Vegetative Buds Research Articles

Winter hardiness of promising pear varieties in the conditions of the steppe zone of the Southern Urals

The article presents the results of a long-term study of the winter hardiness of pear varieties of domestic breeding in the conditions of the steppe zone of the Southern Urals (Orenburg region). The research was carried out in the Orenburg branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery in 2018-2021 at the experimental site of the genetic collection of pears in 2002 planting according to generally accepted methods. Mathematical processing of the obtained data was performed using variance analysis by Dospekhov B. A. (2011). Field assessment of winter hardiness was carried out in the I-II decades of May after flowering and budding of vegetative buds. Damage to the bark, kidneys and wood was assessed by eye on a scale: 0 points − no damage, 5 points − tissues died. The objects of research were 15 varieties of pears. Planting scheme: 6×4 m. It was found that during the years of research in the conditions of Orenburg, the most unfavorable weather conditions were observed in the winter of 2017-2018 and 2020-2021, which made it possible to study the hardiness of varieties in the field by II-IV components. It was found that the studied pear varieties have sufficient winter hardiness, the degree of damage to them was: wood − 0,5-1,5 points, bark − 0,5-1,8 points and kidneys − 0,8-1,8 points. At the same time, the plants quickly recovered and began to actively vegetate, which indicates the high adaptive ability of most varieties. The greatest resistance to adverse winter conditions at the level of the control winter-hardy variety Krasnobokaya was shown by the varieties Krasulya, Skazochnaya, Pingvin, Isetskaya Sochnaya, Lel, Chizhovskaya, Lada, Uralochka and Povislaya, which can be recommended for use in the breeding process as sources of a sign of high winter hardiness.

Allometry of bud dynamic pattern and linkage between bud traits and ecological stoichiometry of Nitraria tangutorum under fertilizer addition.

Affected by the pressure and constraints of available resources, plant growth and development, as well as plant life history strategies, usually vary with environmental conditions. Plant buds play a crucial role in the life history of woody plants. Nitraria tangutorum is a common dominant woody species in desertified areas of northern China and its growth is critical to the desert ecosystem. Revealing the allometry of N. tangutorum aboveground bud fates and the linkage between bud traits and plant nutrient contents and stoichiometric ratios can be useful in understanding plant adaptation strategy. We applied seven nitrogen and phosphorus fertilizer addition treatments to natural N. tangutorum ramets in Ulan Buh Desert in three consecutive years. We surveyed three types of aboveground buds (dormant buds, vegetative buds, and reproductive buds) in each N. tangutorum ramet, then measured the plant carbon (C), nitrogen (N), and phosphorus (P) contents and ratios during three consecutive years. We specified that reserve growth potential (RGP), vegetative growth intensity (VGI) and sexual reproduction effort (SRE) are the three indices of bud dynamic pattern. The results showed that the bud dynamic pattern of N. tangutorum ramets differed significantly among different fertilizer addition treatments and sampling years. The allometry of RGP, VGI, and SRE was obvious, showing size dependence. The allometric growth relationship fluctuated among the sampling years. The linkage between bud traits and plant stoichiometric characteristics of N. tangutorum ramets showed close correlation with plant P content, C:P and N:P ratios, no significant correlation with plant C content, N content and C:N ratio. These results contribute to an improved understanding of the adaptive strategies of woody plants growing in desert ecosystems and provide insights for adoption of effective measures to restore and conserve plant communities in arid and semi-arid regions.

Evaluation of selected promising land races of small cardamom (Elettaria cardamomum (L.) Maton) in South India

Small cardamom (Elettaria cardamomum (L.) Maton.), often referred to as the 'queen of spices' is believed to have originated in the moist evergreen forests of the Western Ghats of South India. The present study was conducted at the Indian Cardamom Research Institute, Myladumpara, Idukki Dt. of Kerala. Different farmer's varieties, nine landraces viz., Njallani Green Gold, Thiruthali, Panikulangara Green Bold No.1, Wonder Cardamom, Elarajan, Arjun, Pappalu, PNS Vaigai, Pachaikkai and ICRI-5 as control were evaluated in the cardamom tract of Idukki District. The selected genotypes were evaluated in the field for three consecutive years. The data on growth and yield were recorded, pooled and analyzed. From the analysis, it was found that the genotype Njallani Green Gold performed well compared to other varieties with respect to the yield (1271.80 kg/ha) followed by Panikulangara Green Bold No.1 (1134.67 kg/ha) and more tillers (74.46) were found in the same clone also. The plant height was significantly higher in Elarajan (316.24 cm), followed by Panikulangara Green Bold No.1 (312.45 cm). The number of leaves was greater in Elarajan (16.72), followed by Panikulangara Green Bold No.1 (16.43). More vegetative buds were observed in Pappalu followed by Wonder Cardamom. Panicles per clump were more in Thiruthali (47.98), followed by Njallani Green Gold (46.59). Racemes per panicle were greater in Pachaikkai (26.57), followed by Njallani Green Gold (26.19). The number of capsules per racemes was more in Njallani Green Gold (9.59) followed by Panikulangara Green Bold No.1 (8.59). The results pointed out that each clone in the trial differs from another with respect to the characters studied. The findings could be used for further breeding studies in small cardamom.

Proteomic landscape presents cues for vegetative to reproductive transition in mango

Proteome-based vegetative and flower bud formation characterization was utilized to identify and differentiate protein species with significant variable abundance during floral transition in mango cv. Dashehari using 2DE and corroborated the identified protein spots using gene expression analysis. Total soluble proteins were phenol-extracted from mango cv's vegetative and floral flush. Dashehari and separated on 2D gels at pH 4-7. The protein spots with variable intensity were identified through SameSpots software. The protein sequences of differentially accumulated spots were identified based on PI and MW using Citrus sinensis proteome isoelectric focusing database. Furthermore, these protein sequences were used to conduct (tBLASTn) against Mangifera indica to predict the protein. Real time gene expression was done to corroborate identified proteins. Total 301 spots were detected, out of which 16 were identified as differentially expressed (P?0.05) and a 2-fold change. These 16 protein spots were identified on the basis of in silico comparative mapping protein against genome of mango and citrus, a close relative. They were classified into eight categories: transcriptional regulation, phenylpropanoid pathway and cell wall /cytoskeleton metabolism-related proteins, hormone signalling, flowering time, signal-transduction, transport and protein synthesis to flowering. Five genes coding for shortlisted proteins were used for validation of results using gene expression analysis. SAM (S adenosyl methonine synthase) was found up-regulated in floral flush, involved in the biosynthesis of polyamines has association with flowering, and stress responses. Furthermore, ARF (Auxin Response Factor), serine/threonine kinase gene members were also found to play critical role in determining floral development process in mango, consistent with results obtained through 2DE. Protein species that are putatively involved in phenylpropanoid pathway were also identified, showing the process of mango flowering from a new perspective beyond the conventional view. This flowering related proteomics study provides an overview of the biological pathways and regulatory mechanisms associated with flowering developmental physiology.

Mango malformation: etiology, symptoms, distribution and cultivar susceptibility in the Dominican Republic

Mango malformation disease (MMD) caused by Fusarium species has become an important disease of mango ( Mangifera indica L.) orchards worldwide. In the Dominican Republic, MMD was first observed in 2008 in orchards of Azua and Peravia provinces, with incidence of up to 50%. This study aimed to estimate the malformation prevalence and distribution in the main mango growing areas of the Dominican Republic and to assess the susceptibility of six commercial cultivars commonly grown in this country. Mango malformation was found in 18 out of 58 orchards, all located in Peravia and Azua. Peravia showed the highest incidence, with values of up to 75% (2013) and 87.5% (2014), and the interpolative analysis made with ArcGIS showed this province as being more inductive for Fusarium spp. occurrence. Pathogenicity tests were conducted in 2013 and 2014 on 10-month-old healthy mango plants per cultivar. Inoculation was done by infiltration of Fusarium pseudocircinatum and Fusarium decemcellulare conidial suspensions into the vegetative apical buds, singly and in combination. In inoculated plants, symptoms such as loss of apical dominance, excessive proliferation of apical or axillary buds with thickened stems, and reduction of leaf lamina were associated with F. pseudocircinatum. In addition to these symptoms, leathery protuberant buds and eventual death of infiltrated plants were associated with F. decemcellulare, singly or coinoculated with F. pseudocircinatum. Based on a disease severity index (DSI), “Tommy Atkins” was tolerant (DSI = 7.8%) and “Puntica” and “Banilejo” were highly susceptible (DSI = 22% and 28.5%).

Relationship between the Growth of Current Shoot and the Development of Inflorescence and Vegetative Buds in Oncidesa Gower Ramsey ‘Honey Angel’ Leaf Axils

The flowering control of Oncidesa Gower Ramsey ‘Honey Angel’ is important and in-demand by the industry. Therefore, an understanding of the development of inflorescence and vegetative shoot from the leaf axils on the current shoot is required. The internode of a young Oncidesa current shoot between the 0th (at the base of the pseudobulb) and 1st (immediately above the pseudobulb) nodes can enlarge to form a pseudobulb, and the axillary bud on the 0th or -1st (immediately below the 0th node) node can differentiate into an inflorescence bud. The axillary buds on the lower nodes (-2nd to -4th nodes) can remain vegetative. In this study, we investigated the growth and anatomical features of axillary buds at various stages during the growth of the current shoot. We sampled the axillary buds on the 0th to -4th nodes from the current shoots when they were 10, 15, 20, 25, and 30 cm in length for sectioning and anatomical observations. Vegetative buds on the -2nd to -4th nodes grew faster and had more nodes than the inflorescence bud when the current shoot grew from 10 to 25 cm. However, when the current shoot elongated from 25 to 30 cm, the length and node number in the inflorescence bud on the 0th node increased and the inflorescence branch primordia were observable. The length and node number of the inflorescence bud became the same as that of the vegetative buds, which had no further growth, whereas the current shoot grew from 25 to 30 cm. The pseudobulb began to emerge from the leaf sheath (unsheathing) when the current shoot had reached 30 cm in length. Therefore, the time when the pseudobulb started to unsheathe from its subtending leaf was critical for the reproductive growth of Oncidesa Gower Ramsey ‘Honey Angel’ when growth acceleration of the inflorescence bud occurred. Evaluating the current shoot length can be a nondestructive method of estimating the developmental stage of the inflorescence bud.

In the Beginning Was the Bud: Phytochemicals from Olive (Olea europaea L.) Vegetative Buds and Their Biological Properties.

Even though Olea europaea L. is one of the most important and well-studied crops in the world, embryonic parts of the plants remain largely understudied. In this study, comprehensive phytochemical profiling of olive vegetative buds of two Croatian cultivars, Lastovka and Oblica, was performed with an analysis of essential oils and methanol extracts as well as biological activities (antioxidant, antimicrobial, and cytotoxic activities). A total of 113 different volatiles were identified in essential oils with hydrocarbons accounting for up to 60.30% and (Z)-3-heptadecene being the most abundant compound. Oleacein, oleuropein, and 3-hydroxytyrosol had the highest concentrations of all phenolics in the bud extracts. Other major compounds belong to the chemical classes of sugars, fatty acids, and triterpenoid acids. Antioxidant, antimicrobial, and cytotoxic activities were determined for both cultivars. Apart from antioxidant activity, essential oils had a weak overall biological effect. The extract from cultivar Lastovka showed much better antioxidant activity than both isolates with both methods (with an oxygen radical absorbance capacity value of 1835.42 μM TE/g and DPPH IC50 of 0.274 mg/mL), as well as antimicrobial activity with the best results against Listeria monocytogenes. The human breast adenocarcinoma MDA-MB-231 cell line showed the best response for cultivar Lastovka bud extract (IC50 = 150 μg/mL) among three human cancer cell lines tested. These results demonstrate great chemical and biological potential that is hidden in olive buds and the need to increase research in the area of embryonic parts of plants.

Genome-wide Transcriptome Analysis Reveals the Gene Regulatory Network in Star Fruit Flower Blooming

The star fruit is a perennial woody fruit tree, which can blossom and bear fruit many times a year. The time and quantity of flowering are the key indicators of its economic value. However, the flowering molecular mechanism of star fruit is still unknown. This study provides a genome-wide analysis of the key flowering genes of star fruit. Based on a previous morphological study of flower bud differentiation, the reproductive buds, vegetative buds and mature leaves of star fruit were sampled for transcriptome analysis. The results showed that the expression of GI, COL4, COL5, FT, FCA, FVE, PIF4, LFY, SVP-like, AP1 and FUL was correlated with floral induction and transition. The expression of TFL1, SVP-like genes (Yangtao2015203 and Yangtao2021074) was correlated with the inhibition of floral transition. Thus, we proposed a putative network of flower blooming in star fruit. This study provides useful information for investigating the genetic mechanism of flowering in star fruit and other perennial woody fruit trees.

Plant sex changes the outcome of ant–plant interactions in a facultative myrmecophytic cactus

Abstract In exchange for extrafloral nectar, ants deter herbivores from the plants decreasing the herbivore damage, and increasing plant performance in terms of growth and survival. Plants of different sexes may exhibit differences in the investment of resources for defence, thereby differentially decreasing the amount of energy available to other physiological processes. In this context, little is known about sex‐related differences in the outcome of ant–plant interactions in plants bearing extrafloral nectaries (EFNs). In the present study, we conducted ant‐exclusion experiments in the field to test for sex‐related differences in the outcome of ant–plant interactions in vegetative and reproductive buds of Opuntia robusta in individuals of different sexes in two populations: trioecious and dioecious. We applied tanglefoot to some plant and others were allowed ant access, and measured herbivory, relative growth rates and survival probabilities of buds during the growing season when EFNs are active. We counted the number of ants foraging in EFNs of flowers and cladodes of different sexes. We hypothesized that differences in resource investment to defence between sexes change the outcome of ant–plant interactions in terms of the number of ants foraging on EFNs, herbivory, growth, and survival probabilities. Our results suggest sex‐specific strategies in the investment of resources for defence mediated by EFNs in O. robusta, wherein males, females and hermaphrodites from both populations respond differentially to ant presence and herbivores. These sex‐related differences affected the outcome of the ant–plant interactions, influencing changes in number of ants foraging on EFNs, and the resulting herbivory, growth and survival of flowers and cladodes among the different sexes and among populations. Our results suggest that the maintenance of EFNs in O. robusta is costly, reflecting some trade‐offs between growth/survival and defence. Buds visited by ants tended to grow slowly and survive worse in the trioecious population; in the dioecious population they grew slower but survived better. Overall, a greater number of ants visiting EFNs was related to lower herbivore damage, greater growth and survival of flowers and cladodes. Our study underscores the importance of considering plant sex in the outcome of ant–plant interactions. Read the free Plain Language Summary for this article on the Journal blog.

Subterranean Clover and Sulla as Valuable and Complementary Sources of Bioactive Compounds for Rainfed Mediterranean Farming Systems.

Mediterranean pasture and forage legumes are important components of sustainable production systems. Subterranean clover and sulla represent key species having proven high agronomic value and traits for production and multiple services. Our research investigated the potential of the abovementioned species as a source of phenolic compounds and antioxidants for contributing to support their full exploitation in the fodder, animal welfare, and nutraceutical sectors. Antioxidant capacity, as well as the content of total phenolic compounds and individual phenolic compounds, was determined in subterranean clover and sulla shoots at the vegetative, flower bud, flowering, and seed ripening phenological stages. The antioxidant capacity and the phenolic content were affected significantly by harvest time. In subterranean clover, 10 individual phenolic compounds were detected, and isoflavones were the most abundant (3.19-18.27 mg·g-1 DM). Eleven phenolic compounds were identified in sulla shoots, and chlorogenic acid (0.76-3.43 mg·g-1 DM) and diosmin (3.64-4.94 mg·g-1 DM) were the most represented compounds at the vegetative and flower bud stage. On the basis of our findings, a complementary utilization of both legume species is suggested; this might ensure the exploitation of all phenolic compounds in view of the potential benefits for animal production and health.

Predicting flower induction of litchi (Litchi chinensis Sonn.) with machine learning techniques

The flower induction is a critical physiological change during which vegetative buds transit to floral buds. The duration of flower induction (DFI) for litchi plays determinative role for the success and the quality of flowering. It is hard to be reliably predicted because multiple factors including ages of trees, variety and dynamically environmental and climate variables have important impacts. Here we predicted the DFI for four litchi varieties using random forest (RF) implicit and stepwise regression (STR) explicit machine learning models. These models were trained and validated from the data consisting phenological phases from the mature of the last autumn shoots to the flower shedding, and the corresponding meteorological factors from 2009 to 2020. The DFI predictive models consider timescales from 1 h up to 10 days, and the determination coefficients from the 5-fold cross validation achieves 0.96 to 0.99. The high accuracy was maintained in the blind test, with the determination coefficients of 0.97–0.98 for the data in 2019 and 0.78–0.88 for 2020. The reliability is still sufficient to guide the cultivation of litchi although the dramatic climate change weaken the inherent multiple correlations for DFI. From these robust predictive models, we found ten important features that can be used to determine the DFI with consistent positive or negative contributions. They are the minimum cooling rate, the maturity time of the last autumn shoot, the maximum heating rate, the mean of minimum temperature, the mean of maximum temperature, the amount of heat accumulation at hot day with the minimum daily temperature above 22 °C, the maximum daily temperature below 26 °C, the minimum daily temperature below 6 °C, age, and the atmospheric relative humidity.

Plant height determines phenological variation in Quercus suber L.

Phenological traits of vegetative apical buds were monitored in a Quercus suber L. (cork oak) montado near Lisbon during 2015. Natural regeneration plants, growing at a fenced plot, and mature trees (MT) from the surrounding montado were selected and divided in six groups (n=8) according to height (H): Sd1 (small seedlings, H<0.1 m); Sd2 (seedlings, 0.1<H<0.5 m); Sp (saplings, 1<H<2 m); Jv1 (small juveniles, 3<H<6 m); Jv2 (juveniles, H>6 m); MT (mature trees). Observations included budburst date, apical shoot elongation and leaf production. Vegetative phenology patterns of Q. suber changed according to height/age group. Average budburst dates occurred between early-April (day 99, Sd1) and mid-May (after day 120, mature and juvenile trees), at day lengths between 12.8 (Sd1) and 13.7 hours (Jv2). Height was positively related with average budburst dates, degree day sums and daylength at budburst. Shoot elongation followed different patterns according to size/age group. In seedlings, cumulative growth was smaller and restricted to the weeks immediately after budburst, whilst taller/older trees phenological patterns were more variable, with vegetative growth often maintained until mid-summer. The differences in budburst timing and vegetative growth patterns may be reflecting the different strategies to cope with resource limitation and maximize the length of the growing season among groups.

Cytogenetic and Biochemical Characteristics of Callus <i>Pinus sylvestris</i> L.

A comprehensive assessment was carried out of the changes occurring during the darkening of the callus obtained from vegetative buds of 40-year-old Scots pine treesPinus sylvestrisL. Based on biometric assessment of callus (intensity of callus formation, proportion of light callus, callus mass) from 32 analyzed trees (16 genotypes represented by two clones), two genotypes with high callus-forming ability were singled out. Analysis of mitosis showed that, although the proportion of aberrant cells in the callus does not exceed the rate of spontaneous mutation forP. sylvestris, the range of violations at the stage of meta-, ana-, and telophase in the callus culture was wider compared to that in the seed progeny of the same pine trees. Darkening of the callus was accompanied by a decrease in sucrose metabolism in the cell (decrease in cytoplasmic, vacuolar invertase and sucrose synthase) and a significant decrease in peroxidase activity. At the same time, the activity of apoplast invertase was maintained at a constant level. The activity of superoxide dismutase, catalase, polyphenol oxidase, and phenylalanine ammonia lyase, on the contrary, was higher in dark callus. The possible use of the studied enzymes as biochemical markers of the transition to darkening callus pine crops is discussed.

Histological Studies in Vegetative and Reproductive Mango Buds

The present study was conducted on ten mango cultivars namely Alphonso, Bangalora, Kalepad, Himayuddin, Sendura, Mulgoa, Neelum, Rumani, Banganapalli and Swarnarekha and seasons are main and off-season at Kanyakumari and Tenkasi. The stem along with bud sample was collected during the month of October and November and conducted to examine the relation between internal structure of leafy and reproductive bud. During main season. Among ten mango cultivars, Bangalora and Swarnarekha have well developed at kanyakumar during main season for stage I, whereas Tenkasi, Alphonso and Bangalora well developed buds during the main season in stage I was observed. During off-season observed at kanyakumari Neelum and Alphonso had well developed for vegetative bud in stage I. At Tenkasi cultivars Kalapad and Bangalora had well developed for vegetative bud in stage I. The climatic factors prevailing at Kanyakumari during the main and off seasons for the months of August to September low temperature (190C to 210C) and high humidity (85 to 90%) and main season for the month of October to November, low temperature (210C to 230C) and humidity (80 to 85%). Whereas reproductive stage observed mango cultivars, Alphonso, Bangalora, Kalapad, Neelum and Swarnarekha had well developed reproductive buds in stage II & III during main season at kanyakumari. During off-season, cultivars of Himampasand, Kalapad, Alphoso, Neelum and Swarnarekha had well developed reproductive bud for stag II & III was favoured different stages of bud differentiation in the ten cultivars of mango.

Monilinia fructigena Suppressing and Plant Growth Promoting Endophytic Pseudomonas spp. Bacteria Isolated from Plum.

Brown rot caused by Monilinia spp. fungi causes substantial losses in stone and pome fruit production. Reports suggest that up to 90% of the harvest could be lost. This constitutes an important worldwide issue in the food chain that cannot be solved by the use of chemical fungicides alone. Biocontrol agents (BCAs) based on microorganisms are considered a potential alternative to chemical fungicides. We hypothesized that endophytic bacteria from Prunus domestica could exhibit antagonistic properties towards Monilinia fructigena, one of the main causative agents of brown rot. Among the bacteria isolated from vegetative buds, eight isolates showed antagonistic activity against M. fructigena, including three Pseudomonas spp. isolates that demonstrated 34% to 90% inhibition of the pathogen's growth when cultivated on two different media in vitro. As the stimulation of plant growth could contribute to the disease-suppressing activity of the potential BCAs, plant growth promoting traits (PGPTs) were assessed for bacterial isolates with M. fructigena-suppressing activity. While all isolates were capable of producing siderophores and indole-3-acetic acid (IAA), fixating nitrogen, mineralizing organic phosphate, and solubilizing inorganic phosphate and potassium, only the Pseudomonas spp. isolates showed 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Overall, our study paves the way for the development of an eco-friendly strategy for managing M. fructigena pathogens by using BCAs including Pseudomonas spp. bacteria, which could also serve as growth stimulators.

Phenological growth stages of Magnolia ×soulangeana according to the extended BBCH scale

AbstractMagnolia × soulangeana, one of the most famous ornamental trees of Magnoliaceae, is widely cultivated around the world. However, its phenological characteristics at life‐cycle scale have never been detailedly reported so far. In this article, the extended BBCH (Biologische Bundesanstalt, Bundessortenamt, und Chemische Industrie) scale was applied to divide the growth and development cycle of M. × soulangeana in both juvenile phase and adult phase, and describe the characteristics of phenological development stage, so as to provide theoretical guidance for its cultivation measures implementation. Based on the BBCH phenological scale, the processes of germination (0), leaf development (1), main stem elongation (3) and dormancy (9) were observed in the juvenile phase. Likewise, the morphological changes of organs in adult phase were abundant, and eight principal growth stages were described: vegetative bud development (0), leaf development (1), shoot development (3), reproductive development (5), flowering (6), fruit development (7), maturity of fruit (8) and dormancy (9). Our newly developed scale provides a unified standard for describing and identifying the phenological period of M. × soulangeana. In addition, it is of great significance to understand the phenological characteristics of M. × soulangeana for its breeding and cultivation management.

Contents of nitrogen compounds during bud break and peach tree performance in response to budburst-inducing products

The growth of peach orchards in subtropical regions depends on the minimal requirements for chilling accumulation, and crop loading requires sprays of chemical compounds to overcome dormancy, induce bud break, and allow adequate flowering and fruiting. The ability of hydrogen cyanamide, nitrogen fertilizer and calcium nitrate to break the dormancy of ‘BRS Kampai’ peach trees and their effects on nitrogen, tryptophan, and polyamine contents in buds were evaluated. Furthermore, budburst, flowering, fruit set percentage, flowering period, tree performance, and bioactive compound content in the fruits were assessed. The study was undertaken in São Paulo state, a subtropical region of southeast Brazil, and the field experiment was carried out in two crop seasons. Short flowering duration and higher percentages of budburst, flowering, and fruit setting were correlated with higher nitrogen content in vegetative buds and spermidine contents in flower buds. The better performance of hydrogen cynamide, compared with other treatments, was confirmed by the anticipation, patterning, and increase in budburst, flowering, and fruit setting, associated with high levels of spermidine in the flower buds. Hydrogen cyanamide also increases the concentration of antioxidant compounds in fruits. Hydrogen cyanamide and the combination of nitrogen fertilizer and calcium nitrate enhanced yield and production efficiency and are recommended for inducing budburst in subtropical regions.

Genome-wide identification, characterization and expression analysis of the ABA receptor PYL gene family in response to ABA, photoperiod, and chilling in vegetative buds of Liriodendron chinense

Abscisic acid (ABA) is a signaling phytohormone in plants to improve stress adaption under harsh environments. ABA is sensed by the pyrabactin resistance1/PYR1-like/regulatory components of the ABA receptor (PYR1/PYL/RCAR) (named PYLs) and is the core regulator of ABA stress signaling. ABA receptor PYL gene family have been well studied in rubber tree, apple, Theobroma cacao, Ricinus communis, and Vitis vinifera. We first revealed the genome-wide comprehensive analysis to classify the PYL genes in the L. chinense. This study highlighted the seven LchiPYL genes in the L. chinense genome. The detailed investigations about gene structure variations, chromosomal distributions, phylogenetic tree, 3D structure, motif analysis, cis-regulatory elements, subcellular location, and expression profiles in buds and stress responses were carried out in this article. Phylogenetic tree analysis exploited that the seven LchiPYL genes were divided into four groups (Group I–IV) from L. chinense, and three were highly linked with other species. By analyzing the cis-elements in the promoters, we identified five hormones-, six stress-, three growth and biological process, and two metabolic-related responsive elements. The expression analysis showed that all seven genes were up-and down-regulated against response to ABA, photoperiod, chilling, and chilling + photoperiod treatments. Our findings opened up new future research directions and provided insight into the PYL family genes in Liriodendron chinense.

Evidence of chromatin and transcriptional dynamics for cold development in peach flower bud.

In temperate zones, fruit trees regulate their annual growth cycle to seasonal environmental changes. During the cold season, growth is limited by both environmental and genetic factors. After the exposure to low temperature and fulfillment of chilling requirements, mild temperatures promote the growth and flowering. However, an insufficient chilling exposure may lead to nonuniform blooming, with a negative impact on fruit set. To gain insights into flower development in the fruit tree buds, peach is an interesting model, the flower and vegetative bud being distinct organs. To understand how flower bud development is regulated, we integrated cytological observations and epigenetic and chromatin genome-wide data with transcriptional changes to identify the main regulatory factors involved in flower development during chilling accumulation. We demonstrated that growth cessation does not occur in peach flower buds during chilling accumulation, but that there are changes in transcript abundance of key genes of hormone metabolism and flower bud development, distribution of histone modifications (H3K4me3 and H3K27me3) and DNA methylation. Altogether, our findings indicate that during the cold season the flower bud is in a nondormant state and that the chilling experience allows flower differentiation to be completed.

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.