The need for the vernalization duration of soft winter wheat collection samples

The need for vernalization is a duration-dependent effect of low, positive temperatures in order to ensure the plants' transition to generative development. If the requirement for the duration of germination is not met, the plant will not enter the stage of forming generative organs. The vernalization requirements of winter soft wheat samples of different geographical origins are determined. An assessment of the vernalization period duration influence on the severity of the elements of the yield structure is given. The research material consisted of 15 cultivars of soft winter wheat of various geographic origin. The samples were germinated in paper rolls, then vernalized in a climatic chamber at a temperature of 3–5 ºС for 60, 50, and 40 days. At the end of vernalization, 10 plants of each sample were planted in a greenhouse. The dates of the onset of phenological phases were noted: tube emergence, earing, flowering. To determine the main elements of the yield structure, a structural analysis of plants was carried out. With an increase in the vernalization period, a decrease in the interfacial periods from tube emergence to flowering was noted. The influence of the timing of vernalization was noted on the manifestation of the spike length trait. It was found that the total number of stems and the number of productive stems in almost all varieties decreases with an increase in the period of vernalization. Significant differences between collection varieties in the need for vernalization, due to both their geographical origin and the genotype of plants are revealed. In all the studied forms, with an increase in the period of vernalization, the rate of plant development increased to varying degrees, the total number of stems, the productive stem and the length of the spike decreased.

Pathogenicity of Phytophthora × alni Isolates Obtained from Symptomatic Trees, Soil and Water against Alder

Phytophthora alni complex (P. × alni, P. × multiformis, P. uniformis) are pathogens attacking alder seedlings and trees, causing significant losses in nurseries and natural tree stands. Decay of alder trees has been observed in Poland for over a dozen years. Overall, 25 Polish isolates of P. × alni obtained from symptomatic alder trunks, rhizosphere soil surrounding infected trees, and nearby natural streams were compared with isolates from symptomatic trunks obtained in France, Belgium and Hungary. Morphologic characterization of mycelium, vegetative and generative organs, temperature effect on mycelium growth, and their pathogenicity were studied. The mycelium growth rate of isolates from symptomatic plants was fastest on Carrot Agar (CA) medium, and from soil and water on Vegetable Agar (V8A) medium. The sizes of zoosporangia varied depending on their origin. The isolates that originated from the soil had the largest zoosporangia. The diameter of the oogonia and antheridia did not differ regardless of their origin. The results of pathogenicity tests of P. × alni isolates obtained from different sources showed that the soil isolates were the most aggressive in each test, followed by the isolates from the trunks and water. A simple test of leaf colonization can give an idea of the aggressiveness of the isolate towards the shoots and roots. No morphological or physiological markers of aggressiveness have been found.

Evaluation of Siberian Stone Pine Plantations at the End of the First Age Class

The 40-year-old plantations of Siberian stone pine laid out as a permanent seed plot have been studied. The research purpose is to study the integrity, state and main forest inventory parameters of the Siberian stone pine plantations on the southern line of the species range at the end of first age class; to determine the role of natural renewal of trees and shrubs on the development of the Siberian stone pine plantations; to improve process solutions for efficient renewal of high-value biological resources. The research uses the methods generally accepted in forestry, forest science and forest inventory. It is found that the integrity of Siberian stone pine on the site is about 31 % (678 pcs/ha), wherein 406 pcs/ha are without damage to the trunk. Only about 25 % of Siberian stone pine trees grow under low shade, the rest of them are constantly shaded by natural renewal and have varying degrees of suppression. No generative organs were found in 44-year-old Siberian stone pine trees. At the initial stage of plantations growth, the main factor negatively affecting the integrity and state of trees is the damaging of Siberian stone pine by moose. Traditional improvement thinning with leaving stumps that produce many shoots of deciduous species attracts moose to the site in winter, where they use young growth of deciduous species and the covered with needles part of Siberian stone pine as forage. Subsequently, in the absence of tending, natural renewal negatively affects the Siberian stone pine trees, inhibiting growth and formation. It is necessary to remove the negative influence in the mixed biocenosis in order to prevent further deterioration of the Siberian stone pine state. This requires completely different technological solutions for forestry activities such as ringing or injection of trees of natural renewal, causing drying at the root, which significantly reduces or eliminates the emergence of deciduous young growth. This will decrease the attractiveness of the site for moose and minimize their impact on Siberian stone pine. The clear drying of surrounding trees will enhance the illumination of Siberian stone pine crowns and improve their soil nutrition, ensuring good root, trunk, and crown growth and accelerating the beginning of the formation of generative organs. These technical solutions can be used throughout the forest zone for the artificial cultivation of the high-value species – Siberian stone pine. For citation: Terekhov G.G., Andreeva E.M., Stetsenko S.K. Evaluation of Siberian Stone Pine Plantations at the End of the First Age Class. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 56–68. DOI: 10.37482/0536-1036-2021-6-56-68

Evaluation of interaction in the system "genotype of stock-scion/stock combinations of apple tree - habitat" at temperature stresses of the summer period in the Krasnodar Territory

The yield of fruit crops depends significantly on the climatic conditions of growing. High-temperature stresses of the summer growing season can lead to a decrease or even death of the crop. In the Krasnodar Territory, more and more new records of the onset of high temperatures are observed in the summer months, when the average daily temperature exceeds the climatic norm by 4-7 degrees. The purpose of the study is to study the sustainability of apple tree trips for summer high-temperature stresses, an assessment of the interaction in the system "Genotype of stock-scion/stock combinations of apple tree-habitat" in the conditions of a changing climate, as well as identifying the rootstocks that are most adapted to the soil-climatic conditions of the South of Russia. The relevance of the work is due to the enhancement of harmfulness of high-temperature stresses during the passage of the most important stage of laying the generative organs of the future harvest and ripening the current. An assessment of the drought-resistance of the apple trees in conditions of an elevated temperature background was carried out. Apple tree Prikubanskoy cultivar on semi-dwarf rootstock CK 2 and dwarf rootstock M 9 and CK 7, had the greatest leaf boom and their better water-holding ability. The most productive were the trees on the M 9 and SK 7 stocks. In the trees on the semi-dwarf stocks, the highest and steadily growing yield was on the SK 2 stock. Consequently, the implementation of genetic-physiological systems of adaptability of drought-resistant briefings determined the level of yields of the graft trees of the apple tree. The use of apple trees with a high biopotential of resistance to abiotic stress is an element of biologized compensation for the damaging effect of climatic stressors in the ecologized technology for the production of gardening products.

Assessment of the decorative qualities of species of the genus Pinus L. in the conditions of the European part of Russia

The paper presents the results of a study of the decorativeness of pines, which are actively grown on the territory of the European part of Russia. Decorativeness is based on the visual perception of plant habitus. The state of the habitus depends on the genotype and adaptive characteristics in certain growing conditions. The study examined 25 decorative features of 56 species. 24 traits were related to vegetative and generative organs. 1 trait was assessed by the method of weight taxonomy as an indicator of originality of all species for 24 traits. Studies have shown that the total score on a 100-point scale of decorativeness in the studied pines varies from 40 in Pinus heldreichii Chirst and Pinus waschoensis Mason & Stockwell to 68 in Pinus patula Schltdl. & Cham. The research results can be applied when choosing species for cultivation on landscaping objects to increase their aesthetic appeal.

The structure of chlorenchyma and plastid apparatus of the generative organs at chloridoid grasses

The structure of the chlorenchyma and the spatial forms of assimilative cells are considered in the glumesof spikelets at the xerophytes Cleistogenes squarrosa and Tripogon chinensis and the halophytes Aeluropus intermedius andCrypsis aculeata with C4-photosynthetic metabolism (NAD-ME biochemical group). The structure of the photosynthetictissue of the rachis was also studied in Tripogon chinensis. It is shown that the generative and vegetative organs of chloridoid grasses are similar in the structure of the chlorenchyma, but differ in the degree of its development. In the glumes ofspikelets, it is less developed than in the leaves, and in the rachis, on the contrary, its presence is greater than in the stem.In the assimilatory tissue of generative organs, there is also a wide participation of longitudinally arranged cellular cellsconsisting of small, often numerous sections, which in their size are close to those in the leaves and stems.

Structure of Anther Epidermis and Endothecium, Production of Pollen, and Content of Selected Nutrients in Pollen Grains from Six Rubus idaeus L. Cultivars

Poland is the largest European Union producer of Rubus idaeus. This species provides insects with nectar and pollen from June to September. The rationale behind the present research is the increasing commercial production and the use of food attractants for pollinators increasing fruit yields. The intensive search for phytochemicals applicable in industry and phytotherapy together with the unavailability of data on anther epidermis and endothecium structure justify undertaking these investigations. The pollen mass, the content of elements, protein, and fat, as well as the composition of amino acids and fatty acids in the pollen of six R. idaeus cultivars were compared. In terms of pollen production, the cultivars ranked as follows: ’Pokusa’ < ‘Polana’ < ‘Glen Ample’ < ‘Polka’ < ‘Radziejowa’ < ‘Laszka’. The protein content (26–31%) in the pollen indicates its good quality and high attractiveness. Exogenous amino acids, including those with dietary importance, constituted a substantial proportion (33–39%). The content of MUFAs and PUFAs was 32–47% and 3.7–9.1%, respectively. The presence of elements that determine the nutritional value and proper development of pollen was detected in the mineral composition of the exine. The data on the epidermis and endothecium structure provide new information about the micromorphology, anatomy, ultrastructure of and generative organs and auxiliary criteria in the taxonomy of related species.

Resistance of generative organs of sweet cherry to spring frosts after artificial freezing

Aim. The purpose of this research was to study the sustainability of Institute bred sweet cherry cultivars to spring frosts during flowering by the method of artificial freezing and to identify resistant cultivars.Material and Methods. Seven Institute bred sweet cherry cultivars were studied: 'Adelina', "Malysh", "Orlovskaya Rozovaya", "Orlovskaya Feya", "Podarok Orlu", "Siyana" and "Trosnyanskaya". Spring frosts were simulated in an "Espec" PSL-2KPH climate chamber in early May at -1°, -2°, -3° and -4°C. At each temperature regime, 100 pcs of flowers and buds of each cultivar were taken in 3-fold repetition. Temperature was lowered at the rate of 1°C per hour. The duration of exposure to negative temperatures was 3 hours.Results. Damage to the stamens and pistils was assessed by the darkening of the tissues. In buds and blooming flowers after frosts, the pistils were first damaged but the stamens were not. Resistance to spring frosts decreased with the phenological development of the cherry's generative organs. The beginning of damage to the flowers as a result of the artificial freezing was noted at a temperature of -1°C. At the same time, the high stability of cherry buds was noted. Modeling frosts of -2°...-4°C increased the number of dead flowers and buds. The resistance of sweet cherries to spring frosts was found to depend on the genotype and stage of development of reproductive organs. A different sum of active temperatures for the beginning of flowering and ovary formation was noted, indicating the onset of phenological phases in which generative organs are susceptible to spring frosts.Conclusion. The experiment made it possible to distinguish a medium-resistant cultivar "Malysh" which was resistant to spring frosts. Weakly stable genotypes were "Orlovskaya Rozovaya", "Orlovskaya Feya", "Trosnyanskaya" and "Siyana". Unstable cultivars were "Adelina", and "Podarok Orlu". During the formation of the ovary, the greatest potential for resistance to spring frosts was shown by "Podarok Orlu".

Methods for Increasing the Corn Yield per Grain when Cultivated under Conditions of Unstable Moistening Zone

Кукуруза занимает второе место среди зерновых культур, обеспечивая более четверти валового сбора зерна в мире. Важнейший аспект формирования высоких урожаев – технология возделывания культуры, одним из главных элементов которой является основная обработка почвы. Исследования по влиянию двух приёмов обработки почвы (дискования и вспашки) при возделывании трёх гибридов зарубежной и российской селекций (Монсанто DKS 3939, AS-201, Машук 171)на фотосинтетическую деятельность и урожайность кукурузы проводили в условиях Карачаево-Черкесской Республики в 2016–2018 гг. В результате проведённых исследований установлена прямая зависимость между площадью листьев и урожайностью. Максимальную урожайность (7–8 т/га) на вариантах, где применялась вспашка, показал гибрид AS-201. Доказано преимущество вспашки в формировании площади листовой поверхности, о чём свидетельствуют полученные данные и их математическая обработка – BFф> F057,8 : 2,12. Это подчёркивает отзывчивость кукурузы на глубокие отвальные обработки почвы, направленные в полной мере на формирование корневой системы, как следствие – потребление элементов питания и влаги, способствующих формированию вегетативной массы растений, закладке генеративных органов и, в конечном итоге, получению более высокой урожайности в сравнении с поверхностными обработками, такими как дискование. Гибриды Монсанто DKS 3939 и AS-201 на фоне вспашки формировали максимальную продуктивность в благоприятном 2018 году. На вариантах с дисковым лущением такой фактор, как условия года, проявил себя незначительно. Согласно данным исследователей, от основной обработки на 12,2% зависит урожайность культур севооборота. Управляя этим фактором, можно увеличить продуктивность кукурузы на 23…25%. Поэтому правильный выбор системы основной обработки почвы – действенный рычаг повышения урожайности, особенно в современных условиях. При возделывании гибридов кукурузы для получения высоких и стабильных урожаев авторами рекомендуется в качестве основного приёма обработки почвы использовать вспашку. Corn ranks second among cereals, providing more than a quarter of the world's gross grain harvest. The most important aspect of the formation of high yields is the technology of cultivating the crop, one of the main elements of which is the main tillage. Studies on the influence of two tillage techniques (disking and plowing) in the cultivation of three hybrids of foreign and Russian breeding (Monsanto DKS 3939, AS-201, Mashuk 171) on photosynthetic activity and corn yields were carried out in the conditions of the Karachay-Cherkess Republic in 2016–2018. As a result of the conducted researches a direct relationship between the area of leaves and yield was established. The maximum yield (7–8 t/ha) in variants where ploughing was used was shown by the hybrid AS-201. The advantage of plowing in the formation of the leaf surface area has been proved, as evidenced by the obtained data and their mathematical processing – BFf > F05 7.8 : 2.12. This emphasizes the responsiveness of corn to moldboard soil cultivation, fully aimed at the formation of the root system, as a result the consumption of food compounds and moisture elements contributing to the formation of vegetative mass of plants, laying generative organs and, ultimately, obtaining higher yields compared to surface tillage such as disking. Hybrids Monsanto DKS 3939 and AS-201 against the background of ploughing formed maximum productivity in a favorable 2018. On variants with disk husking such a factor as the conditions of the year showed itself insignificantly. According the data of researchers, the yield of crop rotation crops depends on the main tillage by 12.2%. By controlling this factor, one can increase the productivity of corn by 23...25%. Therefore, the correct choice of the main tillage system is an effective lever for increasing yields especially in modern conditions. When cultivating corn hybrids to produce high and stable yields, the authors recommend using ploughing as the main method of tillage practice.