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Beln Corallo Sofia Simeto Gonzalo Martínez Demian Gmez Eduardo Abreo Nora Altier Sandra Lupo 《Journal of Applied Entomology》2019,143(5):542-555
Thaumastocoris peregrinus Carpintero & Dellapé (Heteroptera: Thaumastocoridae) is a sap‐sucking insect that feeds on leaves of Eucalyptus. In Uruguay, it was detected in 2008 causing significant economic losses in Eucalyptus plantations. At present, there is no efficient control for this pest; thus, the use of biological control agents seems to be an environmentally friendly alternative to reduce the damage caused by this insect. The aims of this study were to isolate and identify the species of entomopathogenic fungi that naturally infect T. peregrinus in Uruguay and to characterize and select the most virulent isolates towards this pest. Individuals of T. peregrinus were collected in eight Eucalyptus plantations infested by the pest. The entomopathogenic fungi were isolated and identified by observation of their micromorphological characteristics, and their identity was confirmed by molecular methods. The pathogenicity and virulence against T. peregrinus of the isolated entomopathogenic fungi were evaluated. Isolates causing the highest insect mortality were selected to evaluate the effect of temperature and water activity on conidial viability. Entomopathogenic fungi were found in very low number with the prevalence of less than 3%. Isolates corresponded to Beauveria, Fusarium, Isaria, Lecanicillium, Paecilomyces, Pochonia, Purpureocillium and Simplicillium genera. Two species, B. pseudobassiana and L. muscarium, were first recorded in Uruguay. Among all the tested species, an isolate of B. bassiana (FI 2403) showed the highest virulence followed by an isolate of B. pseudobassiana. The isolate of B. bassiana presented the highest percentage of spore germination at the three temperatures and the highest viability at low water activities. Isolate FI 2403 was selected as a promissory candidate for the development of a commercial formulation against T. peregrinus. 相似文献
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Sally A. Kenny Andrew F. Bennett Michael F. Clarke John W. Morgan 《Austral ecology》2018,43(4):456-469
How does time‐since‐fire influence the structural recovery of semi‐arid, eucalypt‐dominated Murray‐Mallee shrublands after fire, and is recovery affected by spatial variation in climate? We assessed the structure and dynamics of a hummock grass, Triodia scariosa N.T. Burb, and mallee eucalypts – two key structural components of mallee shrublands – using a >100 year time‐since‐fire chronosequence. The relative influence of climatic variables, both individually and combined with time‐since‐fire, was modelled to account for spatial variation in the recovery of vegetation structural components. Time‐since‐fire was the primary determinant of the structural recovery of T. scariosa and eucalypts. However, climate, notably mean annual rainfall and rainfall variability, also influenced the recovery of the eucalypt overstorey, T. scariosa cover and mean hummock height. We observed that (i) the mean number of live eucalypt stems per individual decreased while mean individual basal area increased, (ii) cover of T. scariosa peaked at ~30 years post‐fire and gradually decreased thereafter, and (iii) the ‘hummock’ form of T. scariosa occurred throughout the chronosequence, whereas the ‘ring’ form tended not to occur until ~30 years post‐fire. Time‐since‐fire was the key determinant of the structural recovery of eucalypt‐dominated mallee shrublands, but there is geographical variation in recovery related to rainfall and its variability. Fire regimes are likely to have different effects across the geographic range of mallee shrublands. 相似文献
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GuoQing Li Roger J. Arnold FeiFei Liu JieQiong Li ShuaiFei Chen 《Journal of Phytopathology》2015,163(11-12):956-967
Species of Lasiodiplodia are important pathogens of a wide variety of plants covering a wide geographical distribution. These fungi can be associated with different symptoms such as stem cankers, shoot blights, fruit rots, dieback and gummosis. Diseases caused by Lasiodiplodia were surveyed on Eucalyptus urophylla × grandis, Polyscias balfouriana and Bougainvillea spectabilis in a nursery in southern China. Based on morphology characteristics and phylogenetic analyses of ITS rDNA sequences and translation elongation factor 1‐alpha (TEF‐1α) gene regions, four species of Lasiodiplodia were identified. Lasiodiplodia theobromae was identified from E. urophylla × grandis, P. balfouriana and B. spectabilis. L. hormozganensis, L. iraniensis and L. pseudotheobromae were identified from B. spectabilis. To our knowledge, with the exception of L. theobromae on E. urophylla × grandis, this study represents the first report of these fungi on the host plants. Pathogenicity tests showed that all Lasiodiplodia spp. obtained in this study are virulent to E. urophylla × grandis and B. spectabilis, and L. theobromae was virulent to P. balfouriana. 相似文献
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Understanding the direct and indirect effects of elevated [CO2] and temperature on insect herbivores and how these factors interact are essential to predict ecosystem‐level responses to climate change scenarios. In three concurrent glasshouse experiments, we measured both the individual and interactive effects of elevated [CO2] and temperature on foliar quality. We also assessed the interactions between their direct and plant‐mediated effects on the development of an insect herbivore of eucalypts. Eucalyptus tereticornis saplings were grown at ambient or elevated [CO2] (400 and 650 μmol mol?1 respectively) and ambient or elevated ( + 4 °C) temperature for 10 months. Doratifera quadriguttata (Lepidoptera: Limacodidae) larvae were feeding directly on these trees, on their excised leaves in a separate glasshouse, or on excised field‐grown leaves within the temperature and [CO2] controlled glasshouse. To allow insect gender to be determined and to ensure that any sex‐specific developmental differences could be distinguished from treatment effects, insect development time and consumption were measured from egg hatch to pupation. No direct [CO2] effects on insects were observed. Elevated temperature accelerated larval development, but did not affect leaf consumption. Elevated [CO2] and temperature independently reduced foliar quality, slowing larval development and increasing consumption. Simultaneously increasing both [CO2] and temperature reduced these shifts in foliar quality, and negative effects on larval performance were subsequently ameliorated. Negative nutritional effects of elevated [CO2] and temperature were also independently outweighed by the direct positive effect of elevated temperature on larvae. Rising [CO2] and temperature are thus predicted to have interactive effects on foliar quality that affect eucalypt‐feeding insects. However, the ecological consequences of these interactions will depend on the magnitude of concurrent temperature rise and its direct effects on insect physiology and feeding behaviour. 相似文献
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Qingzhang Du Xiaohui Yang Jianbo Xie Mingyang Quan Liang Xiao Wenjie Lu Jiaxing Tian Chenrui Gong Jinhui Chen Bailian Li Deqiang Zhang 《Plant biotechnology journal》2019,17(3):608-624
In perennial woody plants, the coordinated increase of stem height and diameter during juvenile growth improves competitiveness (i.e. access to light); however, the factors underlying variation in stem growth remain unknown in trees. Here, we used linkage‐linkage disequilibrium (linkage‐LD) mapping to decipher the genetic architecture underlying three growth traits during juvenile stem growth. We used two Populus populations: a linkage mapping population comprising a full‐sib family of 1,200 progeny and an association mapping panel comprising 435 unrelated individuals from nearly the entire natural range of Populus tomentosa. We mapped 311 quantitative trait loci (QTL) for three growth traits at 12 timepoints to 42 regions in 17 linkage groups. Of these, 28 regions encompassing 233 QTL were annotated as 27 segmental homology regions (SHRs). Using SNPs identified by whole‐genome re‐sequencing of the 435‐member association mapping panel, we identified significant SNPs (P ≤ 9.4 × 10?7) within 27 SHRs that affect stem growth at nine timepoints with diverse additive and dominance patterns, and these SNPs exhibited complex allelic epistasis over the juvenile growth period. Nineteen genes linked to potential causative alleles that have time‐specific or pleiotropic effects, and mostly overlapped with significant signatures of selection within SHRs between climatic regions represented by the association mapping panel. Five genes with potential time‐specific effects showed species‐specific temporal expression profiles during the juvenile stages of stem growth in five representative Populus species. Our observations revealed the importance of considering temporal genetic basis of complex traits, which will facilitate the molecular design of tree ideotypes. 相似文献
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ke Berg Karin Ahrn Erik
ckinger Roger Svensson Jrgen Wissman 《Insect Conservation and Diversity》2013,6(6):639-657
- The aim of this study was to compare the butterfly assemblages in semi‐natural pastures and power‐line corridors and to analyse the effects of vegetation height, occurrence of trees and shrubs and different flowering vascular plant groups on butterfly diversity and abundance.
- Twelve of 26 analysed butterfly species were more abundant in power‐line corridors than in semi‐natural pastures. Only one species preferred semi‐natural pastures.
- In semi‐natural pastures butterflies were most common in segments with tall vegetation, whereas butterflies in power‐line corridors were most common in segments with vegetation of short or intermediate height. Short vegetation was sparser in power‐line corridors (mean cover 4%) than in semi‐natural pastures (33%), whereas tall vegetation was more common in power‐line corridors (59%) than in semi‐natural pastures (35%).
- The amount of flowers was the factor that affected the abundance of most species. Twenty‐one of the 26 species showed positive associations with numbers of flowers of different families.
- Flowers of the plant families Apiaceae, Caryophyllaceae, Primulaceae, Rubiaceae, Scrophulariaceae, and Violaceae showed positive associations with the abundance of several butterfly species.
- Vegetation height seems to be a limiting factor in semi‐natural pastures, and less intensive management (division of pastures into grazing pens, late season grazing, grazing every second year, or reduced grazing pressure) would benefit butterflies. In power‐line corridors (dominated by tall vegetation) the opposite would be beneficial for butterflies, for example more frequent clearing of vegetation along the power‐line trails combined with mowing of selected areas.
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John E. Drake Catriona A. Macdonald Mark G. Tjoelker Kristine Y. Crous Teresa E. Gimeno Brajesh K. Singh Peter B. Reich Ian C. Anderson David S. Ellsworth 《Global Change Biology》2016,22(1):380-390
Projections of future climate are highly sensitive to uncertainties regarding carbon (C) uptake and storage by terrestrial ecosystems. The Eucalyptus Free‐Air CO2 Enrichment (EucFACE) experiment was established to study the effects of elevated atmospheric CO2 concentrations (eCO2) on a native mature eucalypt woodland with low fertility soils in southeast Australia. In contrast to other FACE experiments, the concentration of CO2 at EucFACE was increased gradually in steps above ambient (+0, 30, 60, 90, 120, and 150 ppm CO2 above ambient of ~400 ppm), with each step lasting approximately 5 weeks. This provided a unique opportunity to study the short‐term (weeks to months) response of C cycle flux components to eCO2 across a range of CO2 concentrations in an intact ecosystem. Soil CO2 efflux (i.e., soil respiration or Rsoil) increased in response to initial enrichment (e.g., +30 and +60 ppm CO2) but did not continue to increase as the CO2 enrichment was stepped up to higher concentrations. Light‐saturated photosynthesis of canopy leaves (Asat) also showed similar stimulation by elevated CO2 at +60 ppm as at +150 ppm CO2. The lack of significant effects of eCO2 on soil moisture, microbial biomass, or activity suggests that the increase in Rsoil likely reflected increased root and rhizosphere respiration rather than increased microbial decomposition of soil organic matter. This rapid increase in Rsoil suggests that under eCO2, additional photosynthate was produced, transported belowground, and respired. The consequences of this increased belowground activity and whether it is sustained through time in mature ecosystems under eCO2 are a priority for future research. 相似文献
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Patrick S. Fahey Rachael M. Fowler Todd G. B. McLay Frank Udovicic David J. Cantrill Michael J. Bayly 《Ecology and evolution》2021,11(1):664-678
AimTo infer relationships between populations of the semi‐arid, mallee eucalypt, Eucalyptus behriana, to build hypotheses regarding evolution of major disjunctions in the species'' distribution and to expand understanding of the biogeographical history of southeastern Australia.LocationSoutheastern Australia.Taxon Eucalyptus behriana (Myrtaceae, Angiospermae).MethodsWe developed a large dataset of anonymous genomic loci for 97 samples from 11 populations of E. behriana using double digest restriction site‐associated DNA sequencing (ddRAD‐seq), to determine genetic relationships between the populations. These relationships, along with species distribution models, were used to construct hypotheses regarding environmental processes that have driven fragmentation of the species’ distribution.ResultsGreatest genetic divergence was between populations on either side of the Lower Murray Basin. Populations west of the Basin showed greater genetic divergence between one another than the eastern populations. The most genetically distinct population in the east (Long Forest) was separated from others by the Great Dividing Range. A close relationship was found between the outlying northernmost population (near West Wyalong) and those in the Victorian Goldfields despite a large disjunction between them.ConclusionsPatterns of genetic variation are consistent with a history of vicariant differentiation of disjunct populations. We infer that an early disjunction to develop in the species distribution was that across the Lower Murray Basin, an important biogeographical barrier separating many dry sclerophyll plant taxa in southeastern Australia. Additionally, our results suggest that the western populations fragmented earlier than the eastern ones. Fragmentation, both west and east of the Murray Basin, is likely tied to climatic changes associated with glacial‐interglacial cycles although it remains possible that major geological events including uplift of the Mount Lofty Ranges and basalt flows in the Newer Volcanics Province also played a role. 相似文献
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Mit mutations that disrupt function of the mitochondrial electron transport chain can, inexplicably, prolong Caenorhabditis elegans lifespan. In this study we use a metabolomics approach to identify an ensemble of mitochondrial‐derived α‐ketoacids and α‐hydroxyacids that are produced by long‐lived Mit mutants but not by other long‐lived mutants or by short‐lived mitochondrial mutants. We show that accumulation of these compounds is dependent on concerted inhibition of three α‐ketoacid dehydrogenases that share dihydrolipoamide dehydrogenase (DLD) as a common subunit, a protein previously linked in humans with increased risk of Alzheimer's disease. When the expression of DLD in wild‐type animals was reduced using RNA interference we observed an unprecedented effect on lifespan – as RNAi dosage was increased lifespan was significantly shortened, but, at higher doses, it was significantly lengthened, suggesting that DLD plays a unique role in modulating length of life. Our findings provide novel insight into the origin of the Mit phenotype. 相似文献
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Murray V. Ellis Jennifer E. Taylor Laura Rayner 《Ecological Management & Restoration》2015,16(2):114-123
Hollows, also known as tree cavities, are critical to the survival of many animal species but are too poorly mapped across landscapes to allow for their adequate consideration in regional planning. Managing cost is important, so we tested whether freely available satellite‐derived foliage projective cover and field‐measured stand attributes could be used separately or combined to predict tree hollow abundance in relictual Australian temperate woodlands. Satellite‐derived foliage projective cover revealed variation in woody vegetation densities both within mapped woodland remnants and cleared areas of the agricultural matrix. Plot‐based field assessment of the actual number of hollows in each one‐hectare site (n = 110 sites) revealed a relationship with foliage cover. Improvement of the model was achieved if site‐based estimates of the proportion of the canopy due to Eucalyptus species and the number of mature trees per hectare were included. Remotely sensed foliage cover can improve on traditional vegetation mapping for predicting hollow‐bearing tree and hollow abundances at landscape scales when managing hollow‐dependent fauna habitat across relictual woodlands in temperate Australian agricultural landscapes. At finer scales, the addition of other predictors is necessary to raise the accuracy of the predicted hollow densities. 相似文献
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E. N. Bui A. H. Thornhill C. E. González‐Orozco N. Knerr J. T. Miller 《Geobiology》2017,15(3):427-440
Eucalypts cover most of Australia. Here, we investigate the relative contribution of climate and geochemistry to the distribution and diversity of eucalypts. Using geostatistics, we estimate major element concentrations, pH, and electrical conductivity at sites where eucalypts have been recorded. We compare the median predicted geochemistry and reported substrate for individual species that appear associated with extreme conditions; this provides a partial evaluation of the predictions. We generate a site‐by‐species matrix by aggregating observations to the centroids of 100‐km‐wide grid cells, calculate diversity indices, and use numerical ecology methods (ordination, variation partitioning) to investigate the ecology of eucalypts and their response to climatic and geochemical gradients. We find that β‐diversity coincides with variations in climatic and geochemical patterns. Climate and geochemistry together account for less than half of the variation in eucalypt species assemblages across Australia but for greater than 80% in areas of high species richness. Climate is more important than geochemistry in explaining eucalypts species distribution and change in assemblages across Australia as a whole but there are correlations between the two sets of environmental variables. Many individual eucalypt species and entire taxonomic sections (Aromatica, Longistylus of subgenus Eucalyptus, Dumaria, and Liberivalvae of subgenus Symphyomyrtus) have distributions affected strongly by geochemistry. We conclude that eucalypt diversity is driven by steep geochemical gradients that have arisen as climate patterns have fluctuated over Australia over the Cenozoic, generally aridifying since the Miocene. The diversification of eucalypts across Australia is thus an excellent example of co‐evolution of landscapes and biota in space and time and challenges accepted notions of macroecology. 相似文献
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David M. J. S. Bowman Brett P. Murphy Dominic L. J. Neyland Grant J. Williamson Lynda D. Prior 《Global Change Biology》2014,20(3):1008-1015
Obligate seeder trees requiring high‐severity fires to regenerate may be vulnerable to population collapse if fire frequency increases abruptly. We tested this proposition using a long‐lived obligate seeding forest tree, alpine ash (Eucalyptus delegatensis), in the Australian Alps. Since 2002, 85% of the Alps bioregion has been burnt by several very large fires, tracking the regional trend of more frequent extreme fire weather. High‐severity fires removed 25% of aboveground tree biomass, and switched fuel arrays from low loads of herbaceous and litter fuels to high loads of flammable shrubs and juvenile trees, priming regenerating stands for subsequent fires. Single high‐severity fires caused adult mortality and triggered mass regeneration, but a second fire in quick succession killed 97% of the regenerating alpine ash. Our results indicate that without interventions to reduce fire severity, interactions between flammability of regenerating stands and increased extreme fire weather will eliminate much of the remaining mature alpine ash forest. 相似文献
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Elizabeth McLean Suzanne M. Prober William D. Stock René E. Vaillancourt Margaret Byrne 《Molecular ecology》2014,23(10):2500-2513
Patterns of adaptive variation within plant species are best studied through common garden experiments, but these are costly and time‐consuming, especially for trees that have long generation times. We explored whether genome‐wide scanning technology combined with outlier marker detection could be used to detect adaptation to climate and provide an alternative to common garden experiments. As a case study, we sampled nine provenances of the widespread forest tree species, Eucalyptus tricarpa, across an aridity gradient in southeastern Australia. Using a Bayesian analysis, we identified a suite of 94 putatively adaptive (outlying) sequence‐tagged markers across the genome. Population‐level allele frequencies of these outlier markers were strongly correlated with temperature and moisture availability at the site of origin, and with population differences in functional traits measured in two common gardens. Using the output from a canonical analysis of principal coordinates, we devised a metric that provides a holistic measure of genomic adaptation to aridity that could be used to guide assisted migration or genetic augmentation. 相似文献
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Rebecca Jordan Ary A. Hoffmann Shannon K. Dillon Suzanne M. Prober 《Molecular ecology》2017,26(21):6002-6020
Understanding whether populations can adapt in situ or whether interventions are required is of key importance for biodiversity management under climate change. Landscape genomics is becoming an increasingly important and powerful tool for rapid assessments of climate adaptation, especially in long‐lived species such as trees. We investigated climate adaptation in Eucalyptus microcarpa using the DArTseq genomic approach. A combination of FST outlier and environmental association analyses were performed using >4200 genomewide single nucleotide polymorphisms (SNPs) from 26 populations spanning climate gradients in southeastern Australia. Eighty‐one SNPs were identified as putatively adaptive, based on significance in FST outlier tests and significant associations with one or more climate variables related to temperature (70/81), aridity (37/81) or precipitation (35/81). Adaptive SNPs were located on all 11 chromosomes, with no particular region associated with individual climate variables. Climate adaptation appeared to be characterized by subtle shifts in allele frequencies, with no consistent fixed differences identified. Based on these associations, we predict adaptation under projected changes in climate will include a suite of shifts in allele frequencies. Whether this can occur sufficiently rapidly through natural selection within populations, or would benefit from assisted gene migration, requires further evaluation. In some populations, the absence or predicted increases to near fixation of particular adaptive alleles hint at potential limits to adaptive capacity. Together, these results reinforce the importance of standing genetic variation at the geographic level for maintaining species’ evolutionary potential. 相似文献