Cherry Varieties Research Articles

Comparative Study on the Effect of GiSelA 5 Rootstock Propagation Methods on Sweet Cherry Growth and Physiology

The basis of orchard production is rootstocks that reduce the vigor of sweet cherry trees. However, not all rootstocks for this species can be easily propagated using traditional methods of stooling or cutting. Some of these must be propagated using the in vitro method. This is expensive and, consequently, increases the price of maiden sweet cherry trees. Our experiment assessed the growth of maiden trees of selected sweet cherry varieties (‘Bellise’, ‘Earlise’, ‘Lapins’, ‘Vanda’) depending on the method of propagation of a semi-dwarf GiSelA 5 rootstock. Additionally, the intensity of physiological processes taking place in the obtained maiden trees was also examined. The experiment compared one type of GiSelA 5 rootstock, obtained using a cheaper softwood cuttings method, with another rootstock propagated using an in vitro method. During the two years of study, there were no significant differences in the percentage of maiden trees obtained in the case of the propagation methods for both types of rootstocks, ranging from 77.43% to 87.74%. The vigor of maiden tree growth in the first year of this study was stronger than in the second year. In particular, the stem diameter of maiden trees varied from 7% to 39%, depending on the variety considered. With the exception of one variety, maiden trees produced from a rootstock propagated by stem cuttings were characterized by a larger stem diameter for the three varieties, ranging from 23% to 29%, and by a greater number of side shoots, ranging from 73% to 172%, compared to those from in vitro. Additionally, when using the stem cutting method of propagation, the rootstocks had a better developed root system, except for the ‘Earlise’ variety. However, most often, no significant differences were found between the methods of propagation regarding the fresh weight of the maiden trees and leaves and their leaf blade area. The activity of physiological processes of maiden sweet cherry trees varied, and no constant regularities were found. In the second year of the experiment, maiden trees were more often characterized by lower levels of net photosynthetic intensity and internal CO2 concentration, which was associated with worse growth results. Based on the collected results, it is recommended to propagate the considered rootstock using stem cuttings, which yields maiden trees with similar and sometimes even better growth parameters than those propagated using the in vitro method.

Фенологические особенности развития сортов вишни в меняющихся погодно-климатических условиях

Annotation. Cherry is a stone fruit crop cultivated in almost all regions of Russia. Currently, there is a significant change in weather and climatic conditions, their impact leads to a shift in the phenological phases of plant development and to disruption of the stages of organogenesis. In this regard, there is a need to study the passage of phenological phases of cherry development in the changing weather and climatic conditions of the southern region. The research was carried out on the basis of the collective use center (CUC) “Genetic collection of fruit crops” in the period 2020-2023 in the Kuban horticulture zone of Krasnodar region. The objects of research were 11 varieties of sour cherries of various ecological and geographical origins. Planting scheme is 5x3 m, rootstock is antipka seedlings. During the research, the sum of active temperatures during the cherry growing season was determined, which determines the occurrence of the main phenological phases of development of cherry varieties in the annual development cycle. It was established that over the years of research, on average, the sum of active temperatures exceeded the long-term average by 551,7 °C. It was determined that during the research period the phenological phase “beginning of growing season” of cherries took place at a sum of temperatures of 32.8-54.2 °C. The phenological phase of “beginning of flowering” for most varieties in 2020 and 2023 occurred earlier than the long-term average date by 2-8 days, in 2023 – by 2-6 days, and in 2021-2022 – later by 2-14 days. It was revealed that at the phenophase "beginning of flowering", early cherry varieties (Krasnodarskaya sladkaya, Chudo vishnya), medium (Timati, Feya, Assol’, Svatlaya) are strongly affected by stress. Tamaris and Hodosa cherry varieties of late ripening showed relatively high resistance to stress during the flowering period. Key words: cherry, variety, phenological characteristics, flowering, climate.

Pollen morphology reveals genetic diversity between some superior sour cherry (Prunus cerasus L.) genotypes; an opportunity for expanding breeding possibilities

AbstractPreservation of the genetic diversity of sour cherry in Iran is imperative for the development of improved cultivars tailored to specific ecological conditions. Addressing gaps in research concerning ecological adaptation, resource management and international collaboration related to sour cherry genetic resources in Iran is essential. Bridging these research lacunae can facilitate the implementation of sustainable cultivation practices, optimize production systems and enhance the global utilization of sour cherry genetic diversity. A comprehensive analysis of the morphology and ultrastructure of pollen grains from ten native sour cherry genotypes in Iran was conducted over a two-year period using scanning electron microscopy (SEM). The examination revealed that all pollen grains were unipolar, radially symmetrical and tricolpate. The length and width of pollen grains varied among genotypes, with lengths ranging from 42.17 to 57.57 μm and widths from 20.28 to 28.13 μm. Furthermore, all genotypes exhibited prolate pollen grains, with differing colpus lengths. Examination of pollen exine revealed striate shapes with varying numbers of ridges, ranging from 18.5 to 8.5 furrows per 50 m2. The horizontal area of pollen grains varied from 333.28 to 1491.69 μm. Polar perspective analysis showed considerable variation in the distance between mesocolpium endpoints. Sour cherry displays significant genetic diversity in Iran, and the application of SEM has proven instrumental in characterizing this diversity. This understanding will aid in further breeding research aimed at enhancing sour cherry varieties and their adaptation to specific ecological conditions.

The difference in the photosynthetic characteristics and soil moisture of different varieties of sweet cherry (Prunus avium L.)

Sweet Cherry (Prunus avium L.) is a highly sought-after fruit in the global market due to its nutritional value and appealing sensory characteristics. This paper investigated the indicators of photosynthetic physiological characteristics and changes in soil physical properties of different varieties of sweet cherries grown in the Loess Plateau region, which strengthened the research on the ecological aspects of photosynthetic physiology of sweet cherries. By analyzing the characteristics and similarities of photosynthesis processes in different varieties, the results were obtained to showed that most of these sweet cherries showed obvious inhibition of photosynthesis at noon. The daily net photosynthetic rate (Pn) variation graph displayed a typical bimodal curve, with the lowest values occurring successively at 12:00 pm and 14:00. The Pn of sweet cherry is mainly influenced by water use efficiency (WUE) and transpiration rate (Tr). Rainier and Summit exhibited the best performance in the daily mean of Pn due to the interplay between photosynthetic physiological and ecological factors. To affect the photosynthesis of sweet cherries, covering the greenhouses with plastic film would impact the changes in light intensity and temperature. The crop management mode of uniform mulching and drip irrigation can affect the water content of different soil depths, leading to a reduction in Pn due to the varying WUE and Tr of different varieties of sweet cherries. The order of photosynthetic physiological characteristics of different varieties of sweet cherries, as revealed by principal component analysis, was as follows: Rainier > 4YJimei > 2YTieon > 4YTieon > Summit > Jimei > Tieon > Hongdeng. These results provide a scientific theoretical basis for the introduction, promote the production of sweet cherries and provide a new understanding of the plantation management mode.

Влияние абиотических факторов весенне-летнего периода на формирование хозяйственно ценных признаков у сортов черешни (Сerasus avium L.) в условиях юга России

Abstraсt. This paper shows a variation in the yield of 11 studied sweet cherry varieties from a minimum value of 5 kg/tree in 2020 (Dar izobilya variety) to a maximum of 65.0 kg per tree in 2021 (Kavkazskaya variety), which was more dependent on the weather conditions of the growing season. In this regard, the aim of the research is to study the biological features of the formation of indicators of yield and quality of fruits of Russian and introduced varieties of sweet cherries, and related weather and climatic factors. By means of statistical evaluation, the coefficient of variation was established, which was high for all varieties – from 63.1 % to 97.3 %, which indicates strong fluctuations in yield during the study period (2019-2023). The indicator "fruit weight" is a varietal feature, therefore it does not vary much by year of observation within each variety. Thus, the coefficient of variation in the studied varieties ranged from 2.7 % (Sashenka variety) to 15.8 % (Kavkazskaya variety). By varieties, this indicator varied quite strongly from the lowest value in 2022 of 4.3 g (Kavkazskaya variety) to the highest 10.3 g in 2022 (Krupnoplodnaya variety). According to the results of the study, the varieties that are least affected by climatic factors were identified, which had an average yield of 31.5-35.2 kg per tree over 5 years of study, subject to the almost complete absence of fruits in 2020 these include – Alaya, Volshebnitsa and Dar Isobiliay. A correlation has been established between the studied breeding-valuable indicators and various abiotic factors influencing their formation. The yield index had a high correlation with the average annual air temperature R2 = 0.60 and the amount of precipitation in April – R 2 = 0.60. The fruit weight indicator was most dependent on the average monthly temperature in June, in this case the correlation coefficient was – R 2 = 0.80, as well as the amount of precipitation for the year – R 2 = 0.54. Keywords: variety, sweet cherry, abiotic factors, yield, productivity, fruit weight. Financing source: The research was carried out within the State Task of Ministry of Science and Higher Education of the Russian Federation for the FSBSI NCFSCHVW.

Comparative analysis of biochemical composition of fruits of local selection and introduced cherry varieties grown in conditions of foothill Dagestan

Comparative analysis of biochemical composition of fruits of local selection and introduced cherry varieties grown in conditions of foothill Dagestan

Optimization of clonal micropropagation of stone fruit crops

The aim of the research was to optimize the clonal micropropagation of stone crops through the use of improved techniques. The objects of the research at the stage of introduction into culture in vitro were meristematic apexes, at the stage of micro-propagation itself – micro-shoots, at the rooting stage – rooted micro-shoots, at the adaptation stage – micro-plants. All experiments were carried out according to generally accepted methods using the example of the steppe cherry variety Shchedraya, the domestic plum variety Kazanskaya and the hybrid sweet cherry Fatezh. As a result of the research, it was found that the use of a 10 % chlorhexidine solution for sterilization of the initial plant material of stone crops increased the survival rate of apexes on average by 2.4 %; the combined use of growth regulators 6-benzylaminopurine 0.5 mg/l, gibberellic acid 0.2 mg/l, indo-lil-3-butyric acid (IBA) 0.2 mg/l in a nutrient medium and an experimental diode pulsed phytoirradiator in the last proliferation passage activated the proliferation of micro-shoots, increasing the reproduction coefficient of stone crops in 6 passages by an average of 0.9 pcs/explant; the addition of 1.0 mg/l (IBA ) to the nutrient medium provided an increase in the rooting capacity of micro-shoots of stone crops by an average of 9.6 %. The treatment of micro-plants of stone crops at the stage of adaptation by spraying with an 8 % solution of the extract of the products of the larvae of the large wax moth and the use of an experimental LED pulsed phytoirradiator with a mixed spectrum contributed to an increase in their survival rate by an average of 12.4 %. Compliance with the proposed improved methods of clonal micropropagation of stone crops using growth regulators and an experimental LED pulse phytoirradiator with a mixed spectrum made it possible to increase the yield of standard adapted micro-plants by 2 times. At the same time, the cost of one adapted micro-plant decreased by an average of 11.4 rubles, and the profitability of obtaining improved stone crop material increased by 33.7 % and amounted to 160.7 %.

Tomato quality assessment and enhancement through Fuzzy Logic: A ripe perspective on precision agriculture

This study presents a meticulous exploration of tomato quality assessment and enhancement employing Fuzzy Logic, focusing on beefsteak, Roma, and cherry varieties. The research incorporates a multivariate approach encompassing shape, size, texture, and color analysis. Utilizing a controlled imaging system, 165 tomatoes were captured at various ripening stages to ensure uniformity in lighting, camera position, and background color. Image processing and computer vision techniques, including segmentation and feature extraction, were applied to comprehensively evaluate the tomatoes. Quality assessment involved considerations of three stages of skin coloration, defect quantity, and skin texture calculated using the statistical method of entropy. The decision-making process and quality evaluation were facilitated by a Mamdani-type Fuzzy Inference System, leveraging numerical values of external characteristics such as dimension, calyx shape, ripeness stage, and defect regions. The fuzzy logic-based system employed 22 fuzzy rules and three different membership functions (trapezoidal, Gaussian, and triangular), enabling a nuanced mapping of transitions between classes within the input variables. Furthermore, the system underwent rigorous training and validation using 80% and 20% respectively of the captured images. Through the system, we were able to identify and segment areas of tomatoes exhibiting poor conditions. This approach extends beyond conventional methods of estimating fruit ripeness, which typically rely on color assessment or destructive firmness evaluations.

Molecular characterization and evolutionary relationships of DOFs in four cherry species and functional analysis in sweet cherry

The DOF (DNA binding with one finger) has multiple functions in plants. However, it has received little attention in the research field of cherries. In this study, the evolutionary relationship and molecular characterization of DOF in four cherry species were analyzed, revealing its expression pattern in sweet cherry. There are 23 members in Prunus avium cv. ‘Tieton’, 88 in Prunus cerasus, 53 in Cerasus × yedoensis, and 27 in Cerasus serrulata. Most of these genes are intron-less or non-intron, with a conserved C2-C2 domain. Due to heterozygosity and chromosomal ploidy, whole-genome duplication (WGD) events occur to varying degrees, and DOF genes are contracted during evolution. Furthermore, these genes are affected by purifying selection pressure. Under low-temperature treatment, the expression of PavDOF2 and PavDOF18 were significantly up-regulated, while that of PavDOF16 is significantly down-regulated. The expression of PavDOF9, PavDOF12, PavDOF14, PavDOF16, PavDOF17, PavDOF18, and PavDOF19 exhibits an increasing trend during flower development and varies during sweet cherry fruit development. PavDOF1, PavDOF8, PavDOF9, and PavDOF15 are localized in the nucleus but is not transcriptionally active. The findings systemically demonstrate the molecular characteristics of DOF in different cherry varieties, providing a basis for further research on the functions of these genes.

Enhancing the sustainability of cherry blossom landscapes-a case study in Fujian Province, China

Utilizing flowering cherries to enhance suburban landscapes and attract public recreation holds significant economic and social value. However, the current quality of the cherry landscape is compromised due to the absence of variety selection and planning in planting and design. Based on the analysis of public preference, there is significant importance in boosting the sustainability of cherry blossom landscape. However, related research in this domain still needs to be explored. This study examined four representative cherry blossom landscapes in Fujian Province to assess the landscape quality and growth of existing cherry varieties. Subsequently, an improvement model of cherry blossom landscape quality was developed based on image semantic segmentation, aiming to quantify landscape elements. The findings indicated that: (1) There were a total of 46 cherry varieties blooming from January to March in the four representative cherry blossom landscapes. The health grades distribution was as follow: Grade I accounted for 41.3%, Grade II for 39.1%, Grade III for 8.7%, Grade IV for 6.5%, and Grade V for 4.4%. (2) The highest marginal benefit for flake planting was observed when the flowering ratio exceeded 60% or was less than 15%. In contrast, the optimal flowering ratio for the linear cherry blossom landscape for maximum marginal benefit was over 30.0%. (3) The outcomes of the scenic beauty model revealed that the five major factors influencing the scenic beauty were the scene cleanliness (38.04%), plant color composition (25.59%), road (17.79%), plant type (12.88%) and building (2.70%). The results of this study provide valuable objective data references for the planning, design and management of cherry blossom landscapes.

ВЛИЯНИЕ МИНЕРАЛЬНОГО УДОБРЕНИЯ И ПОДВОЕВ НА РОСТ И РАЗВИТИЕ САЖЕНЦЕВ ВИШНИ СОРТА ТРОИЦКАЯ

The growth and development of fruit crop seedlings depend on various factors that allow increasing the growth and the root collar diameter. The parameters are crucial for obtaining high-quality products. The application of mineral fertilisers allows the plant to fully feed on trace elements throughout the growing season, in conditions when the plant has a limited space for growth but experiences no deficiency in nutrients. Using rootstocks in growing stone fruit trees is critical for the development of seedlings and their resistance to adverse environmental conditions. The variety and rootstock response to mineral fertilisers is another important criterion for obtaining strong cherry seedlings [12, 14]. The Urea mineral fertiliser enhanced the growth of seedlings 1.5-fold on the rootstock of the Ashinskaya and Maak cherry varieties. The fertilisers also increased the root collar diameter: RCD enlarged 1.4-fold on the rootstocks of varieties Ashinskaya and Maaka. The Ashinskaya cherry tree variety has a high regenerative capacity, winter hardiness, rapid growth, high field resistance to pests and diseases [11]. The Maaka cherry tree variety has a monogenic resistance to coccomycosis, high winter hardiness, drought resistance, a high rooting rate of green cuttings and produces no overgrowth. The properties make variety Maaka valuable for rootstock use. The Troitskaya cherry tree variety has an average early ripening period, a high yield, annual fruiting, resistance to pests and diseases, it is a donor of large fruit. The experiment identified the best variant that involved applying the Urea mineral fertiliser at a dose of 5 g / l and, using the Maaka cherry tree variety as a rootstock. The variant demonstrated the highest values for the height of seedlings (68.6 cm) and the highest RCD values (6.9 mm) on average for three years

Study on the control effect of Empedobacte brevis on cherry fruit fly

Abstract: Fruit fly is a major boring pest of cherry fruits during the color change and maturity period. It causes serious damage and affects the quality and economic benefits of cherry fruits. In order to clarify the control effect of Empedobacter brevis on cherry fruit fly and provide basis for guiding scientific medication use. The test adopts the conventional spray method, and uses 60g•L-1 spinetoram suspension as a control to compare and analyze the control effects of different dosages of Empedobacter brevis suspension on cherry fruit fly. The results show that on the three cherry varieties of Red lantern, Tieton and Napoleon, the control effects of Empedobacter brevis 600 times and 800 times and spinetoram 1000 times are better, and the control efficiency reaches more than 78-80%. There is no significant difference in control effects among the three, and they are safe for cherry trees. In cherry production, Empedobacter brevis can be promoted and applied as an effective biological agent to control fruit flies.

A new variety of sour cherry Shelangovskaya

The purpose of the research is the biological and economic evaluation of a new variety of sour cherry Shelangovskaya in the conditions of the Republic of Tatarstan. Winter hardiness, productivity, the susceptibility of sour cherry varieties to coccomycosis, moniliosis, damage by aphids, and economic efficiency were evaluated according to the methodology of the All-Russian Research Institute of Fruit Crop Breeding. A comparative assessment of the biological and economic characteristics of the sour cherry varieties Krasa Tataria and Shelangovskaya showed that the new sour cherry variety surpasses the standard variety in productivity (8 kg), yield (5 t/ha), resistance to coccomycosis (1.9 points), moniliosis (1.5 points), flowering strength (4.6 points), self-fertility (24 %), fruit taste (4.2 points), profit from 1 ha of the garden (26.0 thousand rubles) and the level of profitability (13.1 %).

The behavior of some sour cherry varieties in the southern part of the country

The sour cherry species is of great economic importance due to the quality of the fruits together with the agrobiological particularities of the trees to capitalize on a great diversity of pedoclimatic conditions from the plains to the hills. A major contribution is made by the adaptability of varieties to specific growing conditions. The varieties Vrâncean and Crișana 2 showed very well developed roots at a depth of 40 cm, the roots absorbing soil fertilizers better, an aspect that helps the growth and development of the trees. We found a higher percentage of roots in Mocănești varieties 16 - 24.8%, Schattenmorelle - 22.5% and Vrâncean - 21.8%. The Rival variety stands out with a slightly shallower root system, however, the rooting depth as well as the way of branching is a genetic characteristic. The study of the root system of trees brings great support in solving some theoretical and practical problems.

Study of drought and heat resistance in fruit crop varieties under changing climate conditions (on the example of sweet cherry in Krasnodar Krai)

An important area for improving the effectiveness of agri-food systems under stress conditions is the selection of highly drought- and heat-resistant varieties. The present study aims to develop new approaches to the evaluation of these characteristics, taking into account the ability of varieties to successfully pass through the stages of fruit bud differentiation at high summer temperatures, without their development being suppressed. An analysis of climatic conditions in the Kuban horticultural zone of Krasnodar Krai for 1989–2022 revealed the occurrences of temperatures above +30...+35 C that suppress fruit bud differentiation in fruit crops, thus indicating the need for new data on the stress response of varieties. The variability structure of drought resistance indicators was studied using data for three years (2019, 2021, and 2022): tissue water content and leaf water-holding capacity in sweet cherry varieties grafted on VSL-2, including those bred by an institute (‘Slavyanka’, ‘Kavkazskaya’, ‘Kavkazskaya Uluchshennaya’, ‘Volshebnitsa’, and ‘Alaya’). Their high dependence on seasonal conditions was established. The effect of high temperatures on fruitbud differentiation in cherry varieties was evaluated. The adaptability of plants and varieties to the lack of moisture and high summer temperatures was noted to be inextricably linked. The focus was on a comprehensive approach to evaluating drought and heat resistance in the selection of the best sweet cherry forms that are able to develop normally and set fruitbuds at high temperatures. The latter characteristic should be taken into account when entering varieties into the State Register of Breeding Plantations to establish the possible cultivation limits of the proposed plants and to create new varieties having a higher resistance to temperature stresses. Drought and heat resistant sweet cherry genotypes capable of tolerating summer stresses and regularly yielding crops were identified. The following varieties were found to be resistant to high temperatures: early ripening period – ‘Kavkazskaya’ and ‘Slavyanka’; average ripening period – ‘Volshebnitsa’, ‘Kosmicheskaya’, and ‘Summit’; late ripening period – ‘Alaya’ and low-growing clone of ‘Drogana Zheltaya’.

THE IMPACT OF THE PRUNING TIME ON THE BIOLOGICAL PROPERTIES OF CHERRY VARIETIES GRAFTED ON MAXMA 14

Pruning is a basic procedure in the sweet cherry trees cultivation, which significantly affects the yield and quality of the fruit. The objective of this study was to examine the influence of the pruning time on the biological properties of sweet cherry trees (Prunus avium L.). The orchard in which the research was carried out was established in the central area of the Republic of Moldova in the fall of 2012. The Kordia and Regina sweet cherries, grafted on MaxMa 14, whose crowns had a naturally improved reduced volume, were planted at a distance of 5 x 3 m. The maintenance and fruiting pruning of the sweet cherry trees were done during the dormant and vegetation phases as follows. The flowering and fruit ripening time, the trunk cross-sectional area (TCSA), the number of fruiting buds and the fruit weight and yield were studied. The results showed that the pruning time had had a significant impact on the yield. The data on the yield of the Kordia and Regina sweet cherry varieties grafted on MaxMa 14 are promising and prove that the pruning done in the first decade of September has a positive effect on the fruit yield.

Self-incompatibility of the subgenus <i>Cerasus</i> (Mill.) A.Gray (review)

The selection of pollinators when planting plantings in crop production and parental pairs during hybridization in breeding is closely related to the problem of self-incompatibility. The results of numerous studies show that self-incompatibility is realized through a variety of biological mechanisms and is aimed primarily at preventing inbreeding within a population. Self-incompatibility in many species is determined by one S-locus with many S-alleles. In this case, the S-haplotype combines male and female specificity determinants (S-determinants), and pollen recognition occurs due to a molecular allele-specific interaction between them. In representatives of the genus Prunus, self-incompatibility is controlled by the interaction of genes belonging to the S locus, the combination of variants of which forms a specific S haplotype. Molecular S-genotyping methods are based on S-RNase gene sequences, which allow the identification of S-alleles and the classification of varieties with respect to incompatibility groups. To date, 31 S-haplotypes have been identified in sour cherries and sweet cherries, and some of the haplotypes are identical to each other. In sour cherry, 12 functional S-haplotypes and 9 nonfunctional ones have been described. 6 S-haplotypes of sour cherry species have also been described. Mutations that occur not only in the S-RNase and SFB genes, but also in regions not associated with the S-locus can lead to disruption of the self-incompatibility mechanism. Studies on the identification of self-incompatibility alleles of representatives of the Cerasus subgenus were in many cases carried out on the species P. avium L. The formation of self-(in)compatibility of tetraploid genotypes of sour cherry is due to the presence of mutations in the S-locus genes, which lead to the appearance of non-functional S-haplotypes. Self-incompatibility of pollen in sour cherry occurs when one fully functional S-allele in the pollen corresponds to one functional S-haplotype in the pistil. Currently, the study of the mechanism of self-incompatibility continues, and genotyping of sour cherry and sweet cherry varieties is carried out at S-loci. DNA analysis data is promising for predicting the level of compatibility of varieties during pollination and fruit set during hybridization.

Development and validation of phenological models for eight varieties of sweet cherry (Prunus avium L.) growing under Mediterranean climate condition

The projected increase in temperatures caused by climate change will modify the phenological stages of sweet cherry in Mediterranean-type climate regions. This study aimed to develop and validate phenology models for eight sweet cherry varieties (Sam, Lapins, Rainier, Royal D, Santina, Regina, Kordia, Sweet Heart) in the Maule Region, Chile. The models were based on growing degree days (GDD), and the stochastic monomolecular model was employed to account for the randomness caused by measurement errors affecting the prediction of phenological states. A dataset of phenological stages was compiled over four growing seasons: 2017-2018, 2018-2019, 2019-2020, and 2020-2021. The results revealed a significant correlation (with R2 values between 0.96 and 0.98) the modified phenological (PS) scale of Biologische Bundesanstalt, Bundessortenamt, and Chemical Industry (BBCH) and GDD for all eight varieties. The validation of the model demonstrated root mean square error (RMSE), mean absolute error (MAE), and model efficiency (FE) values ranging from 1 to 1.3, 0.79 to 1.1, and 0.82 to 0.92, respectively. Finally, monomolecular model estimated the modified scale of BBCH with errors less than 2 %.

Embryo rescue in stone fruit breeding: specifics and application success

The development of stone fruit varieties that meet modern production requirements is a labor-intensive process involving low yields of progeny obtained through controlled intraspecific and interspecific hybridization, which can take up to 25 years. The non-viability of hybrid seeds is caused by the abortion of the embryo that does not have time to complete its morphophysiological development and endosperm abortion in interspecific hybrids. It is possible to preserve hybrids having a unique combination of traits by removing embryos derived from interspecific and intergeneric crossing that are unable to survive in vivo or when using conventional methods for breeding embryos at early developmental stages and placing them under in vitro conditions for further development. On the basis of literary sources, the study aims to analyze growth media, conditions of their application, and time of embryo placement under in vitro conditions designed to preserve immature embryos and create hybrids of stone fruit crops, as well as to identify the most effective in vitro embryo isolation schemes for further use in the breeding process. The analytical review used open sources containing information on the composition of the most commonly used growth media, their compositions, modifications, application conditions, time of embryo placement under in vitro conditions for common peach (Prunus persica (L.) Batsch.), common apricot (P. armeniaca L.), common plum (P. domestica L.), Chinese plum (P. salicina Lindl.), cherry plum (P. cerasifera Ehrh.), sloe (P. spinosa L.), sour cherry (P. cerasus L.), sweet cherry (P. avium (L.) L.), as well as electronic scientific libraries (eLibrary, Scopus, and Google Scholar). The performed analysis of works revealed the following media as optimal for sustaining the development of embryos: common peach – modified growth medium Woody Plant (up to 100 % of preserved embryos); common apricot – modified Monnier (up to 92.4 % of preserved embryos); sour cherry, sweet cherry, plum, and interspecific hybrids – different variants of Murashige and Skoog (over 70 % of preserved embryos). The used modifiers include 6-benzylaminopurine (6-BAP), gibberellic acid (GA), kinetin, peracetic acid, carbohydrates, L-glutamine, iron chelate, ascorbic acid, thiamine, glutamic acid, tryptophan, casein hydrolysate, etc. The time of placement under in vitro conditions varies from 28 days (sour cherry) to 99 days (common peach) depending on the crop. Stratification in the dark at +4…+5 ℃ prior to development increases the yield of viable embryos. The optimal photoperiod for in vitro embryo cultivation ranges from 12 (common peach) to 16 (cherry plum, sour cherry, sweet cherry, and interspecific hybrids) hours. As a result of selection from the fund of hybrids obtained through embryo preservation, one common peach variety (Krymskii Shedevr) and three sweet cherry varieties (Vesnyany Naspivy, Prizerka, and Uslada), recommended for the North Caucasus region, were included in the State Register of Breeding Achievements approved for use; two common plum varieties (Tulitsa and Velichavaya) were included into the Register of Protected Breeding Achievements for the Central Region.

Phenological aspects of the development of sweet cherry varieties in the environmental conditions of the Right-Bank Forest-Steppe of Ukraine

The article presents the results of the study of the seasonal rhythm of the growth and development processes of sweet cherry varieties in the conditions of the Right-Bank Forest Steppe of Ukraine. The beginning of culture development, passage and duration of the main phenophases are determined. There is slight varietal variability between the dates of the beginning and duration of vegetation in accordance with changes in weather conditions. As a result of the conducted observations, it was established that the beginning of vegetation of sweet cherry varieties takes place in the first decade of April. The beginning of flowering of cherry trees is noted in the first half of the third decade of April, the variation of cherry blossoming beginning over the years reaches 5–10 days, which is most typical for the example of the «Dar Mlieva» and «Drogan yellow» varieties. The onset of harvestable ripeness largely determines the variety's belonging to the ripeness group. The fruits of the «Mliivska yellow», «Dar Mlieva», and «Zoryana» varieties are the first to be harvested, and after 26 days, the fruits of the «Amazon» variety are harvested. According to the results of observations, sweet cherry varieties were conditionally divided into groups of ripeness: early ripening, in which the fruits ripen 44-48 days after flowering, medium ripening – fruits ripen 50–60 days after the end of flowering, late ripening – fruits ripen later than 60 days after flowering. Depending on the onset of the harvestable ripeness of the fruits and the duration of the fruiting phase, for timeliness and convenience of harvesting it became possible to create a kind of harvesting conveyor. The duration of the growing season was on average 186 days in the early-ripening group of sweet cherry varieties with the shortest period in the «Mliivska yellow» variety, 191 days for the medium-ripening group varieties with the longest period in the «Melitopolska krapchasta» variety and the shortest in the «Alyonushka» variety, in the lateripening varieties «Biruza» and «Amazon» varieties 196 and 200 days respectively. Key words: sweet cherry varieties, phenological phases, vegetation period, vegetative organs, duration of the growing season.