Improving our understanding of the potential of forest adaptation is an urgent task in the light of predicted climate change. Long-term alternatives for susceptible yet economically important tree species such as Norway spruce (Picea abies) are required, if the frequency and intensity of summer droughts will continue to increase. Although Silver fir (Abies alba) and Douglas fir (Pseudotsuga menziesii) have both been described as drought-tolerant species, our understanding of their growth responses to drought extremes is still limited. Here, we use a dendroecological approach to assess the resistance, resilience, and recovery of these important central Europe to conifer species the exceptional droughts in 1976 and 2003. A total of 270 trees per species were sampled in 18 managed mixed-species stands along an altitudinal gradient (400-1200 m a.s.l.) at the western slopes of the southern and central Black Forest in southwest Germany. While radial growth in all species responded similarly to the 1976 drought, Norway spruce was least resistant and resilient to the 2003 summer drought. Silver fir showed the overall highest resistance to drought, similarly to Douglas fir, which exhibited the widest growth rings. Silver fir trees from lower elevations were more drought prone than trees at higher elevations. Douglas fir and Norway spruce, however, revealed lower drought resilience at higher altitudes. Although the 1976 and 2003 drought extremes were quite different, Douglas fir maintained consistently the highest radial growth. Although our study did not examine population-level responses, it clearly indicates that Silver fir and Douglas fir are generally more resistant and resilient to previous drought extremes and are therefore suitable alternatives to Norway spruce; Silver fir more so at higher altitudes. Cultivating these species instead of Norway spruce will contribute to maintaining a high level of productivity across many Central European mountain forests under future climate change.

• MeSH
• fyziologická adaptace MeSH
• jedle fyziologie   MeSH
• klimatické změny MeSH
• lesy MeSH
• období sucha * MeSH
• Pseudotsuga fyziologie   MeSH
• smrk fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH
• Německo MeSH
• Norsko MeSH

Silver fir is one of the most productive and ecologically valuable native European tree species, however, it has been experiencing decline which has periodically occurred over its natural range. This paper aims to investigate the recent climate-growth relationships of silver fir (Abies alba Mill.) and its temporal change along the course of its life. Long-term tree-ring databases, as well as records on climate, atmospheric SO2, NO3 and acid concentrations from four different regions in the Western Carpathians were used. The results provide clear evidence of significant increase of silver fir's radial increment over the entire Western Carpathian area since 1970-1980. The results indicated that the most probable factors behind the rapid recovery of tree radial increment were reductions in emissions of NO3 and SO2, alongside a significant increase in mean June, July and April temperatures.

• MeSH
• dusičnany analýza   MeSH
• ekologie MeSH
• jedle růst a vývoj   MeSH
• klimatické změny MeSH
• látky znečišťující vzduch analýza   MeSH
• monitorování životního prostředí MeSH
• oxid siřičitý analýza   MeSH
• podnebí MeSH
• teplota MeSH
• znečištění ovzduší statistika a číselné údaje   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Here, we perform cross-generational GS analysis on coastal Douglas-fir (Pseudotsuga menziesii), reflecting trans-generational selective breeding application. A total of 1321 trees, representing 37 full-sib F1 families from 3 environments in British Columbia, Canada, were used as the training population for (1) EBVs (estimated breeding values) of juvenile height (HTJ) in the F1 generation predicting genomic EBVs of HTJ of 136 individuals in the F2 generation, (2) deregressed EBVs of F1 HTJ predicting deregressed genomic EBVs of F2 HTJ, (3) F1 mature height (HT35) predicting HTJ EBVs in F2, and (4) deregressed F1 HT35 predicting genomic deregressed HTJ EBVs in F2. Ridge regression best linear unbiased predictor (RR-BLUP), generalized ridge regression (GRR), and Bayes-B GS methods were used and compared to pedigree-based (ABLUP) predictions. GS accuracies for scenarios 1 (0.92, 0.91, and 0.91) and 3 (0.57, 0.56, and 0.58) were similar to their ABLUP counterparts (0.92 and 0.60, respectively) (using RR-BLUP, GRR, and Bayes-B). Results using deregressed values fell dramatically for both scenarios 2 and 4 which approached zero in many cases. Cross-generational GS validation of juvenile height in Douglas-fir produced predictive accuracies almost as high as that of ABLUP. Without capturing LD, GS cannot surpass the prediction of ABLUP. Here we tracked pedigree relatedness between training and validation sets. More markers or improved distribution of markers are required to capture LD in Douglas-fir. This is essential for accurate forward selection among siblings as markers that track pedigree are of little use for forward selection of individuals within controlled pollinated families.

• MeSH
• genomika MeSH
• lineární modely MeSH
• modely genetické MeSH
• Pseudotsuga genetika   růst a vývoj   MeSH
• šlechtění rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Britská Kolumbie MeSH

*Increasing evidence about hydraulic redistribution and its ecological consequences is emerging. Hydraulic redistribution results from an interplay between competing plant and soil water potential gradients. In this work, stem-mediated hydraulic redistribution was studied in a 53-year-old Douglas-fir tree during a period of drought. *Sap flux density measurements using the heat field deformation method were performed at four locations: in two large opposing roots and on two sides of the tree stem. Hydraulic redistribution was induced by localized irrigation on one of the measured roots, creating heterogeneous soil water conditions. *Stem-mediated hydraulic redistribution was detected during night-time conditions when water was redistributed from the wet side of the tree to the nonirrigated dry side. In addition to stem-mediated hydraulic redistribution, bidirectional flow in the dry root was observed, indicating radial sectoring in the xylem. *It was observed that, through stem-mediated hydraulic redistribution, Douglas-fir was unable to increase its transpiration despite the fact that sufficient water was available to one part of the root system. This resulted from the strong water potential gradient created by the dry soil in contact with the nonirrigated part of the root system. A mechanism of stem-mediated hydraulic redistribution is proposed and its possible implications are discussed.

• MeSH
• fyziologická adaptace fyziologie   MeSH
• kořeny rostlin fyziologie   MeSH
• období sucha MeSH
• Pseudotsuga fyziologie   MeSH
• půda MeSH
• stonky rostlin fyziologie   MeSH
• stromy fyziologie   MeSH
• transpirace rostlin fyziologie   MeSH
• voda fyziologie   MeSH
• xylém MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Silice z jedle sibiřské (Abies sibirica Ledeb.) patří mezi látky s potenciálním využitím v prevenci a terapii orálních kandidóz. Proto cílem práce byla formulace, příprava a hodnocení orálního gelu obsahujícího 0,3 % této silice. Jako gelotvorná látka byl použit Carbopol 974P NF v 1% koncentraci, řada vzorků byla navíc stabilizována přísadou polysorbátu 80 (0,1–0,5 %). K úpravě chuťových vlastností sloužil xylitol v koncentraci 10 % nebo 20 %. Na základě mikroskopického hodnocení (průměrná velikost kapek silice, stupeň disperzity) ihned po přípravě a po šestiměsíčním uchovávání bylo zjištěno, že optimální koncentrace polysorbátu 80 je 0,3 %. Z výsledků experimentu rovněž vyplývá, že xylitol představuje nejen pomocnou látku upravující organoleptické vlastnosti přípravku, ale jeho použití umožňuje významným způsobem ovlivnit kvalitativní parametry a stabilitu. Klíčová slova: jedle sibiřská • silice • orální gel • xylitol • stabilita

Essential oil of the Siberian fir (Abies sibirica Ledeb.) ranks among the substances with potential use in prevention and treatment of oral candidiasis. Therefore, the aim of the study was the formulation, preparation and evaluation of an oral gel containing 0.3% of this essential oil. Carbopol 974P NF in 1% concentration was used as the gelling agent, some samples were additionally stabilized by an addition of polysorbate 80 (0.1–0.5%). Xylitol in concentrations of 10% or 20% was added with the aim to modify the taste properties of the gel. Following microscopic evaluation (mean oil droplet size, degree of dispersity) immediately after preparation and after 6-month storage, it has been found that the optimal concentration of polysorbate 80 is 0.3%. The results of the experiment also demonstrated that xylitol was not only an excipient adjusting the organoleptic properties of the preparation – its use enabled significant improvement of the quality parameters and stability. Keywords: Siberian fir • essential oil • oral gel • xylitol • stability

• Klíčová slova
• silice, orální gel,
• MeSH
• akryláty MeSH
• gely normy   MeSH
• jedle * MeSH
• lidé MeSH
• oleje prchavé * MeSH
• orální kandidóza * farmakoterapie   prevence a kontrola   MeSH
• polysorbáty MeSH
• pomocné látky MeSH
• příprava léků * metody   statistika a číselné údaje   MeSH
• řízení kvality MeSH
• stabilita léku MeSH
• xylitol * normy   MeSH
• Check Tag
• lidé MeSH

Seed orchards main function is delivering breeding programs' gains in the form of genetically improved seedlings. They are unique experimental populations, perfectly suited for studying various pollination environments (natural or otherwise), affecting their mating system parameters. Here, under different pollination environment (natural and intrusive (pollen augmentation and/or bloom-delay)), the mating system of a second generation, wind-pollinated, coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) seed orchard was evaluated over four years. Using DNA microsatellite markers and bulk seed samples, we conducted pedigree reconstruction to assign each seed's male and female parents, followed by determining the extent of pollen contamination (external gene flow), selfing rate, and, parental gametic contribution for each year. Overall, external pollen contamination rates ranged between 10 and 28%, selfing rate varied between 12 and 17%, and 80% of the seed crops were produced by 37-64% of the orchard's parents. Pollination environment and seed crop size substantially influenced the observed results, particularly for small crops as pollen contamination was high in natural (28%) vs. intrusive pollination (10%). Generally, irrespective of the crop size, seed produced under natural pollination had higher pollen contamination, confirming the role of pollination environment manipulation in improving seed crops' genetic quality.

• MeSH
• mikrosatelitní repetice * MeSH
• opylení fyziologie   MeSH
• Pseudotsuga * genetika   růst a vývoj   MeSH
• pyl * genetika   růst a vývoj   MeSH
• semena rostlinná * genetika   růst a vývoj   MeSH
• šlechtění rostlin * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Abies guatemalensis Rehder, an endangered conifer endemic to Central American highlands, is ecologically vital in upper montane forests. It faces threats from habitat fragmentation, unsustainable logging, and illegal Christmas tree harvesting. While previous genetic studies on mature trees from eighteen populations showed high within-population diversity and limited among-population differentiation, the genetic impact of recent anthropogenic pressures on younger generations has yet to be discovered. Understanding these effects is crucial for developing effective conservation strategies for this vulnerable species. We sampled 170 young trees (< 15 years old) from seven populations across Guatemala. Seven microsatellite markers were used to analyse genetic diversity, population structure, and recent demographic history. Moderate levels of genetic diversity were observed within populations (mean Shannon diversity index = 4.97, mean Simpson's index = 0.51, mean allelic richness = 11.59, mean observed heterozygosity = 0.59). Although genetic structure broadly aligned with mountain corridors, substantial admixture patterns suggest historical connectivity across all populations. Most populations showed evidence of recent bottlenecks (p < 0.05) and inbreeding. The results suggest a potential decline in genetic diversity and increased population structuring (ΦST = 0.274, p < 0.01) over the past decades compared to the previous study on old trees. The observed genetic patterns indicate ongoing impacts of habitat fragmentation and anthropogenic pressures on A. guatemalensis. Conservation efforts should prioritise expanding effective population sizes and facilitating gene flow, particularly for isolated populations. While restoration efforts may be logistically easier within mountain ranges, genetic evidence suggests that increasing overall population connectivity could benefit this species. Management strategies should implement systematic seed collection protocols to maintain genetic diversity in future populations. These findings highlight the urgent need for conservation measures to preserve remaining genetic diversity and promote connectivity among A. guatemalensis populations.

• MeSH
• ekosystém * MeSH
• genetická variace * MeSH
• jedle * genetika   MeSH
• mikrosatelitní repetice * genetika   MeSH
• ohrožené druhy * MeSH
• populační genetika MeSH
• zachování přírodních zdrojů MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Guatemala MeSH

BACKGROUND: Genomic selection (GS) can offer unprecedented gains, in terms of cost efficiency and generation turnover, to forest tree selective breeding; especially for late expressing and low heritability traits. Here, we used: 1) exome capture as a genotyping platform for 1372 Douglas-fir trees representing 37 full-sib families growing on three sites in British Columbia, Canada and 2) height growth and wood density (EBVs), and deregressed estimated breeding values (DEBVs) as phenotypes. Representing models with (EBVs) and without (DEBVs) pedigree structure. Ridge regression best linear unbiased predictor (RR-BLUP) and generalized ridge regression (GRR) were used to assess their predictive accuracies over space (within site, cross-sites, multi-site, and multi-site to single site) and time (age-age/ trait-trait). RESULTS: The RR-BLUP and GRR models produced similar predictive accuracies across the studied traits. Within-site GS prediction accuracies with models trained on EBVs were high (RR-BLUP: 0.79-0.91 and GRR: 0.80-0.91), and were generally similar to the multi-site (RR-BLUP: 0.83-0.91, GRR: 0.83-0.91) and multi-site to single-site predictive accuracies (RR-BLUP: 0.79-0.92, GRR: 0.79-0.92). Cross-site predictions were surprisingly high, with predictive accuracies within a similar range (RR-BLUP: 0.79-0.92, GRR: 0.78-0.91). Height at 12 years was deemed the earliest acceptable age at which accurate predictions can be made concerning future height (age-age) and wood density (trait-trait). Using DEBVs reduced the accuracies of all cross-validation procedures dramatically, indicating that the models were tracking pedigree (family means), rather than marker-QTL LD. CONCLUSIONS: While GS models' prediction accuracies were high, the main driving force was the pedigree tracking rather than LD. It is likely that many more markers are needed to increase the chance of capturing the LD between causal genes and markers.

• MeSH
• dřevo chemie   genetika   MeSH
• exom * MeSH
• genomika MeSH
• genotyp MeSH
• lineární modely MeSH
• lokus kvantitativního znaku MeSH
• modely genetické * MeSH
• Pseudotsuga genetika   růst a vývoj   MeSH
• selekce (genetika) * MeSH
• šlechtění rostlin * MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Publikační typ
• časopisecké články MeSH

Genetic association studies in forest trees would greatly benefit from information on the response of trees to environmental stressors over time, which can be provided by dendroecological analysis. Here, we jointly analysed dendroecological and genetic data of surviving silver fir trees to explore the genetic basis of their response to the iconic stress episode of the 1970s and 1980s that led to large-scale forest dieback in Central Europe and has been attributed to air pollution. Specifically, we derived dendrophenotypic measures from 190 trees in the Bavarian Forest that characterize the resistance, resilience and recovery during this growth depression, and in the drought year in 1976. By focusing on relative growth changes of trees and by standardizing the dendrophenotypes within stands, we accounted for variation introduced by micro- and macroscale environmental differences. We associated the dendrophenotypes with single nucleotide polymorphisms (SNPs) in candidate genes using general linear models (GLMs) and the machine learning algorithm random forest with subsequent feature selection. Most trees at our study sites experienced a severe growth decline from 1974 until the mid-1980s with minimum values during the drought year. Fifteen genes were associated with the dendrophenotypes, including genes linked to photosynthesis and drought stress. With our study, we show that dendrophenotypes can be a powerful resource for genetic association studies that permit to account for micro- and macroenvironmental variation when data are derived from natural populations. We call for a wider collaboration of dendroecologists and forest geneticists to integrate individual tree-level dendrophenotypes in genetic association studies.

• MeSH
• ekologie MeSH
• fyziologická adaptace genetika   MeSH
• fyziologický stres genetika   MeSH
• genetické asociační studie MeSH
• genotyp MeSH
• jedle genetika   růst a vývoj   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• období sucha MeSH
• podnebí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The diet rich in fruits and vegetables reduces the risk of metabolic syndrome, including diabetes development by various mechanisms of action, mainly due to the presence of polyphenolic compounds. Extracts from different conifer species are known to be a rich source of various polyphenols. In the present study we elucidated the in vitro mechanism of anti-diabetic activity of silver fir (Abies alba) wood and bark extracts and compared their activity to non-coniferous sweet chestnut wood extract and standardized maritime pine bark extract. Extracts and lignans were tested for their inhibitory activity of enzymes involved in the regulation of blood glucose in vitro. The ability of extracts to protect against oxidative stress in high glucose environment was tested on mouse myoblast cell line. Silver fir wood and bark extracts were shown to be effective inhibitors of α-glucosidase, α-amylase and dipeptidyl peptidase 4, three enzymes involved in the regulation of blood glucose levels. Coniferous extracts also showed protection against oxidative stress generated in high glucose environment. Lignans, particularly pinoresinol diglucoside, isolariciresinol and secolariciresinol were shown to be important contributors of antihyperglycemic activity through inhibition of dipeptidyl peptidase 4. This corroborates previously published in vivo results on blood glucose level obtained with silver fir wood extract and supports the use of silver fir wood and bark extracts as food supplements or functional foods in borderline diabetes.

• MeSH
• alfa-amylasy antagonisté a inhibitory   MeSH
• alfa-glukosidasy metabolismus   MeSH
• buněčné linie MeSH
• dipeptidylpeptidasa 4 metabolismus   MeSH
• dřevo chemie   MeSH
• hypoglykemika izolace a purifikace   farmakologie   MeSH
• inhibitory dipeptidylpeptidasy 4 izolace a purifikace   farmakologie   MeSH
• inhibitory glykosidových hydrolas izolace a purifikace   farmakologie   MeSH
• jedle chemie   MeSH
• krevní glukóza účinky léků   MeSH
• kůra rostlin chemie   MeSH
• lidé MeSH
• myši MeSH
• oxidační stres účinky léků   MeSH
• rostlinné extrakty izolace a purifikace   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH