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We used fast chlorophyll fluorescence transients (OJIP) to study provenance-related differences in photosynthetic performance and the magnitude of day-to-day chlorophyll fluorescence (ChlF) variation in northern (67° N) and southern (62° N) silver birches in a common garden at 62° N. ChlF transients were measured five times during two weeks in the middle of summer to avoid seasonal variation. Differences in growth and leaf morphological traits between the provenances were also examined. The northern trees had higher chlorophyll content, larger leaf areas, and higher leaf fresh and dry mass than the southern trees, but the leaf mass per area did not differ between the provenances. The southern trees were taller and showed higher annual shoot growth than the northern trees. For all the ChlF parameters, day-to-day variation was significant and followed the same pattern for both provenances with no significant provenance × day interaction, suggesting a similar response to environmental variation. The northern provenance had higher values in parameters related to the reduction of end electron acceptors at the Photosystem I (PSI) acceptor side as probed by ChlF. This and higher values for performance indices PIabs and PItot in northern than in southern trees suggest higher photosynthetic performance of northern trees in line with the latitudinal compensation strategy. Provenance differences in these parameters increased towards the end of the measurement period, suggesting preparation for earlier growth cessation in northern trees triggered by the shortening day length. The study shows that provenance differences in ChlF can be relatively stable regardless of environmental variation but might be influenced by physiological alterations in preparation for future changes in environmental conditions. [ABSTRACT FROM AUTHOR]

European beech (Fagus sylvatica L.) is becoming one of the go-to species in reconstructing declining conifer stands in Europe under climate change. Assisted migration may be considered when looking for suitable beech seedlings. Knowledge about the photosynthetic performance of beech seedlings is fundamental to understanding an essential part of their growth and survival potential in different planting conditions. We investigated the within-provenance variation in photosynthetic performance driven by altitude in contrast to inter-provenance variation given by geographical distance. The experiment was conducted on seedlings replanted in a Danish common garden comprising a cluster of provenances with various altitudinal subgroups transplanted from the Calabria region (Italy) and two local Danish provenances. Provenance and within-provenance variation in chlorophyll fluorescence (ChlF) kinetics, gas exchange (GE), flushing, and senescence were assessed. ChlF measurements revealed within-provenance differences based on altitude of origin and could distinguish between the two Danish provenances. In contrast, GE parameters detected variation in the geographical distance among Italian provenances. High-elevation subgroups of Italian provenances showed the best leaf-level photosynthetic performance in Danish weather conditions with high precipitation levels. Altitude of origin can be a significant source of withinprovenance variation. We demonstrated that assessing this variation in young trees may be instrumental in maximizing the potential of provenance variation across diverse planting sites. [ABSTRACT FROM AUTHOR]

Plant metabolism response to insect herbivores is the central theme of this publication. Genetically uniform individuals of European aspen (Populus tremula) were exposed to recurrent feeding by spongy moths (Lepidoptera) at specific time intervals. Changes in physiology, contents of phenolics and saccharides were quantified over the first hour. The unconventional experiment design, integrating analytical methods, and timeline led to the revealing of unexpected dynamics in plant metabolism. The time interval between herbivory initiation and sample collection revealed a pivotal moment, with induced defense activating strongly after 5  min of chewing resulting in an increase in catechin and procyanidin B1. After 10  min, a shift to a tolerant strategy occurs and induced substance concentrations return to control levels. Delayed physiological response was recorded as the first significant difference in transpiration between affected and nonaffected plants and was found after 10  min. A different strategy in exploitation of saccharides after spongy moths infestation was applied because the pool of selected saccharides was rising in the leaves but decreasing in the roots. Placing our results in the context of existing knowledge highlights the uncertain conceptual basis behind the often rigid and definitive classifications in induced plant defense or tolerance strategy. [ABSTRACT FROM AUTHOR]

The ecological significance of Scots pine (Pinus sylvestris L.) in Europe, especially in areas devastated by bark beetles, has led to its consideration as a substitute for Norway spruce. This pioneering species boasts sun and drought tolerance, fast growth, and wood industry value. To gauge its potential, we examined two ecotypes across two test sites over two years, focusing on height and growth increment. Through statistical analysis employing R software and linear mixed models, we assessed heritability, genotype by environment interaction, and spatial correlations. Both ecotypes exhibited significant differences in height and increment, varying by year and site. Heritability was higher in the second year, with increment showing greater stability. Genetic correlations between sites were evident, suggesting stable increment ranking across locations. These findings underscore the role of ecotypic variation in Scots pine growth, advocating for its consideration in reforestation. Acknowledging such dynamics is vital for effective forest management and reforestation in Central Europe, promoting sustainability and informed decision-making. Further research will enhance this understanding of preserving and enhancing the region's tree populations. [ABSTRACT FROM AUTHOR]

Norway Spruce (Picea abies (L.) H. Karst.), a timber species of significant economic and ecological importance in the Northern Hemisphere, faces increasing threats imposed by drought and bark beetle infestation intensified by ongoing climate change. Despite the extensive mortality within stands, a small proportion of mature trees remarkably survive during severe bark beetle outbreaks. Hypothesizing that bark beetle resilience is genetically determined and thus is under natural selection, we anticipated that there is a genetic variation in genome regions linked to the respective resistance in surviving trees. In the Bohemian Forest, restricted to the area of the Czech–Austrian–German border, we identified those resistant individuals, referred to as the "Last Trees Standing" (LTS). Concurrently, we collected reference samples from randomly selected individuals from natural regeneration within concerned sites (seedlings, young trees) and in adjacent unaffected stands (mature trees). Genomic data were generated on a 50K SNPs genotyping array. We conducted a population genetic study based on the Discriminant Analysis of Principal Components (DAPC) method as well as the Genome-Wide Association Study (GWAS). We identified 12 markers (SNPs) significantly associated with tree survival using this approach. Three of those SNPs are located within the genes with the known function in Arabidopsis thaliana orthologs. After further confirmation, we argue that the identified SNPs can be instrumental in identifying trees of higher resistance to bark beetle infestation. [ABSTRACT FROM AUTHOR]

As a result of climate change, Norway spruce (Picea abies [L.] Karst.) is dying across Europe. One of the primary reasons for this is the cultivation of unsuitable spruce provenances and ecotypes. This study deals with the growth and genetics of the ecotypes of Norway spruce, the most important tree species of the Czech Republic. At the study site, namely Cukrák, an experimental site was established in 1964 to plant three basic spruce ecotypes: low-elevation (LE), medium-elevation (ME) and high-elevation (HE) ecotype. A dendrometric inventory, dendrochronological sampling and genetic analyses were carried out on individual trees in 45 to 46 years old spruce stands. The ME ecotype was the most productive in terms of its carbon sequestration potential, while the HE ecotype had the lowest radial growth. All ecotypes exhibited a noteworthy negative correlation between tree-ring growth and seasonal temperature, annual temperature, previous year September to current year August temperature, June to July temperature, as well as individual monthly temperatures from previous May to current August. The relationship of annual and seasonal precipitation to growth was significant only for the LE and ME ecotypes, but precipitation from previous year September to current year August and precipitation from current June to July were the most significant for all ecotypes, where the ME had the highest r value. The HE ecotype does not adapt well to a dry climate and appears to be unsuitable compared to the other ecotypes under the studied conditions. This study also documented intra-population genetic variation within years of low growth, as evidenced by significant clonal heritability. The selection of the appropriate spruce ecotypes is essential for the stability and production of future stands and should become an important pillar of forest adaptation to climate change. [ABSTRACT FROM AUTHOR]

The JIP test, based on fast chlorophyll fluorescence (ChlF) kinetics and derived parameters, is a dependable tool for studying photosynthetic efficiency under varying environmental conditions. We extracted additional information from the whole OJIP and the normalized variable fluorescence (Vt) transient curve using first and second-order derivatives to visualize and localize points of landmark events. To account for light-induced variations in the fluorescence transient, we present a time-adjusted JIP test approach in which the derivatives of the transient curve are used to determine the exact timing of the J and I steps instead of fixed time points. We compared the traditional JIP test method with the time-adjusted method in analyzing fast ChlF measurements of silver birch (Betula pendula) in field conditions studying diurnal and within-crown variation. The time-adjusted JIP test method showed potential for studying ChlF dynamics, as it takes into account potential time shifts in the occurrence of J and I steps. The exact occurrence times of J and I steps and other landmark events coincided with the times of significant differences in fluorescence intensity. Chlorophyll fluorescence parameters were linearly related to photosynthetic photon flux density (PPFD) at different times of day, and the values obtained by the time-adjusted JIP test showed a stronger linear regression than the traditional JIP test. For fluorescence parameters having significant differences among different times of day and crown layers, the time-adjusted JIP test resulted in more clear differences than the traditional JIP test. Diurnal ChlF intensity data indicated that differences between the southern and northern provenance were only evident under low light conditions. Taken together, our results emphasize the potential relevance of considering the time domain in the analysis of the fast ChlF induction. [ABSTRACT FROM AUTHOR]

Norway spruce has a wide natural distribution range, harboring substantial physiological and genetic variation. There are three altitudinal ecotypes described in this species. Each ecotype has been shaped by natural selection and retains morphological and physiological characteristics. Foliar spectral reflectance is readily used in evaluating the physiological status of crops and forest ecosystems. However, underlying genetics of foliar spectral reflectance and pigment content in forest trees has rarely been investigated. We assessed the reflectance in a clonal bank comprising three ecotypes in two dates covering different vegetation season conditions. Significant seasonal differences in spectral reflectance among Norway spruce ecotypes were manifested in a wide-ranging reflectance spectrum. We estimated significant heritable variation and uncovered phenotypic and genetic correlations among growth and physiological traits through bivariate linear models utilizing spatial corrections. We confirmed the relative importance of the red edge within the context of the study site's ecotypic variation. When interpreting these findings, growth traits such as height, diameter, crown length, and crown height allowed us to estimate variable correlations across the reflectance spectrum, peaking in most cases in wavelengths connected to water content in plant tissues. Finally, significant differences among ecotypes in reflectance and other correlated traits were detected. [ABSTRACT FROM AUTHOR]

Key message: The lack of efficient phenotyping capacities has been recognized as a bottleneck in forestry phenotyping and breeding. Modern phenotyping technologies use systems equipped with various imaging sensors to automatically collect high volume phenotypic data that can be used to assess trees' various attributes. Context: Efficient phenotyping has the potential to spark a new Green Revolution, and it would provide an opportunity to acquire growth parameters and dissect the genetic bases of quantitative traits. Phenotyping platforms aim to link information from several sources to derive knowledge about trees' attributes. Aims: Various tree phenotyping techniques were reviewed and analyzed along with their different applications. Methods: This article presents the definition and characteristics of forest tree phenotyping and reviews newly developed imaging-based practices in forest tree phenotyping. Results: This review addressed a wide range of forest trees phenotyping applications, including a survey of actual inter- and intra-specific variability, evaluating genotypes and species response to biotic and abiotic stresses, and phenological measurements. Conclusion: With the support of advanced phenotyping platforms, the efficiency of traits phenotyping in forest tree breeding programs is accelerated. [ABSTRACT FROM AUTHOR]

We investigated the genetic structure of three phenotypically distinct ecotypic groups of Norway spruce (Picea abies) belonging to three elevational classes; namely, low- (acuminata), medium- (europaea), and high-elevation (obovata) form, each represented by 150 trees. After rigorous filtering, we used 1916 Genotyping-by-Sequencing generated SNPs for analysis. Outputs from three multivariate analysis methods (Bayesian clustering algorithm implemented in STRUCTURE, Principal Component Analysis, and the Discriminant Analysis of Principal Components) indicated the presence of a distinct genetic cluster representing the high-elevation ecotypic group. Our findings bring a vital message to forestry practice affirming that artificial transfer of forest reproductive material, especially for stands under harsh climate conditions, should be considered with caution. [ABSTRACT FROM AUTHOR]

Fast kinetics of chlorophyll a fluorescence in three Norway spruce ecotypes was investigated. Spruce ecotypes that come from different parts of the provenance regions were used to establish a common garden experiment in Central Bohemia (Czech Republic) in 1972. The hypothesis was based on the presumption that high-mountain spruce ecotype will benefit less from plain site compared to the mountain and lowland one after prolonged period of drought in 2018. FluorPen FP 110, spectrophotometer, and pressure chamber of Scholander type were used for fast kinetics of chlorophyll fluorescence induction, chlorophyll content, and water potential measurement. With exception of selected structural parameters, quantum yield of photosystem II (φP0) values did not signify any kind of stress so did the performance index (PIABS) The experiment confirmed high adaption potential for high-mountain spruce ecotype planted in low elevations. [ABSTRACT FROM AUTHOR]

The original article can be found online at https://doi.org/10.1007/s11120-023-01033-x.Photosynthesis Research (2023) 157:133–146https://doi.org/10.1007/s11120-023-01033-xThe original article has been corrected: Figure legends 3 and 5 had been inversed and have now been correctly rearranged.Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.By Olusegun Olaitan Akinyemi; Jaroslav Čepl; Sarita Keski-Saari; Ivana Tomášková; Jan Stejskal; Sari Kontunen-Soppela and Markku KeinänenReported by Author; Author; Author; Author; Author; Author; Author [Extracted from the article]

Serratia marcescens forms different colony patterns under distinct conditions. One of them is the concentric fountain-shaped pattern with pigmented center followed by unpigmented ring and pigmented rim. In this work, we study this pattern formation by construction of the mathematical model able to display this pattern based on putative metabolical traits, supported by series of experiments and by references. A pattern formation of such colony type depends on the disposition of glucose and amino acids, and is accompanied by a pH change in the agar medium. In this paper, we confirm that a metabolic activity of growing colony alters its environment which subsequently changes the colony formation. Presented model corresponds well with the real colony behaviour. [ABSTRACT FROM AUTHOR]

Current knowledge of the genetic mechanisms underlying the inheritance of photosynthetic activity in forest trees is generally limited, yet it is essential both for various practical forestry purposes and for better understanding of broader evolutionary mechanisms. In this study, we investigated genetic variation underlying selected chlorophyll a fluorescence (ChlF) parameters in structured populations of Scots pine (Pinus sylvestris L.) grown on two sites under non-stress conditions. These parameters were derived from the OJIP part of the ChlF kinetics curve and characterize individual parts of primary photosynthetic processes associated, for example, with the exciton trapping by light-harvesting antennae, energy utilization in photosystem II (PSII) reaction centers (RCs) and its transfer further down the photosynthetic electron-transport chain. An additive relationship matrix was estimated based on pedigree reconstruction, utilizing a set of highly polymorphic single sequence repeat markers. Variance decomposition was conducted using the animal genetic evaluation mixed-linear model. The majority of ChlF parameters in the analyzed pine populations showed significant additive genetic variation. Statistically significant heritability estimates were obtained for most ChlF indices, with the exception of DI0/RC, φD0 and φP0 (Fv/Fm) parameters. Estimated heritabilities varied around the value of 0.15 with the maximal value of 0.23 in the ET0/RC parameter, which indicates electron-transport flux from QA to QB per PSII RC. No significant correlation was found between these indices and selected growth traits. Moreover, no genotype × environment interaction (G × E) was detected, i.e., no differences in genotypes' performance between sites. The absence of significant G × E in our study is interesting, given the relatively low heritability found for the majority of parameters analyzed. Therefore, we infer that polygenic variability of these indices is selectively neutral. [ABSTRACT FROM AUTHOR]

We extend the palette of possible colonies models of two different clones of Serratia rubidaea. Our model fits the real morphology of the colonies. We also present that the colony growth leads to a change in the ratio of the fitness which propose to be caused by the production of some signal. This signal influences the behavior of the clones and leads to the prolonged diversity maintenance. The explanation of the diversity maintenance of the mixed concurrent population in one niche is the current studied problem in the ecology and evolution. [ABSTRACT FROM AUTHOR]

Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. [ABSTRACT FROM AUTHOR]

Population dynamics of three different bacterial species, Serratia rubidaea (R), Serratia marcescens (F) and Escherichia coli (Ec), growing in single or mixed populations in liquid media, was monitored by real time headspace quantification of volatile compounds using selected ion flow tube mass spectrometry, SIFT-MS. The three bacterial species interact with each other in a competitive fashion in a way similar to the game “rock-paper-scissors” (R-Ec-F). The concentrations of volatile metabolites (ammonia, ethanol, acetaldehyde, propanol, acetoin, acetone and acetic acid) were measured in the headspace of the individual species and of their mixtures continuously for 24 hour periods. The results demonstrate that dynamics in bacterial cultures can be monitored using SIFT-MS in real time. [ABSTRACT FROM AUTHOR]

Background: Bacteria grown on semi-solid media can build two types of multicellular structures, depending on the circumstances. Bodies (colonies) arise when a single clone is grown axenically (germ-free), whereas multispecies chimeric consortia contain monoclonal microcolonies of participants. Growth of an axenic colony, mutual interactions of colonies, and negotiation of the morphospace in consortial ecosystems are results of intricate regulatory and metabolic networks. Multicellular structures developed by Serratia sp. are characteristically shaped and colored, forming patterns that reflect their growth conditions (in particular medium composition and the presence of other bacteria). Results: Building on our previous work, we developed a model system for studying ontogeny of multicellular bacterial structures formed by five Serratia sp. morphotypes of two species grown in either "germ-free" or "gnotobiotic" settings (i. e. in the presence of bacteria of other conspecific morphotype, other Serratia species, or E. coli). Monoclonal bodies show regular and reproducible macroscopic appearance of the colony, as well as microscopic pattern of its growing margin. Standard development can be modified in a characteristic and reproducible manner in close vicinity of other bacterial structures (or in the presence of their products). Encounters of colonies with neighbors of a different morphotype or species reveal relationships of dominance, cooperation, or submission; multiple interactions can be summarized in "rock--paper--scissors" network of interrelationships. Chimerical (mixed) plantings consisting of two morphotypes usually produced a "consortium" whose structure is consistent with the model derived from interaction patterns observed in colonies. Conclusions: Our results suggest that development of a bacterial colony can be considered analogous to embryogenesis in animals, plants, or fungi: to proceed, early stages require thorough insulation from the rest of the biosphere. Only later, the newly developing body gets connected to the ecological interactions in the biosphere. Mixed "anlagen" cannot accomplish the first, germ-free phase of development; hence, they will result in the consortium of small colonies. To map early development and subsequent interactions with the rest of the biospheric web, simplified gnotobiotic systems described here may turn to be of general use, complementing similar studies on developing multicellular eukaryots under germ-free or gnotobiotic conditions. [ABSTRACT FROM AUTHOR]

Norway spruce has a broad natural distribution range, which results in a substantial variety of its physiological and genetic variation. There are three distinct altitudinal ecotypes described in this tree species. The physiological optimum of each ecotype may be shifted due to ongoing climate change, especially in traits associated with water demand that might be crucial for adaptation. Dehydrins are proteins that help to mitigate the adverse effects of dehydration. Dehydrin gene expression patterns appeared to be a suitable marker for plant stress assessment. Genetically determined differences in response between individuals and populations were formerly studied, however, mainly in controlled conditions. We evaluated ecotypic variation in dehydrin gene expression in a clonal bank comprised of all three ecotypes. A genetic relationship among targeted trees was uncovered utilizing GBS (Genotyping by Sequencing) platform. We sampled 4–6 trees of each ecotype throughout 15 months period. Subsequently, we assessed the RNA expression of dehydrin genes by qRT-PCR. For this study, we deliberately selected dehydrins from different categories. Our findings detected significant differences among ecotypes in dehydrin expression. The association of recorded climatic variables and individual gene expression across the study period was evaluated and revealed, for certain genes, a correlation between dehydrin gene expression and precipitation, temperature, and day-length. [ABSTRACT FROM AUTHOR]

Research Highlights: Although a number of forestry studies have found that hydrogel improves tree performance, studies that are located in semi-arid regions and that include a broad spectrum of tree species and the assessment of multiple physiological traits are lacking. Background and Objectives: The objective of the current study was to evaluate the effects of hydrogel treatments (with sawdust, organic fertilizer, compost, wheat straw, subsoil, or subsoil with a cobble cover) applied during planting on the survival, growth, and physiological traits of 20 tree species. Materials and Methods: In a field experiment (factorial design with seven treatments including a control, 20 species, and ten replicates) in a semi-arid part of Iran, we applied water alone (control) or water with hydrogel and other materials to recently planted samplings. We evaluated tree height, health, osmotic potential, and biochemical properties after 6 months and survival after 12 months. Results: Hydrogel treatment (regardless of other material) significantly improved the performance of drought-sensitive but not of drought-tolerant species. Conclusions: The benefits of hydrogel treatment are substantial for drought-sensitive species but are insignificant for drought-resistant species. [ABSTRACT FROM AUTHOR]

Spontaneous variation in appearance was studied in bacterial colonies ofSerratia marcescensF morphotype1: (i) A defined array of non-heritable phenotype variations does appear repeatedly; (ii) The presence of colonies of different bacterial species will narrow the variability toward the typical F appearance, as if such an added environmental factor curtailed the capacity of colony morphospace; (iii) Similarly the morphospace becomes reduced by random mutations leading to new, heritable morphotypes—at the same time opening a new array of variations typical for the mutant but not accessible directly from the original F morphospace. Results are discussed in context with biphasic model of early morphogenesis applicable to all multicellular bodies. [ABSTRACT FROM PUBLISHER]