The Experts below are selected from a list of 34203 Experts worldwide ranked by ideXlab platform
Douglass F Jacobs - One of the best experts on this subject based on the ideXlab platform.
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Walnut (Juglans spp.) Ecophysiology in response to environmental stresses and potential acclimation to climate change
Annals of Forest Science, 2011Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:• Context Walnuts ( Juglans spp.) are ecologically and commercially important trees, yet synthesis of past and current research findings on walnut Ecophysiology is lacking, especially in terms of potential acclimation to climate change. • Aims This study aims to (1) investigate walnut Ecophysiology by comparing its attributes to associated deciduous angiosperms, (2) address potential acclimation of walnut to climate change, and (3) identify areas for prioritization in future research. • Results There is considerable uncertainty regarding the magnitude of potential effects of climate change on walnut. Some studies tend to indicate walnut could be negatively impacted by climate change, while others do not. Walnut may be at a disadvantage due to its susceptibility to drought and frost injury in current growing regions given the projected increases in temperature and extreme climatic events. Other regions that are currently considered cold for walnut growth may see increased establishment and growth depending upon the rate of temperature increase and the frequency and severity of extreme climatic events. • Conclusion Research investigating a combination of environmental factors, such as temperature, carbon dioxide, ozone, water, and nitrogen is needed to (1) better project climate change effects on walnut and (2) develop management strategies for walnut acclimation and adaptation to climate change.
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walnut juglans spp Ecophysiology in response to environmental stresses and potential acclimation to climate change
Annals of Forest Science, 2011Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:• Context Walnuts (Juglans spp.) are ecologically and commercially important trees, yet synthesis of past and current research findings on walnut Ecophysiology is lacking, especially in terms of potential acclimation to climate change.
Martinmichel Gauthier - One of the best experts on this subject based on the ideXlab platform.
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Walnut (Juglans spp.) Ecophysiology in response to environmental stresses and potential acclimation to climate change
Annals of Forest Science, 2011Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:• Context Walnuts ( Juglans spp.) are ecologically and commercially important trees, yet synthesis of past and current research findings on walnut Ecophysiology is lacking, especially in terms of potential acclimation to climate change. • Aims This study aims to (1) investigate walnut Ecophysiology by comparing its attributes to associated deciduous angiosperms, (2) address potential acclimation of walnut to climate change, and (3) identify areas for prioritization in future research. • Results There is considerable uncertainty regarding the magnitude of potential effects of climate change on walnut. Some studies tend to indicate walnut could be negatively impacted by climate change, while others do not. Walnut may be at a disadvantage due to its susceptibility to drought and frost injury in current growing regions given the projected increases in temperature and extreme climatic events. Other regions that are currently considered cold for walnut growth may see increased establishment and growth depending upon the rate of temperature increase and the frequency and severity of extreme climatic events. • Conclusion Research investigating a combination of environmental factors, such as temperature, carbon dioxide, ozone, water, and nitrogen is needed to (1) better project climate change effects on walnut and (2) develop management strategies for walnut acclimation and adaptation to climate change.
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walnut juglans spp Ecophysiology in response to environmental stresses and potential acclimation to climate change
Annals of Forest Science, 2011Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:• Context Walnuts (Juglans spp.) are ecologically and commercially important trees, yet synthesis of past and current research findings on walnut Ecophysiology is lacking, especially in terms of potential acclimation to climate change.
Jaroslav Klápště - One of the best experts on this subject based on the ideXlab platform.
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genome wide association implicates numerous genes underlying ecological trait variation in natural populations of populus trichocarpa
New Phytologist, 2014Co-Authors: Athena D. Mckown, Jaroslav Klápště, Robert D. Guy, Armando Geraldes, Michael Friedmann, Ilga Porth, Jan Hannemann, Wellington Muchero, Gerald A TuskanAbstract:Summary In order to uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa) from much of its range in western North America. Extensive data from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34 K Populus single nucleotide polymorphism (SNP) array) of all accessions were used for gene discovery in a genome-wide association study (GWAS). We performed GWAS with 40 biomass, Ecophysiology and phenology traits and 29 355 filtered SNPs representing 3518 genes. The association analyses were carried out using a Unified Mixed Model accounting for population structure effects among accessions. We uncovered 410 significant SNPs using a Bonferroni-corrected threshold (P < 1.7 × 10−6). Markers were found across 19 chromosomes, explained 1–13% of trait variation, and implicated 275 unique genes in trait associations. Phenology had the largest number of associated genes (240 genes), followed by biomass (53 genes) and Ecophysiology traits (25 genes). The GWAS results propose numerous loci for further investigation. Many traits had significant associations with multiple genes, underscoring their genetic complexity. Genes were also identified with multiple trait associations within and/or across trait categories. In some cases, traits were genetically correlated while in others they were not.
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geographical and environmental gradients shape phenotypic trait variation and genetic structure in populus trichocarpa
New Phytologist, 2014Co-Authors: Athena D. Mckown, Jaroslav Klápště, Robert D. Guy, Shawn D. Mansfield, Armando Geraldes, Michael Friedmann, Quentin C B Cronk, Yousry A Elkassaby, Carl J. DouglasAbstract:• Populus trichocarpa is widespread across western North America spanning extensive variation in photoperiod, growing season and climate. We investigated trait variation in P. trichocarpa using over 2000 trees from a common garden at Vancouver, Canada, representing replicate plantings of 461 genotypes originating from 136 provenance localities. • We measured 40 traits encompassing phenological events, biomass accumulation, growth rates, and leaf, isotope and gas exchange-based Ecophysiology traits. With replicated plantings and 29,354 single nucleotide polymorphisms (SNPs) from 3518 genes, we estimated both broad-sense trait heritability (H(2)) and overall population genetic structure from principal component analysis. • Populus trichocarpa had high phenotypic variation and moderate/high H(2) for many traits. H(2) ranged from 0.3 to 0.9 in phenology, 0.3 to 0.8 in biomass and 0.1 to 0.8 in Ecophysiology traits. Most traits correlated strongly with latitude, maximum daylength and temperature of tree origin, but not necessarily with elevation, precipitation or heat : moisture indices. Trait H(2) values reflected trait correlation strength with geoclimate variables. The population genetic structure had one significant principal component (PC1) which correlated with daylength and showed enrichment for genes relating to circadian rhythm and photoperiod. • Robust relationships between traits, population structure and geoclimate in P. trichocarpa reflect patterns which suggest that range-wide geographical and environment gradients have shaped its genotypic and phenotypic variability.
Marcel Prévost - One of the best experts on this subject based on the ideXlab platform.
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physiology and growth of advance picea rubens and abies balsamea regeneration following different canopy openings
Tree Physiology, 2014Co-Authors: Daniel Dumais, Marcel PrévostAbstract:We examined the Ecophysiology and growth of 0.3-1.3 m tall advance red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea [L.] Mill.) regeneration during a 5-year period following the application of different harvest types producing three sizes of canopy openings: (i) small gaps (<100 m(2) in area; SMA) created by partial uniform single-tree harvest; (ii) irregular gaps of intermediate size (100-300 m(2); INT) created by group-selection harvest (removal of groups of trees, mainly balsam fir, with uniform partial removal between groups); and (iii) large circular gaps (700 m(2); LAR) created by patch-selection harvest (removal of trees in 30-m diameter circular areas with uniform partial removal between gaps). An unharvested control (CON) was monitored for comparison. At the ecophysiological level, we mainly found differences in light-saturated photosynthesis of red spruce and specific leaf area of balsam fir among treatments. Consequently, we observed good height growth of both species in CON and INT, but fir surpassed spruce in SMA and LAR. Results suggest that intermediate 100-300 m(2) irregular openings create microenvironmental conditions that may promote short-term Ecophysiology and growth of red spruce, allowing the species to compete with balsam fir advance regeneration. Finally, results observed for spruce in large 700-m(2) openings confirm its inability to grow as rapidly as fir in comparable open conditions.
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Physiology and growth of advance Picea rubens and Abies balsamea regeneration following different canopy openings.
Tree physiology, 2014Co-Authors: Daniel Dumais, Marcel PrévostAbstract:We examined the Ecophysiology and growth of 0.3-1.3 m tall advance red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea [L.] Mill.) regeneration during a 5-year period following the application of different harvest types producing three sizes of canopy openings: (i) small gaps (
Athena D. Mckown - One of the best experts on this subject based on the ideXlab platform.
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genome wide association implicates numerous genes underlying ecological trait variation in natural populations of populus trichocarpa
New Phytologist, 2014Co-Authors: Athena D. Mckown, Jaroslav Klápště, Robert D. Guy, Armando Geraldes, Michael Friedmann, Ilga Porth, Jan Hannemann, Wellington Muchero, Gerald A TuskanAbstract:Summary In order to uncover the genetic basis of phenotypic trait variation, we used 448 unrelated wild accessions of black cottonwood (Populus trichocarpa) from much of its range in western North America. Extensive data from large-scale trait phenotyping (with spatial and temporal replications within a common garden) and genotyping (with a 34 K Populus single nucleotide polymorphism (SNP) array) of all accessions were used for gene discovery in a genome-wide association study (GWAS). We performed GWAS with 40 biomass, Ecophysiology and phenology traits and 29 355 filtered SNPs representing 3518 genes. The association analyses were carried out using a Unified Mixed Model accounting for population structure effects among accessions. We uncovered 410 significant SNPs using a Bonferroni-corrected threshold (P < 1.7 × 10−6). Markers were found across 19 chromosomes, explained 1–13% of trait variation, and implicated 275 unique genes in trait associations. Phenology had the largest number of associated genes (240 genes), followed by biomass (53 genes) and Ecophysiology traits (25 genes). The GWAS results propose numerous loci for further investigation. Many traits had significant associations with multiple genes, underscoring their genetic complexity. Genes were also identified with multiple trait associations within and/or across trait categories. In some cases, traits were genetically correlated while in others they were not.
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geographical and environmental gradients shape phenotypic trait variation and genetic structure in populus trichocarpa
New Phytologist, 2014Co-Authors: Athena D. Mckown, Jaroslav Klápště, Robert D. Guy, Shawn D. Mansfield, Armando Geraldes, Michael Friedmann, Quentin C B Cronk, Yousry A Elkassaby, Carl J. DouglasAbstract:• Populus trichocarpa is widespread across western North America spanning extensive variation in photoperiod, growing season and climate. We investigated trait variation in P. trichocarpa using over 2000 trees from a common garden at Vancouver, Canada, representing replicate plantings of 461 genotypes originating from 136 provenance localities. • We measured 40 traits encompassing phenological events, biomass accumulation, growth rates, and leaf, isotope and gas exchange-based Ecophysiology traits. With replicated plantings and 29,354 single nucleotide polymorphisms (SNPs) from 3518 genes, we estimated both broad-sense trait heritability (H(2)) and overall population genetic structure from principal component analysis. • Populus trichocarpa had high phenotypic variation and moderate/high H(2) for many traits. H(2) ranged from 0.3 to 0.9 in phenology, 0.3 to 0.8 in biomass and 0.1 to 0.8 in Ecophysiology traits. Most traits correlated strongly with latitude, maximum daylength and temperature of tree origin, but not necessarily with elevation, precipitation or heat : moisture indices. Trait H(2) values reflected trait correlation strength with geoclimate variables. The population genetic structure had one significant principal component (PC1) which correlated with daylength and showed enrichment for genes relating to circadian rhythm and photoperiod. • Robust relationships between traits, population structure and geoclimate in P. trichocarpa reflect patterns which suggest that range-wide geographical and environment gradients have shaped its genotypic and phenotypic variability.
