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Agricultural and Forest Meteorology Aug 2020We explored the inter-individual variability in bud-burst and its potential drivers, in homogeneous mature stands of temperate deciduous trees. Phenological observations...
We explored the inter-individual variability in bud-burst and its potential drivers, in homogeneous mature stands of temperate deciduous trees. Phenological observations of leaves and wood formation were performed weekly from summer 2017 to summer 2018 for pedunculate oak, European beech and silver birch in Belgium. The variability of bud-burst was correlated to previous' year autumn phenology (i.e. the onset of leaf senescence and the cessation of wood formation) and tree size but with important differences among species. In fact, variability of bud-burst was primarily related to onset of leaf senescence, cessation of wood formation and tree height for oak, beech and birch, respectively. The inter-individual variability of onset of leaf senescence was not related to the tree characteristics considered and was much larger than the inter-individual variability in bud-burst. Multi-species multivariate models could explain up to 66% of the bud-burst variability. These findings represent an important advance in our fundamental understanding and modelling of phenology and tree functioning of deciduous tree species.
PubMed: 32817727
DOI: 10.1016/j.agrformet.2020.108031 -
Molecular Ecology Jul 2020Populations residing near species' low-latitude range margins (LLMs) often occur in warmer and drier environments than those in the core range. Thus, their genetic...
Candidate gene SNP variation in floodplain populations of pedunculate oak (Quercus robur L.) near the species' southern range margin: Weak differentiation yet distinct associations with water availability.
Populations residing near species' low-latitude range margins (LLMs) often occur in warmer and drier environments than those in the core range. Thus, their genetic composition could be shaped by climatic drivers that differ from those occurring at higher latitudes, resulting in potentially adaptive variants of conservation value. Such variants could facilitate the adaptation of populations from other portions of the geographical range to similar future conditions anticipated under ongoing climate change. However, very few studies have assessed standing genetic variation at potentially adaptive loci in natural LLM populations. We investigated standing genetic variation at single nucleotide polymorphisms (SNPs) located within 117 candidate genes and its links to putative climatic selection pressures across 19 pedunculate oak (Quercus robur L.) populations distributed along a regional climatic gradient near the species' southern range margin in southeastern Europe. These populations are restricted to floodplain forests along large lowland rivers, whose hydric regime is undergoing significant shifts under modern rapid climate change. The populations showed very weak geographical structure, suggesting extensive genetic connectivity and gene flow or shared ancestry. We identified eight (6.2%) positive F -outlier loci, and genotype-environment association analyses revealed consistent associations between SNP allele frequencies and several climatic variables linked to water availability. A total of 61 associations involving 37 SNPs (28.5%) from 35 annotated genes provided important insights into putative functional mechanisms in our system. Our findings provide empirical support for the role of LLM populations as sources of potentially adaptive variation that could enhance species' resilience to climate change-related pressures.
Topics: Europe; Gene Frequency; Genetics, Population; Polymorphism, Single Nucleotide; Quercus; Water
PubMed: 32567080
DOI: 10.1111/mec.15492 -
PhytoKeys 2020is described from northern Chile. The new species is morphologically similar to the discoid caespitose Andean species and belongs to the subgroup displaying yellow...
is described from northern Chile. The new species is morphologically similar to the discoid caespitose Andean species and belongs to the subgroup displaying yellow corollas and yellowish anthers and style branches. It is characterized by a weak, not self-supporting stem, narrowly linear leaves, long pedunculate capitula with (17-)21 involucral bracts, and minutely papillose achenes. Among other characters, the color of the corollas, anthers, and style branches and the number of involucral bracts differentiate it from , which is the morphologically closest species. The new species thrives in the desertic Puna ecoregion and grows amongst tufts of (Poaceae). Detailed pictures of living plants are provided, as well as a distribution map and a dichotomous key to the discoid caespitose species from northern Chile.
PubMed: 32549746
DOI: 10.3897/phytokeys.149.52297 -
Annals of Botany Oct 2020Highly controlled experiments document that plant genetic diversity and relatedness can shape herbivore communities and patterns of herbivory. Evidence from the field...
BACKGROUND AND AIMS
Highly controlled experiments document that plant genetic diversity and relatedness can shape herbivore communities and patterns of herbivory. Evidence from the field is, however, scarce and inconsistent. We assessed whether a genetic signal underlying herbivory can be detected in oak woodlands when accounting for variation at smaller (within-tree) and larger (among-stand) scales.
METHODS
We tested relationships between tree genetic relatedness, leaf chemical defences and insect herbivory for different canopy layers in 240 trees from 15 pedunculate oak (Quercus robur) forest stands. We partitioned sources of variability in herbivory and defences among stands, individuals and branches.
KEY RESULTS
Leaf defences, insect herbivory and their relationship differed systematically between the upper and the lower tree canopy. When accounting for this canopy effect, the variation explained by tree genetic relatedness rose from 2.8 to 34.1 % for herbivory and from 7.1 to 13.8 % for leaf defences. The effect was driven by markedly stronger relationships in the upper canopy.
CONCLUSIONS
Our findings illustrate that considerable effects of the host plant genotype on levels of leaf chemical defences and associated insect herbivory can be detected in natural tree populations when within-individual variation is properly accounted for.
Topics: Animals; Herbivory; Insecta; Plant Leaves; Quercus; Trees
PubMed: 32463869
DOI: 10.1093/aob/mcaa101 -
Journal of Natural Products May 2020Six new triterpenoids (-), two known genins ( and ), and five known functionalized triterpenoids (-) were isolated from a heartwood extract. The purification protocol...
Six new triterpenoids (-), two known genins ( and ), and five known functionalized triterpenoids (-) were isolated from a heartwood extract. The purification protocol was guided by LC-HRMS by searching for structural analogues of bartogenic acid on the basis of their putative empirical formula. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in water and in a non-oaked white wine on the pure compounds - at 5 mg/L. All molecules were perceived as bitter in water and wine, but they were mostly reported as modifying the wine taste balance. Using LC-HRMS, compounds - were observed in oaked red wine and cognac and were semiquantified in oak wood extracts. The influence of two cooperage parameters, oak species and toasting process, on compounds - content was studied. All compounds were found in quantities significantly higher in pedunculate than in sessile oak wood. Toasting is a key step in barrel manufacture and modulates the concentration of the discussed compounds. Significantly higher quantities were observed in untoasted wood compared to medium or highly toasted wood. These findings provide new insights into the molecular origin of taste changes due to oak aging.
Topics: Magnetic Resonance Spectroscopy; Molecular Structure; Quercus; Taste; Triterpenes; Wine; Wood
PubMed: 32343138
DOI: 10.1021/acs.jnatprod.0c00106 -
International Journal of Molecular... Apr 2020Adhesive secretion has a fundamental role in barnacles' survival, keeping them in an adequate position on the substrate under a variety of hydrologic regimes. It arouses...
Adhesive secretion has a fundamental role in barnacles' survival, keeping them in an adequate position on the substrate under a variety of hydrologic regimes. It arouses special interest for industrial applications, such as antifouling strategies, underwater industrial and surgical glues, and dental composites. This study was focused on the goose barnacle adhesion system, a species that lives in the Eastern Atlantic strongly exposed intertidal rocky shores and cliffs. The protein composition of cement multicomplex and cement gland was quantitatively studied using a label-free LC-MS high-throughput proteomic analysis, searched against a custom transcriptome-derived database. Overall, 11,755 peptide sequences were identified in the gland while 2880 peptide sequences were detected in the cement, clustered in 1616 and 1568 protein groups, respectively. The gland proteome was dominated by proteins of the muscle, cytoskeleton, and some uncharacterized proteins, while the cement was, for the first time, reported to be composed by nearly 50% of proteins that are not canonical cement proteins, mainly unannotated proteins, chemical cues, and protease inhibitors, among others. Bulk adhesive proteins accounted for one-third of the cement proteome, with CP52k being the most abundant. Some unannotated proteins highly expressed in the proteomes, as well as at the transcriptomic level, showed similar physicochemical properties to the known surface-coupling barnacle adhesive proteins while the function of the others remains to be discovered. New quantitative and qualitative clues are provided to understand the diversity and function of proteins in the cement of stalked barnacles, contributing to the whole adhesion model in Cirripedia.
Topics: Animals; Cell Adhesion Molecules; Exocrine Glands; Proteome; Thoracica
PubMed: 32260514
DOI: 10.3390/ijms21072524 -
Systematic Parasitology Apr 2020The new species Crinoniscus stroembergi n. sp. belonging to the parasitic isopod family Crinoniscidae Bonnier, 1900, is described from a pedunculate barnacle host...
A new species of Crinoniscus Pérez, 1900 (Crustacea: Isopoda: Crinoniscidae) parasitising the pedunculate barnacle Heteralepas newmani Buhl-Mortensen & Mifsud (Cirripedia: Heteralepadidae) with notes on its ecology and a review of the genus.
The new species Crinoniscus stroembergi n. sp. belonging to the parasitic isopod family Crinoniscidae Bonnier, 1900, is described from a pedunculate barnacle host collected in the Mediterranean Sea. This is the first species of Crinoniscus Pérez, 1900 described from a host in the genus Heteralepas Pilsbry. The male cryptoniscus larva is distinguished from congeneric species by having a dorsoventrally flattened body with the posterolateral margins of the cephalon scarcely extending beyond the anterior margin of pereomere 1 (in contrast to C. cephalatus Hosie, 2008 with extended margins); articles 1 and 2 of the antennule being subequal in width and the anterodistal angle of antennule article being low and rounded; propodus of pereopods 6 and 7 having a sinuous dorsal margin that is distally narrowing and the posterior margin of the pleotelson being short and rounded. The mature females of species in Crinoniscus are of two basic forms: those with ventrolateral lobes on the pereomeres (C. alepadis (Gruvel, 1901) n. comb., and C. politosummus Hosie, 2008) and those lacking such lobes (C. cephalatus and C. stroembergi n. sp.). The mature females of C. stroembergi n. sp. can be distinguished from other species of Crininiscus based on their lacking lobes on the anterior end. The material examined includes the male and three female developmental stages of the parasite in the host, Heteralepas newmani Buhl-Mortensen & Mifsud. The mouthparts of the immature female are described and the feeding biology and effects on the host are discussed along with a review of feeding modes in species of the Cryptoniscoidea. Leponiscus alepadis is transferred to Crinoniscus; the latter genus now contains five species. A modified diagnosis of Crinoniscus is provided.
Topics: Animals; Female; Isopoda; Male; Mediterranean Sea; Species Specificity; Thoracica
PubMed: 32065370
DOI: 10.1007/s11230-020-09903-x -
Taiwanese Journal of Obstetrics &... Jan 2020To evaluate differences in hysteroscopic findings between benign endometrial polyps and endometrial cancer.
OBJECTIVE
To evaluate differences in hysteroscopic findings between benign endometrial polyps and endometrial cancer.
MATERIALS AND METHODS
From January 2012 to December 2016, we extracted 179 cases with endometrial polyps from 3066 women who underwent hysteroscopy followed by dilatation and curettage or transcervical resection, with 154 and 25 cases of benign and malignant endometrial polyps, respectively. Clinical characteristics, histopathological and hysteroscopic findings of the women were evaluated retrospectively.
RESULTS
The hysteroscopic findings of malignant polyps were hyper-vascular (72%, 18/25), ulcerative (64%, 16/25) and polyps with irregular surfaces (24%, 6/25). In contrast, pedunculate small growths with smooth surfaces were usually seen in the benign endometrial polyps (38.3%, 59/154). Hyper-vascular (OR: 142.6, 95% CI: 25.98-783.4) and polyps with irregular surfaces (OR: 12.02, 95% CI: 1.765-81.83) in hysteroscopic findings were significant strong predictors of endometrial polyps with endometrial cancer. Hysteroscopic findings of ulcerative changes were most strongly associated with a diagnosis of malignant polyps, with sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of 64.0%, 100%, 94.5%, and 100%, respectively.
CONCLUSION
Women with hysteroscopic findings of endometrial polyps with hyper-vascular, ulcerative, and polyps with irregular surfaces had a high likelihood of endometrial cancer. A target biopsy of the polyps with these specific appearances should be performed to exclude malignant lesions.
Topics: Adult; Biopsy; Diagnosis, Differential; Dilatation and Curettage; Endometrial Neoplasms; Endometrium; Female; Humans; Hysteroscopy; Middle Aged; Polyps; Retrospective Studies; Sensitivity and Specificity; Uterine Diseases
PubMed: 32039807
DOI: 10.1016/j.tjog.2019.11.013 -
International Journal of Systematic and... Jan 2020
PubMed: 32019663
DOI: 10.1099/ijsem.0.003940 -
Royal Society Open Science Nov 2019The origin of the arthropod carapace, an enlargement of cephalic tergites, can be traced back to the Cambrian period. However, its disparity and evolution are still not...
The origin of the arthropod carapace, an enlargement of cephalic tergites, can be traced back to the Cambrian period. However, its disparity and evolution are still not fully understood. Here, we describe a new 'bivalved' arthropod, gen. et sp. nov., based on 102 specimens from the middle Cambrian (Wuliuan Stage) Burgess Shale, Marble Canyon area in British Columbia's Kootenay National Park, Canada. The laterally compressed carapace covers most of the body. It is fused dorsally and merges anteriorly into a conspicuous postero-ventrally recurved rostrum as long as the carapace and positioned between a pair of backwards-facing pedunculate eyes. The body is homonomous, with approximately 40 weakly sclerotized segments bearing biramous legs with elongate endopods, and ends in a pair of small flap-like caudal rami. is interpreted as a suspension feeder possibly swimming inverted, in a potential case of convergence with some branchiopods. A Bayesian phylogenetic analysis places it within a group closely related to the extinct Hymenocarina. is unique in its carapace morphology and overall widens the ecological disparity of Cambrian arthropods and suggests that the evolution of a 'bivalved' carapace and an upside-down lifestyle may have occurred early in stem-group crustaceans.
PubMed: 31827867
DOI: 10.1098/rsos.191350