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Olivier Monteuuis - One of the best experts on this subject based on the ideXlab platform.
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IN VITRO GRAFTING OF WOODY SPECIES
2015Co-Authors: Olivier MonteuuisAbstract:Bon m. C. (1988). J 16: an apex protein associated with juvenility of Sequoiadendron Giganteum. Tree Physiology, 4: 381-387
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DNA methylation in different origin clonal offspring from a mature Sequoiadendron Giganteum genotype
Trees, 2008Co-Authors: Olivier Monteuuis, Sylvie Doulbeau, Jean-luc VerdeilAbstract:A meristem-issued rejuvenated line was obtained in 1986 from a 100-year-old Sequoiadendron Giganteum tree and has been since then micropropagated in tissue culture conditions maintaining its juvenile-like characteristics. By contrast, grafts and rooted microcuttings from the same genotype planted in outdoor conditions for several years exhibited mature foliage traits and the grafts started to produce cones, which are obvious indicators of physiological aging. These three different clonal lines were compared with regard to global DNA methylation assessed by HPLC. The in vitro rejuvenated line showed a much higher level of DNA methylation (23% as average value) than the two other outdoor origins from the same clone which displayed similar degrees of global methylation (average values of 13.4% for the grafts and 13.8% for the cuttings). Overall these DNA global methylation values obtained for the first time in S. Giganteum are consistent with the level of methylation reported for many plants using the same HPLC protocols. The fact that shoots exhibiting a juvenile-like leaf morphology can be characterized by higher DNA methylation than mature-like ones is discussed in relation to physiological aging, referring to other studies on the same topic.
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Rejuvenation of a 100 year old Sequoiadendron Giganteum through in vitro meristem culture ii. biochemical arguments
Physiologia Plantarum, 1991Co-Authors: Marie-claude Bon, Olivier MonteuuisAbstract:The phenomena of phase change and rejuvenation are characterized mainly by morphological and physiological criteria. Thus far, biochemical assessments have been relatively limited. In Sequoiadendron Giganteum, techniques of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and miniaturized two-dimensional gel electrophoresis were applied to a meristem-derived line from a 100-year-old tree to attest the basic origin of the resulting rejuvenation observed from morphological and organogenic standpoints in vitro as well as after acclimation in outdoor conditions. The membrane-associated protein J16, which characterizes the juvenile status was detected in both the juvenile control and the rejuvenated line, while in the original mature form it was totally lacking. In addition, two-dimensional electrophoretic analysis of protein patterns of single meristems belonging to the mature and the rejuvenated form suggested that rejuvenation might involve a drastic modification of the protein content within the meristem itself. (Resume d'auteur)
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Rejuvenation of a 100‐year‐old Sequoiadendron Giganteum through in vitro meristem culture. I. Organogenic and morphological arguments
Physiologia Plantarum, 1991Co-Authors: Olivier MonteuuisAbstract:True-to-type cloning of mature trees, especially when they do not sprout from their base, remains problematic. Special attention is focused on the shoot apical meristem, since it is an obvious choice for vegetative propagation. In Sequoiadendron Giganteum a meristem removed during budbreak from a 100-year-old tree regenerated a truly rejuvenated line that exhibited the same juvenile characters as the juvenile clone used as control, especially in regard to morphological traits and organogenic capacity, and as manifested by the ability to produce adventitious roots in vitro. This rejuvenation has been maintained for 3 years in both in vitro and ex vitro conditions. This result is discussed in terms of inhibitory correlative systems acting within the donor tree in situ, especially as concerns miniaturization of the explant. (Resume d'auteur)
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rejuvenation of a 100 year old Sequoiadendron Giganteum through in vitro meristem culture i organogenic and morphological arguments
Physiologia Plantarum, 1991Co-Authors: Olivier MonteuuisAbstract:True-to-type cloning of mature trees, especially when they do not sprout from their base, remains problematic. Special attention is focused on the shoot apical meristem, since it is an obvious choice for vegetative propagation. In Sequoiadendron Giganteum a meristem removed during budbreak from a 100-year-old tree regenerated a truly rejuvenated line that exhibited the same juvenile characters as the juvenile clone used as control, especially in regard to morphological traits and organogenic capacity, and as manifested by the ability to produce adventitious roots in vitro. This rejuvenation has been maintained for 3 years in both in vitro and ex vitro conditions. This result is discussed in terms of inhibitory correlative systems acting within the donor tree in situ, especially as concerns miniaturization of the explant. (Resume d'auteur)
Rainbow Desilva - One of the best experts on this subject based on the ideXlab platform.
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fragmented and isolated limited gene flow coupled with weak isolation by environment in the paleoendemic giant sequoia Sequoiadendron Giganteum
American Journal of Botany, 2020Co-Authors: Rainbow Desilva, Richard S. DoddAbstract:PREMISE Patterns of genetic structure across a species' range reflect the long-term interplay between genetic drift, gene flow, and selection. Given the importance of gene flow in preventing the loss of diversity through genetic drift among spatially isolated populations, understanding the dynamics of gene flow and the factors that influence connectivity across a species' range is a major goal for conservation of genetic diversity. Here we present a detailed look at gene flow dynamics of Sequoiadendron Giganteum, a paleoendemic tree species that will likely face numerous threats due to climate change. METHODS We used microsatellite markers to examine nineteen populations of S. Giganteum for patterns of genetic structure and to estimate admixture and rates of gene flow between eight population pairs. Also, we used Generalized Dissimilarity Models to elucidate landscape factors that shape genetic differentiation among populations. RESULTS We found minimal gene flow between adjacent groves in the northern disjunct range. In most of the southern portion of the range, groves showed a signal of connectivity which degrades to isolation in the extreme south. Geographic distance was the most important predictor of genetic dissimilarity across the range, with environmental conditions related to precipitation and temperature explaining a small, but significant, portion of the genetic variance. CONCLUSIONS Due to their isolation and unique genetic composition, northern populations of S. Giganteum should be considered a high conservation priority. In this region, we suggest germplasm conservation as well as restoration planting to enhance genetic diversity.
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long term demographic decline and late glacial divergence in a californian paleoendemic Sequoiadendron Giganteum giant sequoia
Ecology and Evolution, 2016Co-Authors: Richard S. Dodd, Rainbow DesilvaAbstract:Mediterranean ecosystems comprise a high proportion of endemic taxa whose response to climate change will depend on their evolutionary origins. In the California flora, relatively little attention has been given to the evolutionary history of paleoendemics from a molecular perspective, yet they number among some of the world's most iconic plant species. Here, we address questions of demographic change in Sequoiadendron Giganteum (giant sequoia) that is restricted to a narrow belt of groves in the Sierra Nevada Mountains. We ask whether the current distribution is a result of northward colonization since the last glacial maximum (LGM), restriction of a broader range in the recent past (LGM) or independent colonizations in the deeper past. Genetic diversity at eleven microsatellite loci decreased with increasing latitude, but partial regressions suggested this was a function of smaller population sizes in the north. Disjunct populations north of the Kings River were divergent from those south of the Kings River that formed a single cluster in Bayesian assignment tests. Demographic inferences supported a demographic contraction just prior to the LGM as the most likely scenario for the current disjunct range of the species. This contraction appeared to be superimposed upon a long-term decline in giant sequoia over the last 2 million years, associated with increasing aridity due to the Mediterranean climate. Overall, low genetic diversity, together with competition in an environment to which giant sequoia is likely already poorly adapted, will pose major constraints on its success in the face of increasing aridity.
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Development and characterization of microsatellite markers for giant sequoia, Sequoiadendron Giganteum (Cupressaceae)
Conservation Genetics Resources, 2013Co-Authors: Rainbow Desilva, Richard S. DoddAbstract:We describe eleven polymorphic microsatellite markers for giant sequoia [Sequoiadendron Giganteum (Lindl.) J. Buchh.], the world’s largest tree. Size-selected genomic DNA was enriched for short sequence repeats (SSR) and the resulting SSR library was analyzed on a Roche 454 platform. DNA samples from seedlings grown in a common garden (n = 359), representing a gene pool from twenty-three groves, were examined for SSR polymorphisms. The total observed alleles per locus ranged from three to twenty-five. Samples from the cabin creek grove (n = 21) exhibit observed heterozygosities ranging from 0.19 to 1.0, with one loci displaying significant deviation from Hardy–Weinberg equilibrium. Within this grove, no loci showed significant linkage disequilibrium. These microsatellite markers are important for assessing and conserving genetic diversity in this rare conifer.
Ramzi Touchan - One of the best experts on this subject based on the ideXlab platform.
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δ 14 c and δ 13 c in annual tree ring samples from Sequoiadendron Giganteum ad 998 1510 solar cycles and climate
Radiocarbon, 2019Co-Authors: Chris Eastoe, Charles S. Tucek, Ramzi TouchanAbstract:Time series of annual Δ 14 C and δ 13 C in tree rings of Sequoiadendron Giganteum , AD 998–1510, are similar in form. The Δ 14 C series completes, with data of Stuiver and Braziunas ( 1993 ), a 957-yr time-series. Discrete Fourier transformation of detrended Δ 14 C reveals periods of 126, 91, 56, 17.6, 13.6, 10.4, and 7.1 yr. Non-random differences exist between decadal averages of the Sequoiadendron Δ 14 C data and data of Stuiver and Becker ( 1993 ). Periods of 7–17 yr may correspond to Schwabe or related climatic cycles; these have 10–17-yr periods and amplitudes 14 C are mainly less than 5‰, and do not constitute convincing evidence of increased 14 C production from supernovae or solar proton events. The δ 13 C time-series is likely to reflect climate change, and for centennial periodicity lags behind Δ 14 C by 20–40 yr (centennial time-scale) and 25–50 yr (millennial). Phase-shifts between solar luminosity and surface Δ 14 C are 125–175 yr and 20 yr for millennial and centennial cycles, respectively. The study suggests that strongest climate effects may therefore follow peak luminosity by 125–175 yr for millennial cycles and 20–40 yr for centennial cycles.
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Δ 14 C and δ 13 C in Annual Tree-Ring Samples from Sequoiadendron Giganteum , AD 998–1510: Solar Cycles and Climate
Radiocarbon, 2019Co-Authors: Chris Eastoe, Charles S. Tucek, Ramzi TouchanAbstract:Time series of annual Δ 14 C and δ 13 C in tree rings of Sequoiadendron Giganteum , AD 998–1510, are similar in form. The Δ 14 C series completes, with data of Stuiver and Braziunas ( 1993 ), a 957-yr time-series. Discrete Fourier transformation of detrended Δ 14 C reveals periods of 126, 91, 56, 17.6, 13.6, 10.4, and 7.1 yr. Non-random differences exist between decadal averages of the Sequoiadendron Δ 14 C data and data of Stuiver and Becker ( 1993 ). Periods of 7–17 yr may correspond to Schwabe or related climatic cycles; these have 10–17-yr periods and amplitudes 14 C are mainly less than 5‰, and do not constitute convincing evidence of increased 14 C production from supernovae or solar proton events. The δ 13 C time-series is likely to reflect climate change, and for centennial periodicity lags behind Δ 14 C by 20–40 yr (centennial time-scale) and 25–50 yr (millennial). Phase-shifts between solar luminosity and surface Δ 14 C are 125–175 yr and 20 yr for millennial and centennial cycles, respectively. The study suggests that strongest climate effects may therefore follow peak luminosity by 125–175 yr for millennial cycles and 20–40 yr for centennial cycles.
Richard S. Dodd - One of the best experts on this subject based on the ideXlab platform.
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fragmented and isolated limited gene flow coupled with weak isolation by environment in the paleoendemic giant sequoia Sequoiadendron Giganteum
American Journal of Botany, 2020Co-Authors: Rainbow Desilva, Richard S. DoddAbstract:PREMISE Patterns of genetic structure across a species' range reflect the long-term interplay between genetic drift, gene flow, and selection. Given the importance of gene flow in preventing the loss of diversity through genetic drift among spatially isolated populations, understanding the dynamics of gene flow and the factors that influence connectivity across a species' range is a major goal for conservation of genetic diversity. Here we present a detailed look at gene flow dynamics of Sequoiadendron Giganteum, a paleoendemic tree species that will likely face numerous threats due to climate change. METHODS We used microsatellite markers to examine nineteen populations of S. Giganteum for patterns of genetic structure and to estimate admixture and rates of gene flow between eight population pairs. Also, we used Generalized Dissimilarity Models to elucidate landscape factors that shape genetic differentiation among populations. RESULTS We found minimal gene flow between adjacent groves in the northern disjunct range. In most of the southern portion of the range, groves showed a signal of connectivity which degrades to isolation in the extreme south. Geographic distance was the most important predictor of genetic dissimilarity across the range, with environmental conditions related to precipitation and temperature explaining a small, but significant, portion of the genetic variance. CONCLUSIONS Due to their isolation and unique genetic composition, northern populations of S. Giganteum should be considered a high conservation priority. In this region, we suggest germplasm conservation as well as restoration planting to enhance genetic diversity.
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long term demographic decline and late glacial divergence in a californian paleoendemic Sequoiadendron Giganteum giant sequoia
Ecology and Evolution, 2016Co-Authors: Richard S. Dodd, Rainbow DesilvaAbstract:Mediterranean ecosystems comprise a high proportion of endemic taxa whose response to climate change will depend on their evolutionary origins. In the California flora, relatively little attention has been given to the evolutionary history of paleoendemics from a molecular perspective, yet they number among some of the world's most iconic plant species. Here, we address questions of demographic change in Sequoiadendron Giganteum (giant sequoia) that is restricted to a narrow belt of groves in the Sierra Nevada Mountains. We ask whether the current distribution is a result of northward colonization since the last glacial maximum (LGM), restriction of a broader range in the recent past (LGM) or independent colonizations in the deeper past. Genetic diversity at eleven microsatellite loci decreased with increasing latitude, but partial regressions suggested this was a function of smaller population sizes in the north. Disjunct populations north of the Kings River were divergent from those south of the Kings River that formed a single cluster in Bayesian assignment tests. Demographic inferences supported a demographic contraction just prior to the LGM as the most likely scenario for the current disjunct range of the species. This contraction appeared to be superimposed upon a long-term decline in giant sequoia over the last 2 million years, associated with increasing aridity due to the Mediterranean climate. Overall, low genetic diversity, together with competition in an environment to which giant sequoia is likely already poorly adapted, will pose major constraints on its success in the face of increasing aridity.
-
Development and characterization of microsatellite markers for giant sequoia, Sequoiadendron Giganteum (Cupressaceae)
Conservation Genetics Resources, 2013Co-Authors: Rainbow Desilva, Richard S. DoddAbstract:We describe eleven polymorphic microsatellite markers for giant sequoia [Sequoiadendron Giganteum (Lindl.) J. Buchh.], the world’s largest tree. Size-selected genomic DNA was enriched for short sequence repeats (SSR) and the resulting SSR library was analyzed on a Roche 454 platform. DNA samples from seedlings grown in a common garden (n = 359), representing a gene pool from twenty-three groves, were examined for SSR polymorphisms. The total observed alleles per locus ranged from three to twenty-five. Samples from the cabin creek grove (n = 21) exhibit observed heterozygosities ranging from 0.19 to 1.0, with one loci displaying significant deviation from Hardy–Weinberg equilibrium. Within this grove, no loci showed significant linkage disequilibrium. These microsatellite markers are important for assessing and conserving genetic diversity in this rare conifer.
Th. Gaspar - One of the best experts on this subject based on the ideXlab platform.
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Uptake, distribution and metabolism of 2,4-dichlorophenoxyacetic acid in shoots of juvenile and mature clones of Sequoiadendron Giganteum in relation to rooting in vitro [rhizogenesis]
Plant Physiology and Biochemistry, 1991Co-Authors: J.y. Berthon, N. Boyer, Th. GasparAbstract:L'acide 2,4-dichlorophenoxyacetique a ete apporte a des explants de Sequoiadendron Giganteum issus de multiplication a partir d'explants preleves sur des boutures juveniles (semis de 12 mois) et matures (arbre de 30 ans) durant la phase d'induction racinaire in vitro
