Larix laricina

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Fitzpatrick-cooper Julia - One of the best experts on this subject based on the ideXlab platform.

Pierre J. Charest - One of the best experts on this subject based on the ideXlab platform.

  • Transgenic Black Spruce (Picea mariana)
    Transgenic Trees, 2000
    Co-Authors: Lining Tian, Armand Séguin, Robert G. Rutledge, Pierre J. Charest
    Abstract:

    Black spruce (Picea mariana) is one of about 40 species of the genus Picea A. Dietr. (family Pinaceae) scattered throughout the cooler parts of the north temperate zone and higher elevations in the south (Farrar 1995). Alone or with white spruce and tamarack [Larix laricina (Du Roi) K. Koch], black spruce forms the northern boundary of tree-form growth.

  • Larix laricina (tamarack): somatic embryogenesis and genetic transformation.
    Canadian Journal of Forest Research, 1997
    Co-Authors: Krystyna Klimaszewska, Y. Devantier, D. Lachance, Marie-anne Lelu, Pierre J. Charest
    Abstract:

    Excised, immature zygotic embryos of Larix laricina (Du Roi) K. Koch (tamarack) gave rise to embryogenic cultures on modified Murashige and Skoog (MSG) medium supplemented with growth regulators. Three lines of embryonal masses were maintained for 1 year by biweekly subcultures prior to the maturation experiments. All of these lines showed the ability to produce mature somatic embryos. Both elevated medium osmolality (315.0n543.6 mmol·kg n1 ) and presence of abscisic acid (ABA) at 40 μM stimulated the maturation process when applied simultaneously. Sucrose was most effective at 0.4 M, and polyethylene glycol (PEG) at 5 or 10% was effective only in combination with 0.2 or 0.4 M sucrose. The germination frequency of somatic embryos depended on both osmolality and ABA concentration in the maturation medium. Over 90% of mature somatic embryos were capable of secondary somatic embryogenesis when placed on the induction medium. This particular ability was exploited in order to achieve genetic transformation. Four vectors were delivered to the embryonal masses and somatic embryo cells via bombardment of DNA-coated gold particles. The vectors pBI426 and pRT99gus carried a gene encoding resistance to kanamycin, pRT66gus to hygromycin, and pRT55gus to methotrexate. All vectors carried the gene coding for β-glucuronidase (GUS) and were over 6 kilobases in size. Assays for both transient and stable transformation were carried out. The only vector that yielded two transgenic lines was pBI426. These lines of embryonal masses, designated as 2D1 and 2D2, were analysed by hybridization of the plasmid to the genomic Southern blots and revealed several insertions of the vector. Line 2D1 gave rise to young germinants that expressed the GUS gene uniformly throughout the root, hypocotyl, and cotyledons but failed to develop further. Line 2D2 gave rise to transgenic plants that displayed random and ipatchyi expression of the GUS gene. Polymerase chain reaction (PCR) amplification of the GUS insert in 6-month-old 2D2 transgenic plants showed the presence of diagnostic fragment in all parts of the plants. Resume : Des embryons zygotiques immatures de Larix laricina (Du Roi) K. Koch (mOlze laricin) ont donnO du tissu embryogne sur un milieu Murashige et Skoog modifiO (MSG) par liajout de rOgulateurs de croissance. Trois lignOes embryognes ont OtO maintenues pendant 1 an par sous-cultures bihebdomadaires avant les expOriences de maturation. Ces trois lignOes ont dOmontrO leur aptitude ‡ produire des embryons somatiques matures. Une osmolalitO OlevOe (315,0n

  • Larix laricina (tamarack): somatic embryogenesis and genetic transformation
    Canadian Journal of Forest Research, 1997
    Co-Authors: Krystyna Klimaszewska, Y. Devantier, D. Lachance, Marie-anne Lelu-walter, Pierre J. Charest
    Abstract:

    Excised, immature zygotic embryos of Larix laricina (Du Roi) K. Koch (tamarack) gave rise to embryogenic cultures on modified Murashige and Skoog (MSG) medium supplemented with growth regulators. Three lines of embryonal masses were maintained for 1 year by biweekly subcultures prior to the maturation experiments. All of those lines showed the ability to produce mature somatic embryos. Both elevated medium osmolality (315.0-543.6 mmol.kg(-1)) and presence of abscisic acid (ABA) at 40 mu M stimulated the maturation process when applied simultaneously. Sucrose was most effective at 0.4 M, and polyethylene glycol (PEG) at 5 or 10% was effective only in combination with 0.2 or 0.4 M sucrose. The germination frequency of somatic embryos depended on both osmolality and ABA concentration in the maturation medium. Over 90%;, of mature somatic embryos were capable of secondary somatic embryogenesis when placed on the induction medium. This particular ability was exploited in order to achieve genetic transformation. Four vectors were delivered to the embryonal masses and somatic embryo cells via bombardment of DNA-coated Sold particles. The vectors pBI426 and pRT99gus carried a gene encoding resistance to kanamycin, pRT66gus to hygromycin, and pRT55gus to methotrexate. All vectors carried the gene coding for beta-glucuronidase (GUS) and were over 6 kilobases in size. Assays for both transient and stable transformation were carried out. The only vector that yielded two transgenic lines was pBI426. These lines of embryonal masses, designated as 2D1 and 2D2, were analysed by hybridization of the plasmid to the genomic Southern blots and revealed several insertions of the vector. Line 2D1 gave rise to young germinants that expressed the GUS gene uniformly throughout the root, hypocotyl, and cotyledons but failed to develop further. Line 2D2 gave rise to transgenic plants that displayed random and ''patchy'' expression of the GUS gene. Polymerase chain reaction (PCR) amplification of the GUS insert in 6-month-old 2D2 transgenic plants showed the presence of diagnostic fragment in all parts of the plants.

Yves Bergeron - One of the best experts on this subject based on the ideXlab platform.

  • Radial growth analysis of Larix laricina from the Lake Duparquet area, Québec, in relation to climate and larch sawfly outbreaks
    Ecoscience, 2016
    Co-Authors: Martin-philippe Girardin, Jacques Tardif, Yves Bergeron
    Abstract:

    AbstractA dendrochronological study was performed at six sites dominated by eastern larch, Larix laricina in Quebec’s southwestern boreal forest. The objectives were to reconstruct periods of larch sawfly (Pristiphora erichsonii) outbreak in the region and to determine which physical factors (precipitation, temperature, water level or drought) explained the greatest variation in radial growth. From the presence of light latewood rings followed by periods of growth suppression, we identified larch sawfly outbreaks for the years 1895-1912, 1937-1942, and 1955-1962. We suspect that additional outbreaks occurred in the early 1920s, late 1970s and early 1980s as well, but at the same time as spruce budworm outbreaks (Choristoneura fumiferana). Response function analysis demonstrated negative relationships between larch radial growth and May and August precipitation and May and September current year water level, and demonstrated positive relationships with May current year drought index and September previous ...

  • Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest
    Botany, 2001
    Co-Authors: Martin-philippe Girardin, Jacques C. Tardif, Yves Bergeron
    Abstract:

    With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the dis - tribution of these clusters was mainly related to ( i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.

  • Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest
    Canadian Journal of Botany, 2001
    Co-Authors: Martin-philippe Girardin, Jacques C. Tardif, Yves Bergeron
    Abstract:

    With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the distribution of these clusters was mainly related to (i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.Key words: larch, wetland, vegetation analysis, flooding, boreal forest.

Janusz J. Zwiazek - One of the best experts on this subject based on the ideXlab platform.

  • Role of adventitious roots in water relations of tamarack ( Larix laricina ) seedlings exposed to flooding
    BMC Plant Biology, 2012
    Co-Authors: Mónica Calvo-polanco, Jorge Señorans, Janusz J. Zwiazek
    Abstract:

    Background Flooding reduces supply of oxygen to the roots affecting plant water uptake. Some flooding-tolerant tree species including tamarack (Larix laricina (Du Roi) K. Koch) produce adventitious roots in response to flooding. These roots were reported to have higher hydraulic conductivity under flooding conditions compared with non-adventitious roots. In the present study, we examined structural and functional modifications in adventitious roots of tamarack seedlings to explain their flooding tolerance.

  • Responses of black spruce (Picea mariana) and tamarack (Larix laricina) to flooding and ethylene
    Tree Physiology, 2003
    Co-Authors: M. Anisul Islam, S. Ellen Macdonald, Janusz J. Zwiazek
    Abstract:

    Black spruce (Picea mariana (Mill.) BSP) and tamarack (Larix laricina (Du Roi) K. Koch) are the predominant tree species in the boreal peatlands of Alberta, Canada, where low nutrient availability, low soil temperature and a high water table limit their growth. Effects of flooding for 28 days on morphological and physiological responses were investigated in greenhouse-grown black spruce and tamarack seedlings in a growth chamber. Flooding reduced root hydraulic conductance, net assimilation rate and stomatal conductance, and increased water-use efficiency (WUE) and needle electrolyte leakage in both species. Although flooded black spruce seedlings maintained higher net assimilation rates and stomatal conductance than flooded tamarack seedlings, flooded tamarack seedlings were able to maintain higher root hydraulic conductance than flooded black spruce seedlings. Needles of flooded black spruce developed tip necrosis and electrolyte leakage after 14 days of flooding, and these symptoms were subsequently more prominent than in needles of flooded tamarack seedlings. Flooded tamarack seedlings exhibited no visible injury symptoms and developed hypertrophied lenticels at their stem base. Application of exogenous ethylene resulted in a significant reduction in net assimilation, stomatal conductance and root respiration, whereas root hydraulic conductivity increased in both species. Thus, although flooded black spruce seedlings maintained a higher stomatal conductance and net assimilation rate than tamarack seedlings, black spruce did not cope with the deleterious effects of prolonged soil flooding and exogenous ethylene as well as tamarack.

  • Responses of black spruce (Picea mariana) and tamarack (Larix laricina) to flooding and ethylene
    Tree Physiology, 2003
    Co-Authors: M. Anisul Islam, S. Ellen Macdonald, Janusz J. Zwiazek
    Abstract:

    Black spruce (Picea mariana (Mill.) BSP) and tamarack (Larix laricina (Du Roi) K. Koch) are the predominant tree species in the boreal peatlands of Alberta, Canada, where low nutrient availability, low soil temperature and a high water table limit their growth. Effects of flooding for 28 days on morphological and physiological responses were investigated in greenhouse-grown black spruce and tamarack seedlings in a growth chamber. Flooding reduced root hydraulic conductance, net assimilation rate and stomatal conductance, and increased water-use efficiency (WUE) and needle electrolyte leakage in both species. Although flooded black spruce seedlings maintained higher net assimilation rates and stomatal conductance than flooded tamarack seedlings, flooded tamarack seedlings were able to maintain higher root hydraulic conductance than flooded black spruce seedlings. Needles of flooded black spruce developed tip necrosis and electrolyte leakage after 14 days of flooding, and these symptoms were subsequently more prominent than in needles of flooded tamarack seedlings. Flooded tamarack seedlings exhibited no visible injury symptoms and developed hypertrophied lenticels at their stem base. Application of exogenous ethylene resulted in a significant reduction in net assimilation, stomatal conductance and root respiration, whereas root hydraulic conductivity increased in both species. Thus, although flooded black spruce seedlings maintained a higher stomatal conductance and net assimilation rate than tamarack seedlings, black spruce did not cope with the deleterious effects of prolonged soil flooding and exogenous ethylene as well as tamarack.

Martin-philippe Girardin - One of the best experts on this subject based on the ideXlab platform.

  • Radial growth analysis of Larix laricina from the Lake Duparquet area, Québec, in relation to climate and larch sawfly outbreaks
    Ecoscience, 2016
    Co-Authors: Martin-philippe Girardin, Jacques Tardif, Yves Bergeron
    Abstract:

    AbstractA dendrochronological study was performed at six sites dominated by eastern larch, Larix laricina in Quebec’s southwestern boreal forest. The objectives were to reconstruct periods of larch sawfly (Pristiphora erichsonii) outbreak in the region and to determine which physical factors (precipitation, temperature, water level or drought) explained the greatest variation in radial growth. From the presence of light latewood rings followed by periods of growth suppression, we identified larch sawfly outbreaks for the years 1895-1912, 1937-1942, and 1955-1962. We suspect that additional outbreaks occurred in the early 1920s, late 1970s and early 1980s as well, but at the same time as spruce budworm outbreaks (Choristoneura fumiferana). Response function analysis demonstrated negative relationships between larch radial growth and May and August precipitation and May and September current year water level, and demonstrated positive relationships with May current year drought index and September previous ...

  • Radial Growth of Tamarack (Larix laricina) in the Churchill Area, Manitoba, Canada, in Relation to Climate and Larch Sawfly (Pristiphora erichsonii) Herbivory
    Arctic Antarctic and Alpine Research, 2005
    Co-Authors: Martin-philippe Girardin, Jacques C. Tardif, Eric Berglund, Kim Monson
    Abstract:

    Abstract Tree-ring chronologies for tamarack (Larix laricina (Du Roi) K. Koch) growing in four stand types covering a dry-to-wet gradient were developed to investigate the association between radial growth and climate as well as evidence of larch sawfly (Pristiphora erichsonii Hartig) herbivory near Churchill, subarctic Manitoba. The chronologies, produced using both living and subfossil material, were well replicated for the period 1800 to 2000. Our results indicated that climate explained more than 60% of the growth variation in tamarack with temperature from May to July of the growing season being most important. This was unusual considering that other studies showed a weak radial growth-climate association in tamarack because of signal contamination due to severe larch sawfly defoliation. Potential outbreak episodes were investigated by looking at pointer years and by contrasting the variance within the tamarack tree-ring series with that observed in climate and in nonhost species. A weak corresponden...

  • Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest
    Botany, 2001
    Co-Authors: Martin-philippe Girardin, Jacques C. Tardif, Yves Bergeron
    Abstract:

    With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the dis - tribution of these clusters was mainly related to ( i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.

  • Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest
    Canadian Journal of Botany, 2001
    Co-Authors: Martin-philippe Girardin, Jacques C. Tardif, Yves Bergeron
    Abstract:

    With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the distribution of these clusters was mainly related to (i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.Key words: larch, wetland, vegetation analysis, flooding, boreal forest.

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