Vegetative Buds Research Articles

Vegetative and reproductive morphology of Othniophyton elongatum (MacGinitie) gen. et comb. nov., an extinct angiosperm of possible caryophyllalean affinity from the Eocene of Colorado and Utah, USA.

Eocene foliage formerly attributed to the extant araliaceous genus Oreopanax was found attached to twigs bearing inflorescences and infructescences unlike those of Araliaceae. Using newly observable characters of phyllotaxy, vegetative and floral buds, infructescences and seeds, we sought to reassess the affinities of this strange angiosperm. Fossils were studied from the Parachute Creek Member of the Green River Formation from near Bonanza, Utah and Douglas Pass, Colorado (ca. 47 Ma). Macrofossil impression remains were investigated by low angle reflected light and subtle details of the vegetative and floral buds, stamens, mature fruits, and seeds were revealed by optical shadow effect microscopy documenting previously obscure topographic surface features. Othniophyton elongatum (MacGinitie) Manchester, Judd, Correa-Narvaez gen. et comb. nov. has simple, short-petiolate, elongate, entire-margined leaves with thick midveins, pinnate, brochidodromous secondaries, common intersecondary veins and finely reticulate higher order venation. Inflorescences are small axillary cymes; flower buds are subglobose and pedicellate, in bract axils. The flowers are actinomorphic, bisexual, with ca. five imbricate perianth parts, ca. 24 stamens with elongate anthers and short filaments, arising from a hypanthium. The whorl of stamens persists to fruiting stage. The ovary is superior, with probable basal placentation and five stigmatic arms. Fruits are pedicellate berries with a cup-shaped hypanthium and contain ca. 15 lensoidal reniform seeds, each with a curved embryo and ornamented with concentric ridges. The combined characters refute the prior placement in Araliaceae, and rule out affinities with most extant clades of angiosperms. The distinctive combination of observed features does not coincide with any extant family. Among extant orders of Eudicots, the fossil seems to conform most closely to the order Caryophyllales, but key differences remain. This example indicates that the vegetation of ca. 47 million years ago included some taxa that cannot readily be placed in modern families and genera.

Correcting for Replicated Genotypes May Introduce More Problems Than it Solves.

Across the tree of life, many organisms are able to reproduce clonally, via vegetative spread, budding or parthenogenesis. In population genetic analyses of clonally reproducing organisms, it is common practice to retain only a single representative per multilocus genotype. Though this practice of clone correction is widespread, the theoretical justification behind it has been very little studied. Here, I use individual-based simulations to study the effect of clone correction on the estimation of the genetic summary statistics HO, HS, FIS, FST, F''ST and Dest. The simulations follow the standard finite island model, consisting of a set of populations connected by gene flow, but with a variable rate of sexual versus asexual reproduction. The results of the simulations show that by itself, the inclusion of replicated genotypes does not lead to a deviation in the values of the summary statistics, except when the rate of sexual reproduction is less than about one in thousand. However, clone correction can introduce a strong deviation in the values of most of the statistics, when compared to a scenario of full sexual reproduction. For HS and FIS, this deviation can be informative about the process of asexual reproduction, but for FST, F''ST and Dest, clone correction can lead to incorrect conclusions. I therefore argue that clone correction is not strictly necessary, but can in some cases be insightful. However, when clone correction is applied, it is imperative that results for both the corrected and uncorrected data are presented.

Alternative products for breaking dormancy in ‘Reubennel’ plum in subtropical regions

Abstract Plum is a temperate fruit tree and thus shows abundant vegetative bud percentage and flowering following extended periods of low winter temperatures. When adequate periods of low temperatures do not occur, it is necessary to apply products to stimulate bud dormancy break and uniform leaf and flower appearance. This application is more frequently needed when plum trees are grown in the tropics. The objective of this study was to evaluate alternative products for breaking dormancy in ‘Reubennel’ plum in subtropical regions. The experiment was conducted at a site located at 22°22’S, 43°77’W and 1,173 m altitude, with a Cwa climate type. The following treatments were applied to eight-year-old ‘Reubennel’ plum trees in the 2018 and 2019 production cycles: 1) a negative standard composed of only water (control), a positive standard composed of 2) 1.5% hydrogen cyanamide (HC) (Dormex® commercial product) plus 4.5% mineral oil, 3) Erger G® organomineral fertilizer supplemented with 3% calcium nitrate, 4) 5% potassium nitrate and 5) 0.3% copper sulfate. Two liters of the treatment solutions were applied per plant with a sprayer. The effect of the tested products on vegetative bud percentage and flowering capacity, production cycle reduction and production and quality of ‘Reubennel’ plums was evaluated. It was concluded that the chemicals used to break dormancy affected only the phenology of plum trees in this subtropical region and that the application of copper sulfate can be used to break dormancy in these trees.

Molecular Diversity Analysis of in vitro and Irradiated Tomato (Lycopersicon esculentum Mill) Grew Under Salt Stress Expressed by SCoT and ISSR Markers

Tomato buds of cv. Idkawy were cultured in vitro on solid MS medium with 0.2 mg-l BAP. The plantlets that were produced were exposed to different doses of gamma radiation, ranging from 100 to 200 Gy. Afterward, single pieces of nodes were cut and moved to a fresh MS medium with 0.2 mg-l of BAP. The gamma radiation caused a mortality rate of 18.75% to 52.5% among the explants. The surviving plantlets were then cut into single node pieces and transferred to an MS medium containing 0.2 mg-l of BAP, with added NaCl concentrations of either 50 or 100 mM. There was increased mortality of the vegetative buds on the explants with increased salt concentrations. It was shown that the all gamma radiation doses caused reduced the percentage of survival at saline levels. The genetic diversity was assessment by using ten primers for each SCoT and ISSR markers to six irradiated treatments grew under salt stress (100 Gy x 50 mM, 150 Gy x 50 mM, 200 Gy x 50 mM, 100 Gy x 100 mM, 150 Gy x 100 mM, 200 Gy x 100 mM). It was showed that the polymorphism percentage mean of SCoT marker (29.56%) is higher than the ISSR marker (26.78%). The average of PIC values for both markers SCoT and ISSR were 0.197 and 0.288 (PIC ˂0.5), as well as, MI values were 0.077 and 0.081, respectively. In contrast, when considering the number of alleles (Ne), Nei's genetic diversity (H), and Shannon's information index (I) parameters, it was observed that the greatest genetic variation was caused by the combined treatment of 200 Gy x 50 mM NaCl using the SCoT marker. On the other hand, with the ISSR marker, the highest induced genetic variation was seen with the combined treatment of 150 Gy x 50 mM NaCl. The obtained results demonstrate that SCoT marker was more accurate and efficient than ISSR marker for distinguishing and genetic variation analysis of irradiated tomato plantlets grew under salt stress. The relationships within treatments were estimated through cluster analysis (UPGMA) based on SCoT and ISSR analysis.

Shade signals activate distinct molecular mechanisms that induce dormancy and inhibit flowering in vegetative axillary buds of sorghum.

Shoot branches grow from axillary buds and play a crucial role in shaping shoot architecture and determining crop yield. Shade signals inactivate phytochrome B (phyB) and induce bud dormancy, thereby inhibiting shoot branching. Prior transcriptome profiling of axillary bud dormancy in a phyB-deficient mutant (58M, phyB-1) and bud outgrowth in wild-type (100M, PHYB) sorghum genotypes identified differential expression of genes associated with flowering, plant hormones, and sugars, including SbCN2, SbNCED3, SbCKX1, SbACO1, SbGA2ox1, and SbCwINVs. This study examined the expression of these genes during bud dormancy induced by shade and defoliation in 100M sorghum. The aim was to elucidate the molecular mechanisms activated by shade in axillary buds by comparing them with those activated by defoliation. The expression of marker genes for sugar levels suggests shade and defoliation reduce the sugar supply to the buds and induce bud dormancy. Intriguingly, both shade signals and defoliation downregulated SbNCED3, suggesting that ABA might not play a role in promoting axillary bud dormancy in sorghum. Whereas the cytokinin (CK) degrading gene SbCKX1 was upregulated solely by shade signals in the buds, the CK inducible genes SbCGA1 and SbCwINVs were downregulated during both shade- and defoliation-induced bud dormancy. This indicates a decrease in CK levels in the dormant buds. Shade signals dramatically upregulated SbCN2, an ortholog of the Arabidopsis TFL1 known for inhibiting flowering, whereas defoliation did not increase SbCN2 expression in the buds. Removing shade temporarily downregulated SbCN2 in dormant buds, further indicating its expression is not always correlated with bud dormancy. Because shade signals also trigger a systemic early flowering signal, SbCN2 might be activated to protect the buds from transitioning to flowering before growing into branches. In conclusion, this study demonstrates that shade signals activate two distinct molecular mechanisms in sorghum buds: one induces dormancy by reducing CK and sugars, whereas the other inhibits flowering by activating SbCN2. Given the agricultural significance of TFL1-like genes, the rapid regulation of SbCN2 by light signals in axillary buds revealed in this study warrants further investigation to explore its potential in crop improvement strategies.

Galling by Trichilogaster sp. suppresses the growth of Acacia auriculiformis saplings

Pre-release efficacy assessments (PREAs) are used in weed biological control to predict the potential impact of prospective agents. These assessments enable the most damaging agents to be prioritised for host testing and release. Further, the inclusion of this information in release applications enables regulators to consider the benefits of an agent alongside any risks. We conducted a PREA to evaluate the efficacy of Trichilogaster sp., a galling wasp that is being considered for release in Florida to control invasive earleaf acacia, Acacia auriculiformis. This species is multivoltine and primarily galls vegetative buds. We performed a glasshouse trial exposing A. auriculiformis saplings to one generation of the gall wasp to determine the effect of galling on plant performance. We monitored the growth parameters and development of exposed and unexposed saplings every three weeks for twelve weeks. Above-ground and below-ground biomass were measured at the completion of the trial. One generation of galling reduced sapling height by 37.44 % (±5.57), above-ground biomass by 32.19 % (±4.00), and below-ground biomass by 38.26 % (±7.47). Galling also significantly reduced the other key growth parameters of stem weight, leaf weight, total branch length, and the number of nodes, shoot tips, and leaves. This Trichilogaster species significantly damages juvenile A. auriculiformis plants and could be an effective classical biological control agent if released in Florida, especially if it is not limited by a specialist third trophic level.

A bud's life: Metabarcoding analysis to characterise hazelnut big buds microbiome biodiversity

Despite Corylus avellana L. being an economically important shrub species known for its resilience to adverse environmental conditions, it constantly faces attacks from a plethora of biotic entities. Among these, the mite pest Phytoptus avellanae is gaining importance, causing economic losses every year. This mite colonises the new generative and vegetative buds, leading them to become swollen and reddish, and drastically reducing hazelnut production. The biology behind gall formation is still poorly understood. This study provides a qualitative and quantitative description of the microbiome in both healthy and infested buds of two economically important hazelnut cultivars through metabarcoding of fungal ITS and bacterial 16 S. Potentially pathogenic genera such as Fusarium and Pseudomonas were predominant in the infested buds, along with the obligate intracellular bacterial genus Wolbachia. Akanthomyces muscarius was instead isolated from culture-based methods only from the infested buds. These findings could improve the understanding of gall ecology, supporting the management of mite populations, and they could also serve as a milestone for further studies on low-impact, monitoring-driven, and genetically targeted control strategies.

Deep learning with a small dataset predicts chromatin remodelling contribution to winter dormancy of apple axillary buds.

Epigenetic changes serve as a cellular memory for cumulative cold recognition in both herbaceous and tree species, including bud dormancy. However, most studies have discussed predicted chromatin structure with respect to histone marks. In the present study, we investigated the structural dynamics of bona fide chromatin to determine how plants recognise prolonged chilling during the initial stage of bud dormancy. The vegetative axillary buds of the 'Fuji' apple, which shows typical low temperature-dependent, but not photoperiod, dormancy induction, were used for the chromatin structure and transcriptional change analyses. The results were integrated using a deep-learning model and interpreted using statistical models, including Bayesian estimation. Although our model was constructed using a small dataset of two time points, chromatin remodelling due to random changes was excluded. The involvement of most nucleosome structural changes in transcriptional changes and the pivotal contribution of cold-driven circadian rhythm-dependent pathways regulated by the mobility of cis-regulatory elements were predicted. These findings may help to develop potential genetic targets for breeding species with less bud dormancy to overcome the effects of short winters during global warming. Our artificial intelligence concept can improve epigenetic analysis using a small dataset, especially in non-model plants with immature genome databases.

Is <i>Nymphaea rubra</i> Roxb. Ex Andrews-An Apomict?

Studies on several populations of Nymphaea rubra in the Howrah, Hooghly and 24-Parganas districts in West Bengal and Barisal district in Bangladesh reveal that this species, claimed to be a native of Bengal, never sets fruit in nature. The plant propagates though stolons and vegetative buds and, in exceptional cases, by proliferation of flowers. The report of meiotic irregularity and high incidence of polysomaty and pollen sterility is indicative of its apomictic nature. The nomenclature of the plant has been discussed.

Programmed Cell Death Reversal: Polyamines, Effectors of the U-Turn from the Program of Death in Helianthus tuberosus L.

This review describes a 50-year-long research study on the characteristics of Helianthus tuberosus L. tuber dormancy, its natural release and programmed cell death (PCD), as well as on the ability to change the PCD so as to return the tuber to a life program. The experimentation on the tuber over the years is due to its particular properties of being naturally deficient in polyamines (PAs) during dormancy and of immediately reacting to transplants by growing and synthesizing PAs. This review summarizes the research conducted in a unicum body. As in nature, the tuber tissue has to furnish its storage substances to grow vegetative buds, whereby its destiny is PCD. The review's main objective concerns data on PCD, the link with free and conjugated PAs and their capacity to switch the destiny of the tuber from a program of death to one of new life. PCD reversibility is an important biological challenge that is verified here but not reported in other experimental models. Important aspects of PA features are their capacity to change the cell functions from storage to meristematic ones and their involvement in amitosis and differentiation. Other roles reported here have also been confirmed in other plants. PAs exert multiple diverse roles, suggesting that they are not simply growth substances, as also further described in other plants.

Phytochemical Characterization, Antioxidant, and Antimicrobial Activity of the Vegetative Buds from Romanian Spruce, Picea abies (L.) H. Karst.

This study aims to investigate the vegetative buds from Picea abies (spruce), naturally found in a central region of Romania, through a comprehensive analysis of the chemical composition to identify bioactive compounds responsible for pharmacological properties. Using HPLC/derivatization technique of GC-MS and quantitative spectrophotometric assays, the phenolic profile, and main components of an ethanolic extract from the buds were investigated. The essential oil was characterized by GC-MS. Moreover, the antioxidant activity with the DPPH method, and the antimicrobial activity were tested. Heavy metal detection was performed by graphite furnace atomic absorption spectrometry. The main components of the alcoholic extract were astragalin, quercetin, kaempferol, shikimic acid, and quinic acid. A total content of 25.32 ± 2.65 mg gallic acid equivalent per gram of dry plant (mg GAE/g DW) and of 10.54 ± 0.083 mg rutin equivalents/g of dry plant (mg RE/g DW) were found. The essential oil had D-limonene, α-cadinol, δ-cadinene, 13-epimanool, and δ-3-carene as predominant components. The spruce vegetative buds exhibited significant antioxidant activity (IC50 of 53 μg/mL) and antimicrobial effects against Staphylococcus aureus. Furthermore, concentrations of heavy metals Pb and Cd were below detection limits, suggesting that the material was free from potentially harmful contaminants. The results confirmed the potential of this indigenous species to be used as a source of compounds with pharmacological utilities.

Comprehensive Analysis of Flowering Patterns in One-Year-Old Long Shoots of Apple Cultivars with Contrasted Bearing Habits

Before developing orchard management strategies, it is crucial to conduct architectural analysis at the shoot level for the specific type of fruit to be grown. The objective of this study was to analyze flowering patterns in 1-year-old long shoots of three apple cultivars ('Amasya,' 'Braeburn,' and 'Granny Smith') with different bearing behaviors. This analysis aimed to gain a better understanding of their growth dynamics and reproductive activities. The shoot was divided into three consecutive zones (proximal, median, and distal) based on node number. When comparing the number of floral and vegetative buds in the three zones along the shoot, less contrast was observed between alternate-bearing ('Amasya') and regular-bearing cultivars ('Braeburn' and 'Granny Smith'). However, a notable difference in floral bud quality variables was evident in shoot zones between biennial-bearing and regular-bearing cultivars. In 'Braeburn' and 'Granny Smith' with a regular bearing habit, floral bud quality variables remained stable along the shoot. In contrast, 'Amasya' shoots exhibited a gradual increase in floral bud quality from the proximal zone towards the distal zone. This study underscores the significance of floral bud quality, especially the properties of spur leaves along the shoot, in ensuring optimal and consistent productivity. Finally, with the exception of internode length, morphometric traits did not significantly differ between cultivars when considering the entire shoot. However, these differences became apparent when examining successive zones along the shoot.

Potential causal factors of “heart-shaped cladode” malformations in cactus pear (Opuntia ficus-indica (L.) Miller)

The prevalence and severity of pests and diseases are factors that limit productivity and quality in commercial cactus pear plantations in Mexico. Recently, in several cactus pear producing regions the appearance of diverse symptoms associated with “heart-shaped cladodes” has been registered. This disease is characterized by the loss of apical dominance of vegetative shoots leading to abnormal cladode growth. Besides the aesthetic damage, vegetative and floral buds disappear in the zone of invagination, thus reducing productivity. Because to date the causal agent is unknown, this study was conducted to analyze three possible agents, damage by insects, physical damage and phytoplasmas that could possibly cause the symptomatology of “heart-shaped cladode”, aiming to constitute a base line for future studies. The study was conducted under semi-controlled conditions and in the field, using Opuntia ficus-indica cv. Villanueva plants and cladodes. To rule out causal agents that occur naturally in cactus pear productive systems, the following characteristics were analyzed: detected presence of Diabrotica undecimpunctata, simulation of physical damage by puncturing 4- and 13-day-old shoots with a needle, and detection of phytoplasmas with PCR and RFLP. The results of the study showed that, although it feeds on shoots, D. undecimpunctata does not cause the symptoms. The puncture with a needle on the apical part promoted the presence of symptoms. The PCR and RFLP analyses detected the presence of phytoplasmas on both symptomatic and asymptomatic shoots. For this reason, it was not possible to conclude that phytoplasmas are the causal agents of heart-shaped cladode.

Influence of mineral, organic, organomineral fertilization on winter hardiness components of columnar apple tree (<i>Malus domestica</i> Borkh.)

Intensive biological technologies of apple-tree cultivation with application of organic and mineral fertilizers form high nitrogen nutrition, thus leading to prolonged growth of fruit plants and reducing their winter hardiness. Columnar apple tree fail to demonstrate high potential for winter hardiness. Therefore, research into regularities and mechanisms behind the influence of nutritional status of columnar apple tree on indicators of plant winter hardiness is considered relevant. The research was aimed at establishing the influence of mineral, organic, organomineral fertilization on the components of winter hardiness of columnar apple trees grown on podzolic soil. Materials and methods. The research involved the ‘Triumph’, ‘President’, ‘Ostankino’ columnar apple varieties, as well as organic and mineral fertilizers. The experiment was conducted in 2016–2021 in the agrochemical experiment station of the Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow region) on podzolic soil of medium-loam particle size distribution. The experimental design included 4 variants: 1) control without fertilizers; 2) N90K90; 3) organic fertilizers 100 t/ha; 4) N90K90 organic fertilizers 100 t/ha. Naa (ammonium saltpeter), KCl mineral fertilizers were applied annually, organic fertilizer (horse manure with sawdust) was applied in 2014. Winter hardiness components and plant samples were analyzed according to generally accepted methods. According to the research into the influence of mineral, organic, organomineral fertilization on the components of winter hardiness of columnar apple tree (Malus domestica Borkh.) grown on podzolic soil in the conditions of the Moscow region, the fertilizer is found inefficient in terms of providing the optimal level of nitrogen nutrition of columnar apple tree plants, except for ‘Triumph’ variety when getting organic fertilizers at a dose of 100 t/ha. In January, fructose prevailed in the sugars of annual shoots of columnar apple tree plants. The ‘Triumph’ and ‘President’ varieties showed a tendency to increase in the content of fructose and glucose as compared with the control when getting organic fertilizers and their combination with mineral fertilizers. The same tendency was observed in the ‘Ostankino’ variety for the content of ascorbic acid in annual shoots, whereas this indicator of the ‘Triumph’ and ‘President’ varieties demonstrated the opposite trend. The ascorbic acid content in annual shoots in winter appeared consistent with its content in August shoots and remained independent on the content in leaves in August. With a decrease in temperature to -40 °C (component II of winter hardiness), the ‘Triumph ‘and ‘Ostankino’ varieties suffered reversible damage to the vegetative buds from 0 to 2.0 points, the ‘President’ variety introduced with 100 tons/ha organic fertilizers demonstrated an increase in damage to the vegetative buds to 3.17 points. The greatest damage to reproductive buds in the ‘President’ and ‘Ostankino’ varieties (3.85-3.91 on the control) was observed in component II of winter hardiness. The application of mineral and organic fertilizers increased these damages to complete death of reproductive buds. Injuries to bark, cambium in all variants of the studied varieties did not exceed 2.0 points. Wood appeared more damaged in the ‘Ostankino’ variety (up to 4.03 points in the combined application of N90K90 and 100 t/ha of organic fertilizers) as well as in the Triumph variety (up to 3.80 points in the N90K90 variant). As for component III of winter hardiness, an irreversible damage was noted for reproductive buds of the studied varieties in all variants of the experiment. In terms of component IV of winter hardiness, irreversible changes occurred in reproductive buds to the greatest extent (complete death in the ‘Triumph’ and ‘President’ varieties); in the tissue under reproductive buds, to the greatest extent in the ‘President’ variety (3.07 points in the variant of 100 tons/ha of organic fertilizers) and in the ‘Ostankino’ variety (2.76 points in N90K90), at the core, the maximum damage was noted in the N90K90 variant in the ‘Triumph’ (3.22 points) and ‘Ostankino’ (2.76 points) varieties.

Regulatory role of Prunus mume DAM6 on lipid body accumulation and phytohormone metabolism in the dormant vegetative meristem.

Bud dormancy is a crucial process in the annual growth cycle of woody perennials. In Rosaceae fruit tree species, DORMANCY-ASSOCIATED MADS-box (DAM) transcription factor genes regulating bud dormancy have been identified, but their molecular roles in meristematic tissues have not been thoroughly characterized. In this study, molecular and physiological analyses of transgenic apple plants overexpressing the Japanese apricot DAM6 gene (PmDAM6) and Japanese apricot cultivars and F1 individuals with contrasting dormancy characteristics revealed the metabolic pathways controlled by PmDAM6. Our transcriptome analysis and transmission electron microscopy examination demonstrated that PmDAM6 promotes the accumulation of lipid bodies and inhibits cell division in the dormant vegetative meristem by down-regulating the expression of lipid catabolism genes (GDSL ESTERASE/LIPASE and OIL BODY LIPASE) and CYCLIN genes, respectively. Our findings also indicate PmDAM6 promotes abscisic acid (ABA) accumulation and decreases cytokinin (CTK) accumulation in vegetative buds by up-regulating the expression of the ABA biosynthesis gene ARABIDOPSIS ALDEHYDE OXIDASE and the CTK catabolism gene CYTOKININ DEHYDROGENASE, while also down-regulating the expression of the CTK biosynthesis genes ISOPENTENYL TRANSFERASE (IPT) and CYP735A. Additionally, PmDAM6 modulates gibberellin (GA) metabolism by up-regulating GA2-OXIDASE expression and down-regulating GA3-OXIDASE expression. Furthermore, PmDAM6 may also indirectly promote lipid accumulation and restrict cell division by limiting the accumulation of CTK and GA in buds. In conclusion, using our valuable genetic platform, we clarified how PmDAM6 modifies diverse cellular processes, including lipid catabolism, phytohormone (ABA, CTK, and GA) biosynthesis and catabolism, and cell division, in the dormant vegetative meristem.

Pinus sibirica Du Tour в условиях интродукции на примере Полярно-альпийского ботанического сада-института

The study has been conducted at the Polar-Alpine Botanical Garden-Institute, the northernmost botanical garden in Russia (67°38′ N). The aim of this work has been a comprehensive analysis of the condition of Siberian stone pine trees (Pinus sibirica Du Tour) during their introduction in the Arctic. The condition of 8 specimens of the species cultivated at the experimental plot in the town of Apatity has been examined. Their phenological development has been analyzed: the swelling and breaking of the vegetative buds, the end of the elongation and maturation of the needles, the beginning and end of growth of the annual shoots, the lignification of the shoots, the beginning and end of pollen dispersion. The degree of lignification of the annual shoot, the winter hardiness, the habit, the shootforming capacity, the height increment, the generative development and the reproduction in the plantation have also been assessed. The risk of a tree falling has been determined by considering its surroundings and exposure to wind. The root zones, the butts, the trunks, the crown bases, the boughs and the crowns have been examined for the presence of hollows, cracks, decomposition, fungal fruit bodies, damage, weak forks, dead branches, etc. The application of an approach combining the analysis of seasonal development, viability and risk of tree fall is promising for a comprehensive and objective assessment of the condition of Siberian stone pine trees by morphological and phenological characteristics during the introduction to the Arctic zone of the Russian Federation. The phenological rhythm of the studied trees corresponds to the environmental conditions during the introduction to the Polar-Alpine Botanical Garden-Institute named after N.A. Avrorin. Vegetation begins in late May. By the end of August the annual shoots lignify, which indicates the readiness of the plants for the winter period. The close timing of the onset of phenophases and their low variation may indicate a low dependence of the seasonal development of Siberian stone pine on weather conditions during the introduction to the central part of the Kola Peninsula. The trees are winter-hardy, retain the life form inherent to the species, have a high shoot-forming capacity and annual height increment. They reach the generative stage of development. For their propagation in the plantation, it is necessary to attract seed material from other regions. The trees are monocormic, unimucronate and bimucronate. They are characterized by dense crowns. Their apical and lateral shoots are developed. In rare cases, the increment of lateral shoots is reduced. The V-shaped forks have been noted on the stems and a hollow in the butt area has been found on one of the trees. An additional instrumental examination is needed to determine the effect of diseases or pathogens on the stability of the trees.

Effects of green pruning and combine microelement applications on bud fruitfulness, vegetative development and cluster characteristics of ‘Trakya İlkeren’ grape cultivar

Green pruning practices are frequently used in viticulture. These practices provide better light penetration, successful air circulation, prevents air humidity and aids disease control in the grapevine canopy. However, excessive leaf removal inhibits vine growth and good fruit ripening. In this study, the effects of some foliar and canopy management practices on cluster, vegetative growth traits and bud fruitfulness of the following year were investigated. Some green pruning (unproductive shoot removal, leaf removal, shoot tip removal, shoot topping), foliar microelements and green pruning + microlements treatments were applied in ‘Trakya İlkeren’ grape cultivar. Microelement application increased cluster (382.1 g) and berry weight (4.4 g), berry length (19.7 mm) and width (18.2 mm), cluster length (19.5 cm) and width (13.9 cm), berry volume (3.30 cm3) and berry firmness (7.46 N). The highest maturity index was detected in the control group (23.4). While the most intense L* color value was determined in the green pruning + micro element application, the b* color value was determined in the green pruning application. It was determined that leaf area (211.2 cm2), leaf chlorophyll index (32.75 SPAD), shoot diameter (11.13 mm), shoot length (194.71 cm) and internode length (76.81 mm) increased with microelement application. Among the treatments, the most effective application on bud fruitfulness in the following year was at microelement application (1.34 clusters). The effects of the treatments on the amount of Total soluble solids pH, titratable acid and a* color value were not significant. In this study; green pruning + microelement application was recommended for yield and quality sustainability. According to bud fruitfulness results, the highest cluster numbers per node were obtained from pruning with 4 to 10 buds. It is recommended to prune medium or long to obtain higher yields from this cultivar.

Water strategy improves the inflorescence primordia formation of 'Arra 15' grapevine in the Brazilian semiarid region

Failure in irrigation management of grapevines grown in the Brazilian semiarid region can affect bud fertility. Adequate irrigation, considering both the development of bunches in the current cycle and the formation of fertile buds for subsequent cycles, can bring significant advances to viticulture. Therefore, the objective of this research was to investigate the effect of different irrigation levels during flowering on the formation of buds and potential bunches of 'Arra 15' grapevine and its relationship with metabolic processes. A field experiment was carried out in a commercial vineyard in Petrolina, Pernambuco, Brazil, during the 2021 and 2022 seasons. The experiment was designed in randomized blocks with four replications and five irrigation levels (70; 85; 100; 115 and 130% of crop evapotranspiration – ETc) during three production cycles. The variables fertile bud, vegetative bud, dead bud, potential fertility of the basal, median, and apical regions of the branches, number of potential bunches, reducing sugar, total soluble sugar, net photosynthesis, stomatal conductance, transpiration, and relative chlorophyll index were evaluated. The 115% ETc irrigation level improved the number of fertile buds and number of potential bunches. Irrigation level above 115% ETc increased gas exchange and relative chlorophyll index, while 70% ETc increased leaf sugar content. The most appropriate irrigation strategy is the application of 115% ETc during the flowering stage, for the increase of fertile buds and potential bunches of the next cycle, without influencing the vine metabolism. Total soluble sugars are a promising indicator of water deficit during flowering and as an indicator of vegetative bud formation for the next cycle.

Comparative transcriptome analysis and genetic dissection of vegetative branching traits in foxtail millet (Setaria italica).

Two major genetic loci, qTN5.1 and qAB9.1, were identified and finely mapped to the 255Kb region with one potential candidate gene for tiller number and the 521Kb region with eight candidate genes for axillary branch number, respectively. Vegetative branching including tillering and axillary branching are vital traits affecting both the plant architecture and the biomass in cereal crops. However, the mechanism underlying the formation of vegetative branching in foxtail millet is largely unknown. Here, a foxtail millet cultivar and its bushy wild relative Setaria viridis accession were used to construct segregating populations to identify candidate genes regulating tiller number and axillary branch number. Transcriptome analysis using vegetative branching bud samples of parental accessions was performed, and key differentially expressed genes and pathways regulating vegetative branching were pointed out. Bulk segregant analysis on their F2:3 segregating population was carried out, and a major QTL for tiller number (qTN5.1) and two major QTLs for axillary branch number (qAB2.1 and qAB9.1) were detected. Fine-mapping strategy was further performed on F2:4 segregate population, and Seita.5G356600 encoding β-glucosidase 11 was identified as the promising candidate gene for qTN5.1, and eight genes, especially Seita.9G125300 and Seita.9G125400 annotated as B-S glucosidase 44, were finally identified as candidate genes for regulating axillary branching. Findings in this study will help to elucidate the genetic basis of the vegetative branching formation of foxtail millet and lay a foundation for breeding foxtail millet varieties with ideal vegetative branching numbers.

Modelling the architecture of hazelnut (Corylus avellana) Tonda di Giffoni over two successive years

Abstract Hazelnut (Corylus avellana) cultivation is increasing worldwide. A 3D model of its structure could improve managerial techniques such as pruning. This study aims to analyse, over two successive years, hazelnut architectural development to implement a functional structural plant model. One hundred and four one-year-old shoots of own-rooted hazelnut trees were selected and analysed in winter 2020 and 2021. Exploratory analyses, generalized linear models and multinomial regression models were used to describe the architectural processes. The existence of sylleptic shoots on hazelnut one-year-old shoots, characterized by the presence of the male inflorescence on apical position, was detected. Along proleptic shoots, the branching pattern was described by (i) blind nodes located in the proximal part (ii) sylleptic shoots and mixed buds in the median part (iii) vegetative buds in the distal part. Apical bud died during the growing season, suggesting that Tonda di Giffoni has a sympodial branching. The models revealed dependencies among buds located at the same node, in the case of proleptic shoots. Especially, the probability of a bud bursting depended on both its type (i.e. mixed or vegetative) and the presence of other buds, either mixed or vegetative. Based on these local models and on a flow diagram, which defines the steps that led to the construction of hazelnut tree architecture, the first functional–structural plant model of hazelnut tree architecture was built. Further experiments will be needed and should be repeated over the following years to extend this study towards the juvenile phase and tree architecture over time.