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The Science of the Total Environment Dec 2017Even though pedunculate oak (Quercus robur L.) and grayish oak (Quercus pedunculiflora K. Koch) have different ecological requirements, they have been considered as...
Leaf morphological variability and intraspecific taxonomic units for pedunculate oak and grayish oak (genus Quercus L., series Pedunculatae Schwz.) in Southern Carpathian Region (Romania).
Even though pedunculate oak (Quercus robur L.) and grayish oak (Quercus pedunculiflora K. Koch) have different ecological requirements, they have been considered as having low differentiation at the level of morphological traits and genetic variation. The leaf morphology for 862 trees has been assessed in 16 natural populations, seven of Q. robur, eight of Q. pedunculiflora and a mixed forest were both taxa coexist. In total, fifteen descriptors have been analysed by using discriminant analysis, while it was found that with only four out of the fifteen leaf traits (abaxial pubescence, abaxial colour of the leaf, petiole length and basal shape of lamina) the two taxa could be clearly differentiated. A dendrogram has been constructed on the basis of these traits, where the populations of each taxon have been clustered together. PU and CL traits of Q. pedunculiflora were discussed for their adaptive value for drought resistance in the steppe habitats occupied by this taxon. Using the leaves' morphological descriptors and data from the literature, intra-taxonomic units (varieties, forms and sub-forms) have been identified in all analysed populations. Eight intraspecific units for Q. robur and six for Q. pedunculiflora have been identified in the investigated area. An analysis of spatial distribution of the two taxa and of their intraspecific units has been performed using maps of ecoregions for the study area.
Topics: Genetic Variation; Genetics, Population; Plant Leaves; Quercus; Romania; Trees
PubMed: 28755599
DOI: 10.1016/j.scitotenv.2017.05.274 -
Global Change Biology Mar 2020Spring phenology of temperate trees has advanced worldwide in response to global warming. However, increasing temperatures may not necessarily lead to further...
Spring phenology of temperate trees has advanced worldwide in response to global warming. However, increasing temperatures may not necessarily lead to further phenological advance, especially in the warmer latitudes because of insufficient chilling and/or shorter day length. Determining the start of the forcing phase, that is, when buds are able to respond to warmer temperatures in spring, is therefore crucial to predict how phenology will change in the future. In this study, we used 4,056 leaf-out date observations during the period 1969-2017 for clones of European beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.) planted in 63 sites covering a large latitudinal gradient (from Portugal ~41°N to Norway ~63°N) at the International Phenological Gardens in order to (a) evaluate how the sensitivity periods to forcing and chilling have changed with climate warming, and (b) test whether consistent patterns occur along biogeographical gradients, that is, from colder to warmer environments. Partial least squares regressions suggest that the length of the forcing period has been extended over the recent decades with climate warming in the colder latitudes but has been shortened in the warmer latitudes for both species, with a more pronounced shift for beech. We attribute the lengthening of the forcing period in the colder latitudes to earlier opportunities with temperatures that can promote bud development. In contrast, at warmer or oceanic climates, the beginning of the forcing period has been delayed, possibly due to insufficient chilling. However, in spite of a later beginning of the forcing period, spring phenology has continued to advance at these areas due to a faster satisfaction of heat requirements induced by climate warming. Overall, our results support that ongoing climate warming will have different effects on the spring phenology of forest trees across latitudes due to the interactions between chilling, forcing and photoperiod.
Topics: Climate Change; Fagus; Norway; Portugal; Quercus; Seasons; Temperature; Trees
PubMed: 31724292
DOI: 10.1111/gcb.14918 -
Proceedings. Biological Sciences Sep 2020Insects and pathogens frequently exploit the same host plant and can potentially impact each other's performance. However, studies on plant-pathogen-insect interactions...
Insects and pathogens frequently exploit the same host plant and can potentially impact each other's performance. However, studies on plant-pathogen-insect interactions have mainly focused on a fixed temporal setting or on a single interaction partner. In this study, we assessed the impact of time of attacker arrival on the outcome and symmetry of interactions between aphids (), powdery mildew (), and caterpillars () feeding on pedunculate oak, , and explored how single versus multiple attackers affect oak performance. We used a multifactorial greenhouse experiment in which oak seedlings were infected with either zero, one, two, or three attackers, with the order of attacker arrival differing among treatments. The performances of all involved organisms were monitored throughout the experiment. Overall, attackers had a weak and inconsistent impact on plant performance. Interactions between attackers, when present, were asymmetric. For example, aphids performed worse, but powdery mildew performed better, when co-occurring. Order of arrival strongly affected the outcome of interactions, and early attackers modified the strength and direction of interactions between later-arriving attackers. Our study shows that interactions between plant attackers can be asymmetric, time-dependent, and species specific. This is likely to shape the ecology and evolution of plant-pathogen-insect interactions.
Topics: Animals; Aphids; Ascomycota; Host-Pathogen Interactions; Insecta; Plant Diseases; Quercus
PubMed: 32962544
DOI: 10.1098/rspb.2020.1303 -
The Journal of Animal Ecology Nov 2022Climate change has been shown to advance spring phenology, increase the number of insect generations per year (multivoltinism) and increase pathogen infection levels....
Climate change has been shown to advance spring phenology, increase the number of insect generations per year (multivoltinism) and increase pathogen infection levels. However, we lack insights into the effects of plant spring phenology and the biotic environment on the preference and performance of multivoltine herbivores and whether such effects extend into the later part of the growing season. To this aim, we used a multifactorial growth chamber experiment to examine the influence of spring phenology on plant pathogen infection, and how the independent and interactive effects of spring phenology and plant pathogen infection affect the preference and performance of multigenerational attackers (the leaf miner Tischeria ekebladella and the aphid Tuberculatus annulatus) on the pedunculate oak in the early, mid and late parts of the plant growing season. Pathogen infection was highest on late phenology plants, irrespective of whether inoculations were conducted in the early, mid or late season. The leaf miner consistently preferred to oviposit on middle and late phenology plants, as well as healthy plants, during all parts of the growing season, whereas we detected an interactive effect between spring phenology and pathogen infection on the performance of the leaf miner. Aphids preferred healthy, late phenology plants during the early season, healthy plants during the mid season, and middle phenology plants during the late season, whereas aphid performance was consistently higher on healthy plants during all parts of the growing season. Our findings highlight that the impact of spring phenology on pathogen infection and the preference and performance of insect herbivores is not restricted to the early season, but that its imprint is still present - and sometimes equally strong - during the peak and end of the growing season. Plant pathogens generally negatively affected herbivore preference and performance, and modulated the effects of spring phenology. We conclude that spring phenology and pathogen infection are two important factors shaping the preference and performance of multigenerational plant attackers, which is particularly relevant given the current advance in spring phenology, pathogen outbreaks and increase in voltinism with climate change.
Topics: Animals; Seasons; Herbivory; Quercus; Plants; Insecta; Climate Change; Aphids; Temperature; Plant Leaves
PubMed: 36047365
DOI: 10.1111/1365-2656.13804 -
Nanomaterials (Basel, Switzerland) Dec 2021Traditional flame retardants often contain halogens and produce toxic gases when burned. Hence, in this study, low-cost, environmentally friendly compounds that act as...
Traditional flame retardants often contain halogens and produce toxic gases when burned. Hence, in this study, low-cost, environmentally friendly compounds that act as fire retardants are investigated. These materials often contain nanoparticles, from which TiO and SiO are the most promising. In this work, pedunculate oak wood specimens were modified with sodium silicate (NaSiO, i.e., water glass) and TiO, SiO, and ZnO nanoparticles using the vacuum-pressure technique. Changes in the samples and fire characteristics of modified wood were studied via thermal analysis (TA), infrared spectroscopy (FTIR), and scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). The results of TA showed the most significant wood decomposition at a temperature of 350 °C, with a non-significant influence of the nanoparticles. A dominant effect of sodium silicate was observed in the main weight-loss step, resulting in a drop in decomposition temperature within the temperature range of 36-44 °C. More intensive decomposition of wood treated with water glass and nanoparticles led to a faster release of non-combustible gases, which slowed down the combustion process. The results demonstrated that wood modifications using sodium silicate and nanoparticle systems have potentially enhanced flame retardant properties.
PubMed: 34947756
DOI: 10.3390/nano11123405 -
Plants (Basel, Switzerland) Feb 2023Oak powdery mildew caused by (Griffon and Maubl.; U. Braun & S. Takam.) is a common disease in European forests. One of the most susceptible species is the pedunculate...
Oak powdery mildew caused by (Griffon and Maubl.; U. Braun & S. Takam.) is a common disease in European forests. One of the most susceptible species is the pedunculate oak ( L.). Presently, a few methods are available to control powdery mildew, e.g., the use of fungicides (e.g., based on citric acid), antagonistic fungi or bacteria, chemical treatments (e.g., sulphur, potassium bicarbonate) or genetic resistance. In our study, we aimed to check the effects of using chitosan derivatives and novel active substances inducing the plants' natural resistance: benzodiathiadiazole (both in neutral and salt form). 84 pedunculate oak seedlings were subjected to the experiment in three treatment variants (plus positive and negative controls). The plants were treated with active substances and inoculated with . Although the powdery mildew symptoms appeared in all variants, they were manifested mainly by the in the form of small spots. The experiment indicated that the highest limitation of powdery mildew was achieved by applying -methyl--methoxyamide-7-carboxybenzo(1,2,3)thiadiazole (BTHWA). The application of BTHWA reduced disease development by 88.9% when compared to the effects of the other variants.
PubMed: 36771718
DOI: 10.3390/plants12030635 -
Database : the Journal of Biological... Nov 2022The degree to which roots elongate is determined by the expression of genes that regulate root growth in each developmental zone of a root. Most studies have, however,...
The degree to which roots elongate is determined by the expression of genes that regulate root growth in each developmental zone of a root. Most studies have, however, focused on the molecular factors that regulate primary root growth in annual plants. In contrast, the relationship between gene expression and a specific pattern of taproot development and growth in trees is poorly understood. However, the presence of a deeply located taproot, with branching lateral roots, can especially mitigate the effect of insufficient water availability in long-lived trees, such as pedunculated oak. In the present article, we integrated the ribonucleic acid (RNA) sequencing data on roots of oak trees into a single comprehensive database, named OakRootRNADB that contains information on both coding and noncoding RNAs. The sequences in the database also enclose information pertaining to transcription factors, transcriptional regulators and chromatin regulators, as well as a prediction of the cellular localization of a transcript. OakRootRNADB has a user-friendly interface and functional tools that increase access to genomic information. Integrated knowledge of molecular patterns of expression, specifically occurring within and between root zones and within root types, can elucidate the molecular mechanisms regulating taproot growth and enhanced root soil exploration. Database URL https://oakrootrnadb.idpan.poznan.pl/.
Topics: Quercus; RNA; RNA-Seq; Plant Roots; Trees
PubMed: 36394419
DOI: 10.1093/database/baac097 -
Ecology and Evolution Mar 2022Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood....
Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak ( L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.
PubMed: 35342614
DOI: 10.1002/ece3.8709 -
Scientific Reports Apr 2018Both plant neighbourhood composition and drought have well-known independent effects on insect herbivore performance, but their interactive effects remain elusive. In...
Both plant neighbourhood composition and drought have well-known independent effects on insect herbivore performance, but their interactive effects remain elusive. In this study we performed a laboratory experiment to investigate the independent and combined effects of plant neighbourhood composition and drought on the performance of Gypsy moth larvae (Lymantria dispar) feeding on silver birch (Betula pendula) leaves. For this, we collected leaf samples from birch trees growing in a field experiment where we manipulated both host-tree species diversity (three levels: birch monocultures, two-species mixtures associating birch with the pedunculate oak Quercus robur or maritime pine Pinus pinaster, and three-species mixture with pedunculate oak, the maritime pine and birch) and water availability (two levels: irrigated vs. non-irrigated). In most cases, plant neighbourhood composition and irrigation treatments independently and interactively affected herbivore performance traits, especially those related to growth and food (i.e. birch leaves) processing. By addressing the interactive effects of tree species diversity and drought on insect herbivory from the herbivore's point of view, our study builds toward a better understanding of the multiple ecological drivers of plant-insect interactions.
Topics: Animals; Betula; Droughts; Feeding Behavior; Herbivory; Humans; Larva; Moths; Plant Leaves; Trees; Water
PubMed: 29651050
DOI: 10.1038/s41598-018-24299-x -
Endoscopy Nov 2022
Topics: Humans; Esophageal Neoplasms; Endoscopy; Endoscopy, Gastrointestinal; Ligation
PubMed: 35168273
DOI: 10.1055/a-1662-3738