Key message This study proposed the combination of PR26S and PP1 as a good choice for RT-qPCR normalization in pecan under abiotic stress, developing kernels, grafting, and various tissues. Abstract Reference gene selection is an essential pre-requisite to generate reliable results in real-time quantitative polymerase chain reaction (RT-qPCR) analysis. However, studies regarding systematic validation

The net photosynthetic rate (A), stomatal conductance (gs), and transpiration rate (E), chlorophyll content, and midday xylem water potential (Ψmd) of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe trees were studied in a natural stand (Burdur-Aziziye, Turkey) for the first (2015), second (2016) and third (2017) years after precommercial thinning (PCT) to better understand the physiological and

Key message We performed a comparative transcriptome combined with morpho-physiological analyses between two differential cold tolerance in two contrasting apricot cultivars. The revealed candidate genes potentially were identified by differential expression analysis. Apricot (Prunus armeniaca L.) is a major (non-wood product) forest tree species that is adversely affected by spring frost. However

Key message Flow within internal secretory systems derived from autolyzing epithelia in kino-producing angiosperms may have lower metabolic energy costs. This presents physiological advantages and possibly constitutes an evolutionary step of these species compared to resin flow in conifers in using internal secretory systems in plant defence mechanisms. Abstract Kino is a plant exudate, rich in polyphenols

Black walnut (Juglans nigra L.) is a light-demanding, competition-intolerant, and tall forest tree species, introduced in Europe from North America at the beginning of the seventeenth century. It has an important economic role in Europe for producing wood and fruits, in agroforestry systems, as an ornamental tree for parks and avenues, for rehabilitation/restoration of degraded lands. The best sites

Key message The diameter at breast height of the largest sprout per coppiced stool proved to be accurate for the total sprout biomass estimates at stand level. Abstract Traditional coppicing is one of the oldest silvicultural systems for biomass production. However, a quick and simple biomass estimate methodology across the entire growth period is lacking. The objective of this study was to find the

Key message The investigation provides initial knowledge on the distribution and evolution of the high and low methyl salicylate-producing trait in the Betula genus. Mislabelled birch species could be identified and removed. Abstract The genus Betula is the largest group of ecologically and economically dominant perennial woody plants in subalpine forests. The taxonomy of Betula is complex due to an

Key message Xylem functionality is the primary determinant of the Ca relations of developing sweet cherry. Calcium influx is positively related to transpiration and decreases as xylem functionality is progressively lost during development. Abstract Fruit calcium (Ca) may be associated with susceptibility to rain cracking in sweet cherry but little background information is available on the fruits’

Changes in leaf size have been demonstrated to considerably affect leaf hydraulic properties, which in turn impact plant photosynthesis and productivity. In this study, we selected five genotypes from four coffee species (Coffea spp.) with highly contrasting individual leaf areas (from 25 to 280 cm2) to test whether changes in foliar area result in anatomical alterations and ultimately changes in leaf

Key message Beech trees growing in biodiverse patches in Belgium have higher radial growth and are less physiologically sensitive to drought than those in monocultures. Forest diversification therefore alleviates the negative effects of drought on beech. Abstract Common beech, a widespread and economically important tree species in Europe, is known to be drought sensitive. For ensuring its survival

Key message This study revealed the ABA-dependent signaling pathway and flavonoid synthesis pathway of sea buckthorn under drought conditions from plant physiology and gene expression levels. Abstract As climate changes and temperatures rise, sea buckthorn (Hippophae rhamnoides L.) is increasingly exposed to numerous challenges, particularly aridity. In this study, the leaves of sea buckthorn were

Key message Restricted access of light for stems reduced carbon acquisition there and limited the biomass growth of the roots. Abstract Light access can affect the microatmosphere within stems, creating favourable conditions for photosynthesis. We tested the hypothesis that stem photosynthesis modifies carbon allocation within plants and also can affect root growth. To verify this hypothesis, parts

Key message This paper shows the intraspecific plant responses in leaf morphology, herbivory and FA between mature and successional tropical dry forests, as well as the difficulty associated with understanding the relationship between FA and herbivory Abstract Understanding the processes that affect biotic interactions during secondary succession has implications for the maintenance of species diversity

Key message Understory dwarf bamboo mitigated soil N competition with co-existing canopy oak trees by foraging in deeper soils and increasing dependence on N forms that differ from those used by canopy trees. Abstract Nitrogen (N) competition among co-existing plant species utilizing different mycorrhiza types was explored through the investigation of N sources of oak trees and dwarf bamboo. Vertical

Key message K/Zn application by spraying at bud swell stage and green tip stage improved freezing tolerance of pistachio flowers due to increased antioxidant enzymes, soluble proteins, soluble carbohydrates, total phenolic and proline contents as well as decreased lipid peroxidation and H2O2 content in flower. Abstract Spring frost injury to blossoms has been a severe problem in pistachio-harvesting

Key message Year-round observation suggests that sap flow in growing season represents species-specific transpiration characteristics and sap flow of deciduous broadleaved species in non-growing season is related to daily changes in stem diameter. Abstract Year-round observation is necessary to investigate species-specific characteristics of sap flow and its possible contribution in non-growing season

Key message The lack of elevational changes in electrical resistivity in Pinus cembra trunks indicated consistent growth and hydraulics across elevations. Though, electrical resistivity tomograms exhibited pronounced temperature-driven seasonal changes. Abstract Alpine conifers growing at high elevation are exposed to low temperatures, which may limit xylogenesis and cause pronounced seasonal changes

Key message Genome-wide characterization and development of first set of polymorphic Class I SSRs markers in pomegranate (Punica granatum L.) through in silico analysis using the draft genome sequence of pomegranate cv. Dabenzi (296 Mb) as reported by Qin et al. (2017). Abstract The availability of the draft genome sequence of pomegranate cv. Dabenzi presents unprecedented opportunities for the development

Key message Under severe drought, growth of Norway spruce suffered much more than European beech. Norway spruce benefited from growing in the environment of beech, and both species acclimated slightly to 5 years of experimentally extended drought. Abstract Recent studies show that the detrimental effects of drought on stand growth are mitigated when the stand contains mixed tree species. We analysed

Key message A survey of theEucalyptus grandis genome revealed the presence of 54 laccase genes. Their tissue-specific and stress-induced expression patterns suggest a role in lignification and adaptation to abiotic stresses. Abstract Laccases are multicopper oxidases that play important roles in the oxidation of monolignols during lignin biosynthesis and are reported to be functionally involved in

Key message A new Tau class GST gene was cloned from Pinus brutia Ten. cDNA sequence was analysed for conserved sequences. Substrate specificity, optimum pH, and temperature values of the recombinant PbGST Tau enzyme were determined. Abstract Tau class glutathione S-transferases (GSTs) are essential enzymes for detoxification in plants. To date, a lot of the members of this family have been characterized

Key message Autumn flooding reduced nitrogen uptake and fine root mass. Leaf nitrogen resorption increased, but overall autumn nitrogen accumulation was negligible in flooded seedlings. Subsequently, spring survival and growth were decreased. Abstract Since nitrogen (N) is often limiting in terrestrial ecosystems, N is conserved in trees by resorption before leaf senescence. Bottomland forests are

Key message This non-invasive clearing technique allows for deep clear imaging of plant tissue and 3D structural analysis of leaf cells. Abstract Optical-clearing technology allows the reduction of light scattering and absorption in internal biological tissues. This technology allows microscopy techniques, such as confocal laser scanning microscopy, to obtain structural information deep within the

Key message Our study shows for the first time a complete guabiroba micropropagation system with acclimatized plants. BA was the best plant growth regulator for multiplication and IBA for rooting. Abstract Campomanesia xanthocarpa O. Berg (Myrtaceae), popularly known as guabiroba, is a woody species native to Brazil, important for its potential as a medicinal plant and fruit tree. For the first time

Key message BplSPL1 gene was identified in Betula platyphylla Suk, and its sequence features and gene function expression have provided useful information for further studies on function. Abstract SQUAMOSA promoter-binding protein-like (SPL) are plant-specific transcription factors that play an important regulatory role in plant growth and development. In this study, an SPL gene, BplSPL1, was cloned

Key message Ca2+ induces adaptive response to low P stress through increased root growth and expansion, but plays minor or no role in remobilization of P in leaf tissues or in maintaining membrane integrity. Abstract The role of calcium (Ca2+) in signaling environmental stress has been demonstrated; however, its role in signaling low phosphorus (P) stress and subsequent adaptive responses in trees

Although wood anatomical features can provide yearly resolved climatic information at sub-seasonal resolution, the occurrence of intra-annual density fluctuations (IADFs) might be triggered by several abiotic factors under different ecological settings. Here, we use information on cambial age and tree-ring width to standardize the frequency of IADFs in European black pines from three different mountain

Key message This is a descriptive study on leaf ontogeny, showing the main morphological and physiological changes during development of leaves from young plants in three Eucalyptus genotypes. Abstract A descriptive study on key morphological and physiological features during leaf ontogeny in three genotypes—AEC 144, CO 1407 and VCC 865—of Eucalyptus young plants was performed. The work was developed

Key Message Fine roots with thick diameter preferentially elongated into disturbed soil space, indicating positive invasion of pioneer roots that recolonize distal root systems. Abstract Fine roots and their morphological traits are related to below-ground resource dynamics at physiological and ecological levels. Established approaches for investigating fine root dynamics inevitably cause artificial

Key message This study aims to reveal the developmental process and structure of seeds and oil bodies of tree peony, to provide a scientific basis for the development and utilization of such woody oil plants. Abstract In this study, the fruits of P. ostii were selected as the research material to examine the changes during the development of fruits and seeds, the structural changes of the endosperm

Key message Higher temperatures are changing the geographical locations in which Pinus tabulaeformis plantations thrive. Future plantations should be located in the warmer, wetter regions of northern China. Abstract The adaptability of fragile plantation ecosystems to environmental change, especially in our currently warming climate, has become an important issue. We studied the growth of Pinus tabulaeformis

To clarify the photosynthetic physiological response of mulberry seedlings under mixed saline–alkali stress, different saline–alkali combinations were prepared to study its effect on leaf water content, chlorophyll content, and changes of chlorophyll fluorescence parameters of mulberry seedlings leaves. Different saline–alkali combinations were composed of three salt concentrations (50, 100, and 200 mmol L−1)

Key message Walnut production in California depends on the performance of three clonal hybrid rootstocks, and this study provides evidence that roots of genotype RX1 exhibit unique properties to cope with water stress induced by drought. Abstract Three hybrid genotypes RX1 (Juglans microcarpa × J. regia), Vlach and VX211 (both J. hindsii × J. regia) are the most commonly used rootstocks for walnut

Key message Climate responses of radial growth of major hardwood species growing in a cool temperate forest in Japan were clarified by dendrochronological analysis combining the phenology observation of radial growth. Abstract To better understand which climate factors limit the radial growth of major hardwood species growing in a cool temperate forest in Japan, we clarified the phenology of radial

Key message High-density airborne laser scanning can be used to generate metrics that help characterize and differentiate the structure of Douglas-fir across three genetic levels at three different planting spacings. Abstract In British Columbia, Canada, Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] selective breeding is used to develop genetically improved regeneration stock. To evaluate realized

Key message Baldcypress, a long-lived species of riparian habitats, is sensitive to interannual climate variability. The annual radial growth is associated with the Standardized Precipitation Evaporation Index (SPEI) and Palmer Drought Severity Index (PDSI), both depending on a water balance. Abstract The baldcypress (Taxodium mucronatum Ten.) is a long-lived species and Mexico’s national tree. The

Key message Providing an improved protocol for cloning of Picea abies (L.) H. Karst. mature trees via Agrobacterium rhizogenes. Abstract In reforestation programs, rejuvenation of superior genotypes is of great importance in helping juvenile rootstock production. In this regard, the use of plant tissue culture to produce axillary and/or adventitious shoots from explants of mature trees has been the

Key message Embryonic axes of acorns have greater variability of mass than cotyledons or pericarp. Above/below ground seedling mass depends on oak species. Abstract Species of the genus oak are of great importance for forest ecosystems in almost all of the Holarctic. Knowledge of the diversity of the size of acorns and their parts would allow better use of the opportunity of genetic resources storage

Key message Two months of drought or waterlogging conditions did not induce carbon starvation in Castanea sativa. Carbohydrate dynamics in treated plants provide evidence of why this species adapts well to dry but not to waterlogging conditions. Abstract Drought and flooding events, which cause water and oxygen deprivation in tree roots, are expected to occur more frequently due to climate change.

Key message Analysis of polyamines and amino acid profiles in Araucaria angustifolia immature seeds from two mother tree genotypes in 2 consecutive years, and their association with the establishment of embryogenic cultures. Abstract Polyamines (PAs) and amino acids are an important source of nitrogen in plants. They are known to participate in plant development and their levels are associated with

Key message Physiological and metabolic analysis showed the difference in drought tolerance and revealed the common and specific metabolic regulations in Salix sinopurpurea and Salix suchowensis. Abstract Willows (Salix spp.) are important woody plants as promising sources for sustainable and renewable biomass. However, drought is highly detrimental to their growth and development. Deciphering the

Camellia nitidissima is an endangered species whose flowers are bright yellow. In the past 50 years, habitat changes caused by climate and human activity have greatly reduced the extent and size of natural populations of C. nitidissima. Here, to provide a fundamental basis for this plant’s protection and utilization, the genetic diversity and genetic structure of C. nitidissima natural populations

Key message In Sakhalin fir trees from nine different source elevation provenances, we found genetic differentiation of traits related to mechanical reinforcement, hydraulic efficiency, and photosynthetic capacity. Abstract Climatic conditions change with elevation and trees must cope with the resulting variation in stresses. Thus, trees may differentiate into elevational ecotypes with genetic-based

Key message The growth of UCB-1 pistachio rootstock seedlings in the earliest years is a poor predictor of subsequent growth. Therefore, rogueing during the 1st years of growth is not effective. Abstract The UCB-1 hybrid, produced from a controlled cross between Pistacia atlantica (female) and P. integerrima (male), is the main pistachio rootstock used in the USA. Variation has been observed in orchards

Key message We developed and identified a new set of polymorphic EST-SSR markers in Sorbus pohuashanensis (Hance) Hedl. and generated an optimal sampling strategy. Abstract Sorbus pohuashanensis (Hance) Hedl. is indigenous to northern China and prized for its graceful appearance and seasonal variations in foliage color. However, only a few molecular biology studies have been conducted on this species

Orientation of leaves in a mature hemiboreal mixed broadleaf stand (the Järvselja RAMI birch stand) was measured using the high-density point cloud of terrestrial laser scanner hits. Leaf normal distribution in the upper part of crowns of tall aspen and birch trees is almost spherical, and slightly planophile in the lower part of crowns. Leaves of alder trees are rather planophile in the upper part

Key message In a grafted citrus tree, the leaf and root metabolic composition and the response to the phloem-limited pathogenic bacterium Candidatus Liberibacter asiaticus are influenced by the rootstock. Abstract Eleven different citrus rootstock varieties were investigated for their influence on the grafted tree response to Candidatus Liberibacter asiaticus (CLas), the pathogen associated with Huanglongbing

Poplar spiral gall aphid (Pemphigus spyrothecae) forms galls on the petiole in poplars (Populus) and mass infestations are frequent in poplar stands, but how these parasite gall infestations can affect the leaf lamina structure, photosynthetic rate and constitutive and stress volatile emissions is unknown. We investigated how the infestation by the petiole gall aphids affects lamina photosynthetic

High-resolution time series of stem radius variations (SRVs) record fluctuations in tree water status and temporal dynamics of radial growth. The focus of this study was to evaluate the influence of tree size (i.e., saplings vs. mature trees) and soil water availability on SRVs. Dendrometers were installed on Pinus sylvestris at an open xeric site and on Picea abies at a dry-mesic site, and the SRVs

KEY MESSAGE The specific leaf area of European larch depends on branch height and canopy depth, indicating that both, the effect of hydraulic limitations and low water potentials in greater branch heights, and light availability affect specific leaf area. ABSTRACT Specific leaf area (SLA) is defined as the ratio between projected leaf area and needle dry mass. It often serves as parameter in ecosystem

KEY MESSAGE Understanding the mobility and distribution of chemical elements in wood is necessary to apply dendrochemistry. Crystals are likely stable and could be used to analyze changes in nutrient supply. ABSTRACT Dendrochemistry uses the variation in wood chemical composition to infer about past environmental conditions and possible effects on tree growth. Elemental or isotopic variation might

KEY MESSAGE Variability in xylem and phloem phenology among years and species is caused by contrasting temperatures prevailing at the start of the growing season and species-specific sensitivity to drought. ABSTRACT The focus of this study was to determine temporal dynamics of xylem and phloem formation in co-occurring deciduous and evergreen coniferous species in a dry inner Alpine environment (750

We applied dendroclimatological techniques to determine long-term stationarity of climate-growth relationships and recent growth trends of three widespread coniferous tree species of the central Austrian Alps, which grow intermixed at dry-mesic sites within a dry inner Alpine environment (750 m asl). Time series of annual increments were developed from > 120 mature trees of Picea abies, Larix decidua

Lammas shoots are flushes formed by some woody species later in the growing season. Having less time to develop, tissue formation is suggested to be incomplete leading to a higher peridermal water loss during consecutive months. In this study, we analysed morphological and anatomical parameters, peridermal conductance to water vapour and the level of native embolism in mid-winter and late-winter of

The tree constitutes an ecosystem in which microorganisms play an essential role in its functionality. Interactions that microorganisms establish with plants may be beneficial or detrimental and are of extreme importance in the exploitation of trees in agriculture as crop production systems. Fruit trees, especially pomefruit trees including apple, pear and several ornamentals are of great economic

Brown spot of pear is a fungal disease producing high economical losses in several pear-growing areas in Europe. Fungicide applications during the growing period either at fixed schedule or delivered according to the BSPcast forecasting system are not enough to control the disease under favorable conditions. New strategies have been introduced to control the inoculum production using sanitation methods

The genus Erwinia includes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees (E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwinia sp. from Japan) cause similar symptoms, but differ in their degrees of aggressiveness, i.e. in symptoms, host range or both. The presence of plasmids of similar size, in the range of 30 kb, is a common characteristic

Several old cultivars, and breeding clones of European pear Pyrus communis L. originating from Belgium, England, Sweden, and Switzerland were evaluated for their resistance/susceptibility to fire blight. Studies were carried out during three consecutive years 2007-2009 in the greenhouse of Warsaw University of Life Sciences, Poland. Strain 691 of Erwinia amylovora was used for artificial infection

Acoustic emission (AE) and radial shrinkage were compared between fully saturated fresh and pre-dried Norway spruce sapwood during dehydration at ambient temperature. Hydraulic conductivity measurements, anatomical investigations on bordered pits and X-ray computed tomography (CT) scans were done to search for possible AE sources other than the breakage of the water columns inside the tracheids. Both

The aim of this study was to investigate bending stiffness and compression strength perpendicular to the grain of Norway spruce (Picea abies (L.) Karst.) trunkwood with different anatomical and hydraulic properties. Hydraulically less safe mature sapwood had bigger hydraulic lumen diameters and higher specific hydraulic conductivities than hydraulically safer juvenile wood. Bending stiffness (MOE)