Generative Buds Research Articles

Adaptability of early flowering ornamental peach cultivars

To assess the adaptive potential of very early, early and early-medium flowering cultivars of ornamental peach, their frost resistance taking into account the rate of microsporogenesis, susceptibility to blossom blight, leaf curl and powdery mildew were assessed in connection with their use in breeding and landscaping. According to the results of freezing, it was revealed that the early-middle flowering cultivars subgroup showed greater frost resistance. When exposed to -16 °C in February, the number of live buds in different cultivars varied from 0 to 42 % in 2020 and from 13.64 to 95.65 % in 2021, because they were at later stages of development. The temperature of -10°C in March 2020 had a significant detrimental effect on the opened buds and blossoming buds of most genotypes. The maximum percentage of live buds (48.08-64.21 %) was noted in cultivars at the stage of the appearance of sepals. Frost -3°C at the end of March 2019 before flowering was weak: the number of live buds varied between 79.22-100 % in many cultivars. Three early-flowering cultivars with the highest frost resistance of generative buds (Lel, Frezi Grant and Ruthenia) were identified during February freezing and 3 cultivars (Lel, Miraisikl 2/4 and Ruthenia) during March freezing. Their use in regions with similar frosts in the late winter and early spring periods does not significantly reduce the ornamental value of plants. An assessment of susceptibility to the main fungal diseases showed that early-flowering cultivars are most sensitive to the causative agent of blossom blight. The cultivar Snezhnaya Koroleva showed the least susceptibility to the three studied pathogens, to two pathogens – Lel, Zhisele (to blossom blight and leaf curl) and Lyubava (to blossom blight and powdery mildew). This allows them to be more widely used in landscaping and, depending on breeding tasks, to be used in breeding as sources of tolerance.

Изучение зимостойкости абрикоса в контролируемых условиях

Abstract. The purpose of the research is to study the winter hardiness of apricot cultivars and hybrids and identify the most resistant ones to damaging factors of the winter period for use as sources for a given trait in breeding. Methods. The studies were carried out by artificial freezing using a climate chamber. Results. It was determined that apricot cultivars ‘Abrikos iz Kitaya’, ‘Agafonovskiy’, ‘Vostochno-Sayanskiy’, ‘Kunach’, ‘Lel’’, ‘Oblepikhovyy’, ‘Orlovchanin’, ‘Sardoniks’, ‘Triumf severnyy’ and hybrids 21183, 23659, 23688, 23797, 24071 and 24206 they have the component I of winter hardiness. ‘Orlovchanin’, ‘Triumf severnyy’ and hybrids 24071 and 24206 were characterized by maximum frost resistance (the component II of winter hardiness). ‘Agafonovskiy’, ‘Vostochno-Sayanskiy’, ‘Desertnyy’, ‘Oblepikhovyy’, ‘Triumf severnyy’ and 24206 had the ability to maintain frost resistance when the temperature droped to –17 °C after a three-day thaw of +2 °C (the component III of winter hardiness). It is important to note the average level of frost resistance of generative buds in ‘Abrikos iz Kitaya’, ‘Kunach’, ‘Orlovchanin’, ‘Podarok Vekhovu’, ‘Sardoniks’, ‘Khabarovskiy’ and hybrids 21183, 23659, 23688, 23797, 24071. At the end of winter, ‘Abrikos iz Kitaya’, ‘Agafonovskiy’, ‘Vostochno-Sayanskiy’, ‘Desertnyy’, ‘Oblepikhovyy’, ‘Orlovchanin’, ‘Sardoniks’, ‘Triumf severnyy’, ‘Khabarovskiy’ and hybrids 21183, 23797, 24071, 24206 were able to restore frost resistance at a temperature of –25 °C after a three-day thaw of +2 °C and re-hardening (component IV of winter hardiness). Scientific novelty. As a result of artificial freezing, perspective cultivars ‘Orlovchanin’, ‘Triumf severnyy’ and hybrids 24071, 24206 characterized by the greatest frost resistance potential for the main components of winter hardiness were identified for further use as sources for this trait in breeding.

Morpho-physiological characteristics of plants and biochemical parameters of rowan berries, common rowan, and domestic rowan grown in the conditions of the Northern Forest-Steppe of Ukraine

The relevance of this subject lies in the comparative evaluation of different species of rowan to increase their significance and use in the system of ornamental and fruit horticulture, in the technologies of processing plant raw materials, and in the production of products for healthy nutrition. The purpose of the study is to examine the morpho-physiological characteristics of plants and the biochemical parameters of the fruits of different species (varieties, forms) of the genus Sorbus. Based on the results of practical research, original data on the morphology and economic characteristics of representatives (varieties and forms) of Sorbus intermedia Pers., Sorbus aucuparia L., Sorbus domestica L. are presented. Biological properties of the plants and biochemical parameters of the fruits are highlighted. It is established that all studied representatives of the genus Sorbus have high winter hardiness (1.5 points according to S.Ya. Sokolova), in addition, Scandinavian rowan plants have high drought resistance (4.5 points according to S.S. Pyatnitsky) compared to common rowan plants. Phenological observations of plants of different rowan species allowed for the conditions of the Forest-Steppe of Ukraine to determine the time of onset of ontogenesis phases: development of vegetative buds, appearance of leaves, shoot growth, budding, and flowering, formation and development of ovaries, ripening and fruiting, changes in leaf colour, and leaf fall. Subphases that more accurately characterise the time of onset, peak, and end of a certain phase of development have also been identified, which is a scientific achievement for strategies in the system of ornamental and fruit horticulture. The growth intensity of varieties and forms of representatives of the Sorbus genus in height was studied, and the general condition of plants for viability is evaluated. Preparatory work on the preparation of rootstocks, the selection of scions, and grafting allowed the formation of model plants in the collection nursery and additional assessment of their growth strength, the onset and passage of individual phases of development, assessment of drought and winter hardiness, age of fruiting, and more. Biometrics and descriptions of stem, branches, vegetative and generative buds, leaves, inflorescences, and fruits are also conducted. The taste characteristics of the fruits are described in the materials of the paper. Biochemical analysis of the fruits allowed establishing their suitability for processing and the production of products for healthy nutrition

Study of frost resistance of own-rooted and grafted cherry plum under controlled conditions

Studies on the frost resistance of cherry plum were carried out in 2022-2023 at the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery in laboratory conditions by artificial freezing in the climatic chamber EW 1070. The objects of research were plants of the varieties Shatyor, Zlato Skifov and Kubanskaya Kometa, own-rooted and grafted on clone rootstocks SVG-11-19 and 13-113. The purpose of the research is to study the influence of the method of reproduction and the shape of the rootstock on the frost resistance of buds and tissues of annual branches of cherry plum and to identify the most frost-resistant graft-rootstock combinations. It was found that after freezing at t = -30 °C, more than 50 % of generative rudiments remained viable in both years of research in the Kubanskaya Kometa variety, in the Zlato Skifov variety – from 30 to 45 %, in the Shatyor variety – on average 49 %. The limits of changes in the frost resistance of generative buds of varieties depending on the rootstock are shown: in the Kubanskaya Kometa variety – from 46,5 % (13-113) to 68,9 % (SVG-11-19), in the Zlato Skifov variety – from 37,6 % (own-rooted) to 45,3 % (SVG-11-19), and in the variety Shatyor – from 41,4 % (roots) to 45,3 % (SVG-11-19). When using the clone rootstock SVG-11-19, the safety of generative rudiments increased by 17 % compared to the root variant. Damage to vegetative buds and tissues of annual branches up to 1-3 points was caused by temperature t = -35 °C. The most frost-resistant combinations were the Kubanskaya Kometa/SVG-11-19 and the Shatyor/SVG-11- 19, in which kidney and tissue damage was less than 1 point.

QTL mapping of generative bud break to promote breeding of apple cultivars resilient to climate change

QTL mapping of generative bud break to promote breeding of apple cultivars resilient to climate change

Manifestation of multiple racemes trait of black currant

The results of the evaluation of the genetic collection of black currants on the multiple racemes trait for increasing the productivity of the crop in the conditions of the Bryansk region are presented. The index of the number of racemes with fruiting on one shoot node was studied. It has been shown that under the conditions of the southwestern part of the nonchernozem belt of Russia (Bryansk region), formation of one generative bud in the axils of leaves is typical for the crop, but there are forms in which some nodes are capable of forming 2-3 racemes with fructification. It has been found that out of 132 varieties of the genetic collection studied, 116 specimens (87.9%) formed nodes with 1-2 generative buds. As a result of the studies, varieties with 3-4 inflorescences on the nodes capable of bearing fruit were selected (Dar Smolyaninova, Debryansk, Bryansky Agat, Selechenskaya 2, Ladushka, Orlovsky Vals, Istok, Chudnoe Mgnovenie, Yubileinaya Kopanya, Vera, Chernavka, etc.). Their use in further crosses will produce more productive genotypes. The most productive combinations of the crosses have been identified according to the yield of progeny forming 2-4 generative formations on one node (63-35-1 × Litvinovskaya, Svityazyanka × Selechenskaya 2, Debryansk × Dar Smolyaninova, Chudnoe Mgnovenie × Golubichka, 10-141-2 × Partizanka Bryanskaya, Debryansk × Litvinovskaya). Promising selected forms (3-63-01, 5-82-02, 8-69-01, 5-45-02, 4-18-01, 4-94-1, 4-18-02, 2-30-01, etc.), which combine the multiple racemes feature with other economically valuable indicators (resistance to pathogens, large fruits, dessert taste of fruits, number of berries in the raceme, their one-dimensionality) are highlighted.

Зимостійкість нових перспективних сортів та елітних форм груші (Pirus communis L.) Інституту садівництва НААН України

The results of determining the winter and frost resistance of new promising varieties of pears of the IH NAAS selection Vezha muscatna, Kytaiskyi likhtaryk, Panianka and elite forms 4-24 (Dekanka muscatna), 4-79 (Vodokhreshche), 17-98 (Suvenirna), 17-103 (Olkhotivska). Temperatures of -25...-30 °C during the most important periods of pear wintering are not devastating for all studied varieties and forms. Low temperatures (-25...-30 °C) damage all the tissues of the tops of the shoots somewhat more than the middle part. In addition, damage by the pear leafhopper (Psylla ріricola Forst.) contributed to the decrease in winter hardiness of Panianka, Kytaiskyi likhtaryk and Vyzhnytsia varieties and forms 17-98 (Suvenirna). According to the complex of features included in the concept of winter hardiness, the Vezha muscatna variety and the elite forms 4-24 (Dekanka muscatna) and 4-79 (Vodokhreshche) stand out on the positive side. The freezing of tissues of the sub-bud zone of generative buds has a significant practical effect on the formation of the next year's harvest. This zone is a kind of biological safeguard against premature sprouting of buds in January-February. Previous studies have also established that in the sub-bud zone, at the time of natural dormancy, in the zone of the conducting vessels connecting the bud to the shoot, the xylem part, where the vascular bundle will then pass, is filled with unstructured parenchyma cells. The formation of a vascular bundle in this zone is preceded by a double restructuring - the transformation of parenchymal cells into cambial cells (long-term warming to +5…+10 °С in February), and the latter into spiral vessels (beginning - mid-March). Restructuring periods are very sensitive to low temperatures, and if at this time they drop to -10...-12 °С, a vascular bundle is not formed, without which the development of a fruit bud is impossible, which leads to a significant decrease in yield. These conclusions are also confirmed by our observations: in the formation of the pear crop, the coincidence of unfavorable weather conditions in January-February and their influence on generative buds are sometimes more noticeable than during spring frosts, which in our conditions occur mostly after the pear has blossomed, and yarrow is more frost-hardy than flowers. Key words: pear, variety, frost resistance, winter resistance, bark, cambium, wood, core, bud.

Frost hardiness of apple generative buds during dormancy

<p class="042abstractstekst">The success of apple production is influenced by frost damages. Occurrence of extreme temperatures is increasing worldwide because of global warming, so the risk of frost damages is also increasing in apple orchards during dormancy and blooming time. In our work the frost hardiness of flower buds of eight apple cultivars was observed with artificial freezing tests during four subsequent dormancy periods in Hungary. The studied cultivar assortment contained two standard commercial cultivars (‘Gala’, ‘Idared’), two scab-resistant cultivars from abroad breeding programmes (‘Florina’, ‘Prima’) and four new Hungarian multi-resistant (mainly scab-resistant) cultivars (‘Artemisz’, ‘Cordelia’, ‘Hesztia’, ‘Rosmerta’). There were remarkable differences between cultivars and years from the aspect of frost hardiness of generative overwintering organs. At the end of hardening period, in January, the LT<sub>50</sub> values of flower buds were between -22.4 °C and -30.4 °C according to cultivar and year. LT<sub>50</sub> means the temperature causing 50 % frost damage in the flower buds of the certain cultivar in the certain time. ‘Gala’ and ‘Florina’ were the most frost hardy, while ‘Prima’, ‘Cordelia’ and ‘Idared’ the most sensitive to frost. Cold hardiness values of flower buds of ‘Artemisz’, ‘Rosmerta’ and ‘Hesztia’ cultivars were regularly between the values of two extreme groups. In winters with inappropriate weather the generative overwintering organs were unable to reach the genetically possible frost hardiness of them.</p>

Consequences of the Reproductive Effort of Dioecious Taxus baccata L. Females in a Generative Bud Removal Experiment-Important Role of Nitrogen in Female Reproduction.

Dioecious species differ in the pattern and intensity of male and female reproductive investments. We aimed to determine whether female shoots deprived of generative buds show biochemical features, indicating their less-pronounced reproductive effort. For this purpose, the same branches of mature Taxus baccata females were deprived of generative organs. In the second and third years of the experiment, measurements were made in every season from the control and bud-removed shoots of females and control males. Bud removal caused an increase in nitrogen concentration almost to the level detected in the needles of male specimens, but only in current-year needles. Moreover, differences between male and control female shoots were present in the C:N ratio and increment biomass, but they disappeared when bud removal was applied to females. Additionally, between-sex differences were observed for content of phenolic compounds, carbon and starch, and SLA, independent of the female shoot reproductive effort. The study revealed that nitrogen uptake in seeds and arils may explain the lower nitrogen level and consequently the lower growth rate of females compared to males. At the same time, reproduction did not disturb carbon level in adjacent tissues, and two hypotheses explaining this phenomenon have been put forward.

ОСОБЕННОСТИ СТРУКТУРЫ КРОНЫ И СТРОЕНИЯ ПОБЕГОВ ПИХТЫ СИБИРСКОЙ РАЗНОЙ СЕКСУАЛИЗАЦИИ

One of the main effects influencing the structure and functioning of terrestrial organisms is gravity. Siberian fir turned out to be extremely sensitive to the action of gravity - the crown of adult trees is differentiated according to the type of sexual shoots along the “top-down” axis, the length of the sexual tiers along the tree axis varies significantly. The research was conducted in the territory of the National Park "Krasnoyarskie Stolby", located on the northwestern spurs of the Eastern Sayan, on the Kuysum (Krasnoyarsk) Ridge, the territory belongs to the Eastern Sayan mountain taiga region of pine-cedar fir forests. The study has shown differences in the structural and functional parameters of fir shoots of different "sex". Changes in the biometric parameters of generative and vegetative shoots and needles are due to the peculiarities of their anatomical structure. Determination of anatomical and morphological parameters of shoots and needles was performed on model trees with average taxonomic characteristics and without visual signs of damage. It is assumed that the peculiarities of shoots structure of different sexualization are caused by their functional role. More powerful generative shoots at the tree top already in the first year of development (formation of generative buds) provide the maximum inflow of nutrients to reproductive organs. The role of the physical imprint in the structural features of individuals of the species at the cellular and tissue levels is discussed.

Assessment of Physio-Chemical, Nutritional and Enzymatic Activities in the Bud in Relation to Flowering Behaviours of Different Alternate Bearing Mango (Mangifera indica L.) Cultivars

ABSTRACT Most of the commercial mango cultivars have the tendency of alternate bearing, which significantly reduces the productivity and profitability of the crop. But literatures on the exact physiological mechanism behind flowering in mango during on and off year are very scanty. Hence, an attempt has been made to understand the physio-chemical and nutritional basis for on- and off-season bearing in different commercial mango cultivars. Specific leaf weight and net assimilation rate were increased marginally at panicle emergence stage as compared to bud break stage. Carbohydrate and soluble protein contents in the bud at bud break stage were estimated significantly higher in on-season trees (195.25 µg g−1 and 5.73 mg 100 g−1, respectively). Activities of oxidative enzymes (polyphenol oxidase, peroxidase, catalase) in the bud were recorded significantly higher in off-season trees. Nitrogen, phosphorus and potassium contents in the bud at bud break stage were estimated significantly higher in off-season trees (1.52, 0.22 and 0.53%, respectively), although secondary and micronutrient contents were estimated higher in on-season one. Finally, the generative buds per branch were estimated significantly higher in on-season trees (90.66%) as compared to off-season one (18.68%). Hence, it can be concluded that increased physio-chemical attributes in the bud at bud break stage has direct relation with panicle emergence in mango. However, increased macronutrients and higher activities of oxidative enzymes leads to off-season bearing, although increased secondary and micronutrient contents in the bud at bud break stage are helpful for improved flowering in mango.

MORPHOLOGICAL CHARACTERISTICS OF BLUEBERRY BUDS OF SOME VARIETIES INTRODUCED IN BELARUS

The article indicates morphological features of vegetative and generative buds of 20 varieties of highbush and 3 varieties of halfhighbush blueberry. Generative buds are laid in the upper part of branching shoots, less often on replacement shoots. Flower buds are much larger than vegetative buds, ovoid, from 3.9 (Jersey) to 6.5 mm (Hardyblue) long, from 2.0 (Herbert, Patriot) to 2.7 mm in diameter (Reka). Depending on the varietal specificity, on average, from 1.3 (Carolinablue) to 6.3 (Rubel) generative buds are formed on one shoot of highbush blueberry branching. The peak number of fruit buds can reach 11 pcs/shoot (Rubel). Vegetative buds are cone-shaped, from 1.8 (Bluecrop, Darrow, Herbert) to 2.8 mm (Jersey) long, from 1.1 (Blueray, Darrow, Jersey, Northblue, Rubel, Weymouth) up to 1.5 mm (Bluetta, Coville) wide. Depending on the variety, on average, from 4.8 (Nelson) to 8.4 (Weymouth) growth buds are laid on the branching shoot. The ratio of vegetative to generative buds on one run varies on average from 1.0 (Rubel) to 6.7 (Bluetta). The linear parameters of the kidneys increase from the base of the shoot to its top.

THE ANNUAL CYCLE OF DIFFERENTIATION OF THE RUDIMENTS OF PEACH FLOWERS AFTER THE SEVERE WINTER OF 2020-2021

The article sets the timeframe for the main phenological stages of peach, as well as the required amount of effective temperatures above +5 °C for their passing and growing season length based on the example of the variety of Belarusian selection Loiko.
 The terms of the beginning of an organogenesis of flower rudiments after a severe winter and damage of generative buds, 
 skeletal branches are outlined. The peculiarities of the differentiation process during the growing season and the required amounts of effective temperatures for each stage of flower organogenesis in the central zone of Belarus are presented.
 The data obtained show that in late November the process of differentiation in most generative buds stops at stage VII b
 with a well-defined rudiment of the pistil and its clear differentiation into stigma and style. In the case of thawing during the winter, the process of organogenesis does not stop, and in February the development of flower buds in the generative buds
 reaches stage VIII with the formation of the ovary and the growth of stamens with anthers of characteristic shape.

Адаптивність зарубіжних сортів абрикоса (Armeniaca vulgaris Lam.) до дії низьких температур в умовах Київської області

The authors present the results of determining the winter hardiness and frost resistance of the three introduced cvs Ledana, NJA-19 and Leskora, grafted on the rootstock Pumiselect, by means of combining field and laboratory methods. The research was conducted in the apricot of the orchard educations training laboratory "Fruit and Vegetable Plantation" NULES of Ukraine and in the Laboratory of the Plant Physiology and Microbiology of the Institute of Horticulture NAAS in the cold periods of 2019 2021. One-year increments with buds were frozen in the refrigerator CRO/400/40 by means of reducing the temperature gradually to -25 and -30 ºC. The evaluation was carried out on the basis of the microscopic analysis according to the six-point scale (from 0 to 5 points). The critical damage of the generative buds of the plants of all the investigated varieties was detected generative (3.4-5.0 points) in laboratory conditions under the above mentioned freezing temperatures. The damage of the Leskora and NJA-19 trees shoot tissue under -25 ºC was not critical, at the same time under -30 ºC the damage of all the strains mentioned organs was rather more severe. On the average during the explorations years in was Ledana that appeared the most susceptible under freezing to 25 and 30 ºC. In the cultivar Leskora plants were high winter – hardy while the Ledana trees were the least resistant ones. Under the temperature below -20 °C the researched crop trees generative buds proved to be frozen, especially in the increments lower part. The weather conditions in the investigations period caused the considerable introduced cvs harvest loss and the vegetative organs freezing but the plants renewed quickly during the vegetation period. The explorations have shown that the weather conditions in the Northern part of the Lisosteppe (Kyivshchyna) are critical for the apricot growing because of the low temperatures effect, their fluctuations in winter and possibility of the late spring slight freezes during flowering. It is strains Leskora and NJA-19 that are the most favorable for the cultivation in the similar conditions. They will ensure high crop under the suitable cultivation conditions and high agrotechnics.

FROST RESISTANCE OF THE COLUMNAR APPLE TREE THE METHOD OF DIRECT FREEZING

Frost stress strongly affects the spatial distribution of plants. Among various weather hazards, frost causes the greatest economic losses in agriculture. Among various environmental hazards, it is frost that causes the greatest economic losses in agriculture. Although frost severely limits life forms and creates enormous economic losses, it has not been studied as thoroughly as other biotic or abiotic stresses. Frost resistance can be affected by many factors, including microclimate, soil condition, plant height, but they must be studied in a complex. The purpose of the research was to select frost-resistant cultivars and hybrids of the columnar apple tree under the conditions of the Forest Steppe of Ukraine. The research was carried out during 2021–2022 at the V.L. Symyrenko Department of Horticulture of the National University of Life and Environmental Sciences of Ukraine. The experimental basis for conducting research was the columnar apple tree plantations of the Training Laboratory «Fruit and Vegetable Garden». Frost resistance was determined during the period of deep rest by the method of direct freezing of one-year increments. Freezing was performed in the laboratory of plant physiology and microbiology of the National Academy of Sciences of Ukraine. In the researched plantations, when the test samples were frozen at temperatures of -25 and -30 °C during deep rest, different resistance of varieties and shoot parts to low temperatures was found. In all cultivars and hybrids of columnar type apple trees, the apical bud and generative buds were the most vulnerable, and the tissues of the middle and upper part of the shoot were the most resistant to frost. The damage index during general freezing was the lowest in the cultivars Valuta’, Sparta’, Favoryt’, Bilosnizhka’, as well as in the hybrids 9/110 Mykhailivske’, 11/15(2)’ and 9/78 Viktoriia’; it was the largest in the Bolero’ cultivars. Freezing of experimental samples at temperatures of -25 and -30 °C did not result in frostbite, critical for plants. All studied cultivars and hybrids of columnar apple trees are recommended for further research and production. The obtained results will be interesting for both experienced gardeners and amateur gardeners who plan to grow columnar apple trees in their garden.

PRODUCTIVITY OF 20 YEAR PLANTS COLUMNAR APPLE-TYPE UNDER THE CONDITIONS OF KYIV REGION

Differentiation of generative buds is one of the most important biological processes of plant transition from vegetative to generative state. The study of the productivity of apple trees in the process of its formation, by analyzing the formation of rudimentary organs and their successive development into vegetative and generative organs, which are elements of productivity, allows to establish the features of this process in complex fruit formations of different ages. Knowing the level of influence of meteorological factors on the passage of II-XII stages of organogenesis, we can recommend more specific soil and climatic conditions for growing columnar varieties. Plants of columnar varieties of apple differ from traditional almost complete absence of lateral branching, the formation of crops on simple and complex rings (fruit formations), which are located on the trunk of the tree, as well as dwarf growth, early fruiting and high yields. In the studies, trees of columnar varieties on medium-sized rootstock 54-118 differed significantly in height, trunk diameter, crown width and density of fruit formations on the trunk. As the height of the trees increases, the number of fruit formations on the plant increases, resulting in an increase in the potential for higher yields. Considering the realization of reproductive potential in stages, we noted changes in the participation of different age areas of the trunk (complex rings) in the formation of the actual harvest. In the conditions of Kyiv region, columnar apple cultivars react differently to environmental conditions at certain stages of organogenesis. The efficiency of differentiation of generative buds of columnar varieties is influenced in one way or another by meteorological factors. For introduced varieties, the increase in the level of Σaсtt≥10, precipitation and average daily air temperature has a negative effect on the formation of generative potential at III-IV stages of organogenesis, as evidenced by the high negative correlation between the ratio of generative buds to their total number and these factors (r > -0.80–0.96). The influence of these meteorological factors on the varieties of Ukrainian selection is weak and moderate, which indicates the best adaptive properties of these varieties. The influence of the age of the trunk on the formation of plant productivity is minimal or absent (from 0 to 3%).

Comprehensive study of Malus genus resources for the creation of adaptive grades

The breeding renewal of the apple assortment in the conditions of southern fruit growing in Russia on the basis of domestic achievements is due to the acceleration of the breeding process associated with an in-depth study of the existing gene pool of culture, the widespread use of the samples most valuable in terms of the quality of the products obtained to create commercially demanded grades of regional breeding. The aim of the study is to isolate, on the basis of a long-term comprehensive study in the conditions of the Western Ciscaucasia, valuable specimens of the genusMalusto enhance the efficiency and accelerate the process of creating adaptive and high-quality grades of regional breeding. The work was carried out using generally accepted and modern programs and methods of variety study and selection of perennial fruit crops (apple trees). The long-term results of the study for 2010-2020 are summarized. in the conditions of the Kuban zone of the North Caucasian region of gardening of collection specimens of apple trees. Established that the increase in high-temperature stressors, the deficit in August of precipitation (28.2 mm) in recent years (2010-2020) has a negative impact on the growth, development and ripening of fruits, the laying of generative buds of the next year’s harvest. The weather conditions that have developed in the region, which are not sufficiently favorable for apple plants, make it possible to select drought-resistant, high-yielding, stably fruiting grades with commercially valuable fruits. Highlighted with high productivity potential diploids: 12/1-21-60, 12/2-20-22, 12/2-20-75 and triploids: 12/2-21-35, 12/2-20-56 (average yield 28.06-34.08 t/ha; total – up to 374.88 t/ha). Diploids were distinguished by large-fruited: Orpheus and 12/1-21-60 (average fruit weight 202.3-204.5 g, maximum – 224.8-278.8 g) and triploid varieties and elite forms (from the family of Idared × Balcgard 0247E): 12/2-21-35, 12/2-20-56, 12/1-21-27 (average fruit weight 201.4-317.9 g, maximum – 286.5-387.2 g).

Formation of a collection of magnolia (Magnoliaceae Juss.) in the Stavropol Botanical Garden

The purpose of the work is to study the ways of forming the collection fund of magnoliaceae in the Stavropol Botanical Garden named after V.V. Skripchinsky (SBG), to assess the current state of the collection and prospects for development. The relevance and practical significance of studying representatives of magnolias comes from the increased needs to expand the assortment of highly ornamental woody plants for landscaping settlements of the Stavropol Territory. The object of the study was the plants of the SBG collection. For reviewing the history of the introduction of magnolias the archival data and reporting documentation were used. Phenological indicators were recorded according to the generally accepted methodology for the botanical gardens of the USSR. The height of the plants was measured with a SUUNTO PM-5 altimeter. The work was carried out in 2020-2022. The SBG has been interested in magnolias since the first years of the garden’s creation (since 1959). As of 2021, there were 8 species and hybrid taxa from two genera of the Magnoliaceae family in the SBG collection, represented by 17 specimens. The life form is characteristic of the studied taxa: large shrubs (Magnolia kobus, M. liliifl ora, M. × soulangeana), low-stemmed (M. kobus, M. kobus var. borealis, M. × loebneri) and tall trees (M. acuminata), sometimes multi-stemmed (Liriodendron tulipifera). The article describes the characteristics of the magnolias available in the collection: their age, size, main phenological phases. The quality of flowering magnolias is influenced by a decrease in temperatures in the early spring period: prolonged cooling causes freezing of generative buds or “rusting” of petals. As a result of long-term study by the staff of M.A. Koltsova, A.F. Koltsov, E.V. Pyatko, the species M. acuminata, M. kobus, M. kobus var. borealis, M. liliiflora are recommended for further use in landscaping in the Stavropol region. In 2021, work continued on the formation of a collection of magnolias: two-year seedlings of 9 varieties and 2 species of deciduous magnolias were obtained for further introduction study.

Research of the mechanisms of winter resistance in apricot generative buds

Research of the mechanisms of winter resistance in apricot generative buds

Оценка состояния некоторых сортов Hydrangea macrophylla (Thunb.) Ser. после зимовки в условиях средней полосы России

Hydrangea macrophylla (Thunb.) Ser. is one of the most popular ornamental crops, used in landscape design. This article represents the study of the variety resistance of species and influence their of climatic change. In that sense the effective technology of plant shelter for the winter hardiness can be considered as a successful important factor for the promotion of this crop in northern area. Wherefore we consider in a comparative analysis of H. macrophylla varieties Forever & Ever Blue and Peppermint, which we carried out after winter hardiness in the conditions of central Russia. The most reliable and proven way to shelter for winter of hydrangea is the shelter of lutrasil, which contributed to an increase in the viability of shoots and the amount awakened buds, and also provided the better growth of shoots during the month. The highest percentage of overwintered shoots (77,8%), the amount of vegetative and generative buds (19,3±1,3 сm и 9,6±0,7 сm., respectively) and the total growth of shoots in spring (10,2 cm) were characteristic for variety Forever & Ever Blue for using lutrasil as a shelter. Keywords: HYDRANGEA MACROPHYLLA, VARIETIES, WINTER HARDINESS, FROST RESISTANCE, VIABILITY, SHELTER