Metamorphosis differences of caudiciform plants as an adaptation to arid conditions

In the course of evolution, the formation of succulent variations in the underground and surface parts of plants in different taxa could occur simultaneously under the influence of similar abiotic factors, in particular as an adaptation to arid conditions, and similar structural features even in distant families are a manifestation of convergent evolution. Along with this, the development of such adaptive structures in ontogeny can occur in different ways in different taxa. Studying the anatomical and morphological features of the vegetative organs of Fockea edulis (Asclepiadoideae, Apocynaceae) at the early stages of ontogenesis and comparing them with those of other plants will improve the understanding of the features of growth and development of caudex-like plants. The research was conducted on seedlings, juvenile and immature plants of F. edulis. When comparing the features of the development of vegetative parts of three representatives of the Apocynaceae family, we found that the strategy of succulent traits development in F. edulis at the organ level is characterized by the active development of the hypocotyl already at the seedling stage, similar to Adenium obesum, and the subsequent formation of an expanded basal part of the stem due to the combined cortex-pith thickening and radish-like root due to the growth of xylem parenchyma. However, Petopentia natalensis is characterized by a mesophytic seedling. It was established that secondary thickening in the basal part of the stem occurs in two individual ways: in Adenium obesum, the cambium generates solid rings of phloem and parenchymatized xylem; in P. natalensis and F. edulis, the bundle type of conducting elements is preserved. The thickening of the tap root in F. edulis is similar to that in A. obesum

Various antioxidant responses to hyperthermia in anatomically different species of the genus Rosa

The heat and drought resistance of plants depend on their anatomical and biochemical features. In the present study, the adaptive features of three species of wild rose (Rosaceae, Rosales) under the short-term impact of high-temperature stress have been characterized. Plants of the species Rosa donetzica Dubovik, R. reversa Waldst. et Kit. and R. spinosissima L. were exposed to a temperature of 40 degrees C for 3 hours, following which peroxidase and superoxide dismutase activity, photosynthetic pigments and flavonoids’ content, and lipid peroxide oxidation level in the leaf were determined. In our investigation, the anatomical structure of leaves and drought resistance of three species of Rosa were studied. Xeromorphic features are the most expressed for R. reversa and R. spinosissima and almost absent for R. donetzica. It has been established that R. spinosissima is photophilous whereas R. donetzica is shade-tolerant. The relatively lower development of epidermic tissue in R. donetzica could probably contribute to more active destruction of the pigment complex under high temperature stress. The obtained data about changes in activity of peroxidase, superoxide dismutase, content of photosynthetic pigments and flavonoids, and level of lipid peroxidation indicate the low heat resistance of R. donetzica in comparison with the other two species. R. reversa, R. spinosissima were more tolerant to short-term hyperthermia. They showed faster antioxidant response, mainly due to the induction of peroxidase activity under stress. The species with the most expressed xerophytic features of anatomical structures have rapid antioxidant response and are more resistant to short-term hyperthermia. The induction of some activity of antioxidant enzymes "in reserve" is a less effective form of adaptation in wild roses. Such activation of enzymes is observed in plants with a more mesophytic structure. Flavonoids and superoxide dismutase were thermolabile to short-term influence of high temperature; therefore they play an insignificant role as antioxidants in the protecton against oxidative stress caused by high temperature stress in wild roses

Species-specific response to acute hyperthermal stress of Haworthia (Asphodelaceae) plants

An increase in environmental temperature is one of the most common stress factors for plant organisms. The study of the plants’ adaptation to stress factors remains extremely important and relevant. This article presents the results of a acute short-term influence of hyperthermia on species of two subgenera of the genus Haworthia Duval. We investigated the different levels of antioxidant protection and damage degree of the members of two subgenera of the genus Haworthia at the biochemical level, measuring the lipid peroxidation, superoxide dismutase and peroxidase activities, total flavonoid content and content of photosynthetic pigments with a spectrophotometer. To determine the drought tolerance of plants, the water supply of tissues, water shortage and loss of water after an hour of wilting were measured. The values for different groups were compared by ANOVA followed by the Tukey multiple comparison test. The studied plants were warmed in a thermostat at temperatures of 40 °C and 50 °C for three hours under the conditions of natural light. The control group of plants was kept at 25 °C. The research has shown that H. attenuata, H. limifolia and H. cymbiformis are characterized with the increase of concentration of malonic dialdehyde at 40 °C and 50 °C, but a significant difference of values wasn’t received,which indicates the relative resistance of these plants to the influence of high temperatures. The sharp increase of temperature causes the highest level of lipid peroxidation in H. parksiana plants, along with which, warming to 50 °C launches a mechanism of activation and synthesis of superoxide dismutase and flavonoids for the plants. The studied species of the subgenus Haworthia have a photosynthetic system relatively resistant to thermal stress in comparison to the subgenus Hexangulares. H. limifolia plants have a slight inhibition of photosynthesis. The adaptation of H. cymbiformis to thermal stress is due to the strategy of accumulation of a pool of active enzymes, superoxide dismutase, peroxidase, flavonoids under normal conditions and the activation of new peroxidase enzymes as a result of stress. H. attenuata is characterized by activation of new enzymes of superoxide dismutase and peroxidase under stress. It was found that H. cymbiformis and H. attenuata are more heat resistant in comparison with the other two species. Acute short-term hyperthermia has a different influence on the antioxidant system of different species of Haworthia. H. limifolia has the highest drought tolerance, H. cymbiformis has the lowest, the other two species from different subgenera have similar drought tolerance indicators. We did not find any dependence of the mechanisms of action of the antioxidant system under hyperthermia on the type of adaptation to arid conditions at the anatomical level in plants of different subgenera of the genus Haworthia

Ідентифікація статі рослин актинідії гострої (Actinidia arguta (Siebold & Zucc.) Planch. ex Miq.)

The problem of gender differentiation and the methods and criteria search for its diagnosis in dioecious plants of the Actinidia at an early stage of development is an extremely important item. It is important both for gardening practice and for successful breeding work with this culture. The morpho-anatomical studies of Actinidia arguta one-year male and female plants twigs were performed using NY-1 light-optical microscope. The qualitative content of starch was studied in one-year twigs of plants using of an iodine solution. The study of the starch content dynamics in the one-year twigs of male and female plants has revealed a variation of the content indicators that depends on the plant development phase and the weather conditions. The two peaks of its accumulation during the year have been defined (the first one is in October, after defoliation, and the second one – is in the spring at the beginning of the twigs growth). The difference in the indices between male and female plants was represented mostly during the second maximum (the length of young twigs reached 15–20 cm). The method for the Actinidia Lindl. seedlings gender determining with the use of qualitative reaction on starch (iodine solution) on the basis of the long-term researches conducted on the male and female Actinidia Lindl. plants, the successful testing on the seed origin Actinidia Lindl. plants was proposed. The difference in colour is observed in 3 minutes after the reagent application. The colour is localized in the perimedullary zone in male individuals, while in female individuals it extends through the parenchyma of the xylem rays to the external layers. The advantage of this method is the simplicity and the portability of the implementation, the availability to the general public of the gardeners and the possibility of mass use without causing any harm to the plants. The application of this method will contribute to the improvement of the breeding work and the use of pollinating plants of Actinidia Lindl. of the seed origin at planting and significantly reduce the raising cost for the selection material.Актинідія – це дводомна культура, і для забезпечення високої продуктивності її насаджень на ділянках необхідно одночасно висаджувати чоловічі та жіночі рослини у співвідношенні 1 до 5–7. Сортові жіночі рослини для насаджень одержують лише способом вегетативного розмноження, тоді як чоловічі рослини-запилювачі можуть бути як вегетативного, так і насіннєвого походження. Численні дослідження свідчать, що саме сіянці краще пристосовуються до нових умов зростання, вирізняються вищою адаптивною здатністю, підвищеною стійкістю до негативних чинників навколишнього середовища порівняно з вегетативно розмноженими рослинами. За літературними даними, вихід рослин-запилювачів інколи сягає 90 %, а то й 100 % від загальної маси сіянців. Ефективні методи визначення статі сіянців актинідії до вступу їх у генеративну фазу розвитку (на 5–7-й рік після посіву) нині відсутні, тому питання пошуку критеріїв ранньої діагностики статі рослин актинідії й опрацювання методу її визначення є надзвичайно актуальним і має важливе теоретичне та практичне значення. На основі комплексного вивчення особливостей чоловічих і жіночих рослин Аctinidia arguta (Siebold & Zucc.) Planch. ex Miq. колекції Національного ботанічного саду ім. М. М. Гришка НАН України запропоновано метод діагностики статі сіянців у прегенеративний період їх розвитку. В основу методу ідентифікації статі A.arguta, що пропонують, покладено оброблення рослинних зразків хімічним реагентом, подальший аналіз результатів реакції та встановлення статі рослини за забарвленням зразків. Точність визначення сягає 95 %, що вказує на високу ефективність і перспективність частого використання запропонованого експрес-методу визначення статі у прегенеративному періоді розвитку рослин. Застосування цього методу дає змогу визначити стать рослин уже в 2–3-річному віці

The influence of light regime on the growth data and pigment composition of the plant Gentiana lutea cultured in vitro

New technologies of reintroduction of plant species presuppose implementing both traditional and biotechnological methods for obtaining certain planting materials. However, plants cultivated in vitro exist in specific conditions that lead to changes in their structural and functional state. This explains why it is hard for them to adapt to ex vitro and in situ conditions. Therefore, there is a need for the development of a multistage method of cultivating in vitro plants that would make the influence on their adaptive mechanism in ex vitro and in situ conditions possible. One of its stages is the optimization of the light regime of cultivation which can both initiate the change of the state of the photosynthetic apparatus of plants and increase their bioproductivity stimulating the work of their protective system. This work studies changes in the morphogenesis, growth data and pigment composition of the rare species of Gentiana lutea L. of three populations in the Ukrainian Carpathian (mountains Pozhyzhevska and Sheshul-Pavlyk, plateau Lemska) in vitro focusing particularly on the cultivation light regime. The research has proved the inefficiency of using fluorescent lamps of daylight lamps (LD) type as source of illumination because the low intensity of luminous flux in the area of photosynthetically active radiation (PAR), as well as high proportion of wavelength of blue (400–500 nm) and green (500–600 nm) range in the spectrum cause specific reactions of photomorphogenesis, which, despite the high content of pigments in plastids, lead to poor development of root systems, stretching the stems, formation of small leaves with thin leaflet plate, generally low productivity and low adaptive potential of G. lutea plants to ex vitro and in situ conditions. Complement of cold white light lamps to the fluorescent lamps LD type in the ratio of 1 : 1 enables one to increase the intensity of illumination in the field of PAR and raise the fraction of wavelength of red range (600–700 nm). Such light conditions both improve the bio-productivity of G. lutea plants of all three populations cultured in vitro in comparison to the LD type regimen, reducing the content of chlorophyll b and carotenoids in light-harvesting complexes of photosystems and facilitate an increase in the microclonal multiplication factor without using higher concentrations of exogenous growth regulators,which significantly reduces the cost of the process of obtaining planting materials. It was proved that a combination of LD type lamps, cold white light lamps and phytolamps in the ratio 1 : 1 : 0.6 should be used on the final stages of preparation of the planting material of G. lutea before transferring it to ex vitro and in situ conditions. This relates to the fact that the increase of the wavelength of the red range results in the widening of the active surface of the leaves, rise in the content of photosynthetic pigments, and the noticeable growth of the aboveground and underground parts of the plants. The article assumes that the use of such illumination mode will ensure a faster transition of cultured in vitro G. lutea plants from heterotrophic to autotrophic nutrition, improving their adaptive potential and enabling easier adaptation to non-sterile ex vitro and in situ conditions

Heat- and drought-resistance of some representatives of the genus Rhododendron L.

Data about changing the content of photosynthetic pigments in leaves of plants Rhododendron makinoi, R. degronianum, R. сallimorphum and R. brachycarpum after exposure to high temperatures are presented. Established degree of drought resistance of these plants. The most drought- and heat-resistant species are plants of Japanese origin

Preservation of features of anatomical polymorphism of Deschampsia antarctica É. Desv. (Poaceae) during in vitro clonal reproduction

We studied the anatomical features of the leaf structure of Deschampsia antarctica É. Desv. (Poaceae) obtained from seeds collected from different habitats of the maritime Antarctic. ese plants have been maintained in culture in vitro for more than 7 years. e plants include stable chromosome forms comprising diploids (2n = 26), a diploid plant with B-chromosomes (2n = 26 + 0–3B), a triploid with rearranged chromosome morphology, and myxoploids with different ratios of diploid and nondiploid cells in the root meristem. e D. antarctica plants that were studied generally had a similar anatomical structure in culture in vitro and in nature. At the same time, plants of different cultivated genotypes also displayed their own leaf structure features. In particular, qualitative features included asymmetric four-ribs and five-rib leaves instead of typical three-rib leaves for some genotypes, some individuals characterized by the presence of unicellular nonglandular pointed trichomes on an adaxial side, differences in vascular bundle sheath, and other features. No clear dependence of the anatomical structural features on the chromosomal status of the studied genotypes was evident. At the same time, differences were evident in traits that included the number of stomata, thickness of the outer cell walls of the epidermis, bundles sheath state, number of leaf ribs, and the persistent presence of trichomes under prolonged in vitro cloning. e findings indicate that D. antarctica plants collected from different locations of the maritime Antarctic for long-term cultivation in vitro under standard cultivation conditions retain the anatomical characteristics of the wild plants. e polymorphism of in vitro-cultivated plants is not related to the polymorphism of their karyotype, but is apparently due to the heterogeneity of the original plants and possibly the epigenetic fixation of a number of anatomical features produced in the natural microhabitats of D. antarctica populations