene and phytosterines (y/p-sitosterol). The organic leaf content changed in response to hydrothermal stress in H. macrophylla, with a maximal concentration (2,4’-dihydroxystilbene 14.0, sitosterol 5.7 %) observed in favourable hydrothermal conditions of April, and minimal — in the first August decade (8.5 and 1.7 %, respectively). Meanwhile, the relatively hardy Draps Wonder, Admiration and Altona varieties possessed the highest organic content of 2,4’-dihydroxystilbene (18.4, 21.5, 21.6 %) and y/p-sitosterol (5.7, 7.5, 6.0 %) both in optimal and stressing times. The lowest synthesis in the periods was observed in the unstable H. macrophylla varieties, Madame Faustin (6.9 and 1.1 %) and Harlequin (7.6 and 1.4 %).

Bioresource potential of chaenomeles (Chaenomeles L.) in the humid subtropics of Russia

The taxonomic composition of the genus Chaenomeles L. was determined in the conditions of the Sochi Black sea region. Morphological and biological description was made and fruiting was evaluated for 19 taxa. Decorative cultivars Ch. japonica, Ch. speciosa, Ch. × superba, Ch. × vilmoriniana are of interest for cultivation in the humid subtropical zone of Russia. Fruit cultivars are not represented. Ch. sinensis is recommended as a fruit crop of Chaenomeles and a promising form of Ch. × superba has been identified. The cultivar Ch. speciosa ‘ Kermesina ' is universal and recommended for use in both gardening and fruit growing.