Two highly divergent 5S rDNA unit size classes occur in composite tandem array in European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi (Lamb.) Carr.)

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 837-848 ◽  
Author(s):  
Jean-François Trontin ◽  
Catherine Grandemange ◽  
Jean-Michel Favre
Keyword(s):  
5S Rdna ◽  
Larix Decidua ◽  
Tandem Array ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Unit Size ◽  
European Larch ◽  
Rdna Unit ◽  
Size Classes

Two highly divergent 5S rDNA unit size classes occur in composite tandem array in European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi (Lamb.) Carr.)

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 837-848 ◽  
Author(s):  
Jean-François Trontin ◽  
Catherine Grandemange ◽  
Jean-Michel Favre
Keyword(s):  
Sequence Analysis ◽  
Pinus Radiata ◽  
Sequence Comparison ◽  
5S Rdna ◽  
Larix Decidua ◽  
Tandem Array ◽  
Rrna Genes ◽  
Larix Kaempferi ◽  
Unit Size ◽  
Size Classes

The 5S ribosomal DNA unit structure and organization have been investigated in Larix decidua and Larix kaempferi using selective amplification of gene and spacer, sequence analysis and homologous probe hybridization. Two highly divergent unit size classes of approximately 650 and 870 bp were detected in both species. Sequence analysis in Larix decidua revealed that length variations occur in the middle spacer region and are the result of duplications (in the long spacers) and considerable sequence heterogeneity. Conversely, the transcribed region is of uniform length (120 bp), and the nucleotide sequence of one Larix decidua clone is similar to that reported for other gymnosperms. Sequence comparison of the larch spacers with two other Pinaceae species (Pinus radiata and Picea glauca) showed that the 5' and 3' regions flanking the gene (40 and 60 bp, respectively) are quite conserved, suggesting a regulatory role. Moreover, a small element of about 70 bp located in the middle spacer region was found to be common to the larch long units and the six Pinus radiata spacer clones previously sequenced (64% sequence identity). The short and long unit size classes are mainly organized in composite tandem array(s) with evidence of extensive zones of strict alternation in both species. Mechanisms underlying this unusual association of divergent units in larch 5S rDNA arrays are discussed.Key words: 5S rRNA genes, spacer variations, cluster organization, sequence comparison, Gymnosperms.

A novel approach for the operational production of hybrid larch seeds under northern climatic conditions

2008 ◽  
Vol 84 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Fabienne Colas ◽  
Martin Perron ◽  
Denise Tousignant ◽  
Carol Parent ◽  
Monique Pelletier ◽  
...  
Keyword(s):  
Wood Quality ◽  
Time Lag ◽  
Seed Orchard ◽  
Larix Decidua ◽  
Climatic Conditions ◽  
Snow Accumulation ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Hybrid Larch ◽  
European Larch

Hybrid larch ([Larix × marschlinsii Coaz], HL) is sought after by the forest industry because of its growth characteristics, excellent wood quality and disease resistance. However, the difficulty in obtaining HL seeds limits the production of seedlings for reforestation. Both European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi [Lamb.] Carrière) produce few seeds and the time lag in their flowering phenology complicates their natural pollination. We have developed a novel type of sheltered seed orchard, dedicated to the production of HL seeds from grafts grown in pots. Inverting the arches of a conventional tunnel provides a sturdy structure which is easy to maintain. Because of its height, the tunnel can accommodate the rapid growth of the trees, which reduces the need for pruning. The tunnels are covered in the winter and spring. In the winter, the covers prevent snow accumulation. In the spring, they create a "greenhouse effect" inside the tunnels, accelerating flower development, preventing pollen contamination from trees outside the tunnels and protecting the flowers from late spring frosts. Over the past five years, flowering has been regular and abundant. Bagging the crowns for pollen harvest is cost-effective and yields large quantities of high quality pollen. Pollination operations are conducted using an electrostatic pistol. Because of the large number of available clones, large quantities of seeds with a high genetic variability can be produced at a competitive cost. In 2006, this seed orchard concept was implemented operationally at the Berthier forest nursery (Québec, Canada). Key words: Japanese larch (Larix kaempferi [Lamb.] Carrière), European larch (Larix decidua Mill.), seed production, electrostatic pollination, indoor seed orchard

scholarly journals Study results of pine and larch provenance trial in Serebryanoborsky experimental forest district

2020 ◽  
Vol 24 (6) ◽  
pp. 34-43
Author(s):  
M.D. Merzlenko ◽  
◽  
P.G. Melnik ◽  
Yu.B. Glazunov ◽  
A.A. Kozhenkova ◽  
...  
Keyword(s):  
Siberian Larch ◽  
Japanese Larch ◽  
Stem Volume ◽  
Larix Kaempferi ◽  
Provenance Trial ◽  
European Larch ◽  
Southern Sakhalin ◽  
Study Results ◽  
Larch Species ◽  
Forest District

The results of the cultivation of Scots pine (Pinus sylvestris L.) in the provenance trial in the Serebryanoborsky experimental forest district of the Institute of Forestry of the Russian Academy of Sciences are summarized. The silvicultural effect was assessed by a comprehensive indicator of the feasibility of introducing specific pine conventions. It was established that the use of pine seeds of exclusively local provenances cannot be considered justified. In the vast area of pine there are very remote populations of a local nature, the seed of which, when moved, can be successfully used to create highly productive artificial stands. The 68 year old geographical plantations of larch growth and production rates of 18 climotypes of 14 larch species were compared. These species are Polish larch (Larix polonica Racib.), European larch (Larix decidua Mill. f. Sudetica), Larix sukaczewii Dylis, Siberian larch (Larix sibirika Ledeb.), Larix cajanderi Mayr., Larix gmelinii Rupr., Larix Czekanovskii Szaf, Larix amurensis Kolesn., Olgan larch (Larix olgensis Henry), Japanese larch (Larix kaempferi (Lamb.) Carrière), Larix kurilensis Maur., Larix principis Rupprechtii Maur., Larix potaninii Bat, American larch (Larix laricina (Duroi) K. Koch). Polish larch, Japanese larch, European larch and Olgan larch have the best growth rate results. Climotypes from Siberia and American larch showed worst results. Polish larch (812 m3/ha) and Japanese (804 m3/ha) larch from the Southern Sakhalin have the highest stem volume. The final estimations showed that the climotypes of Polish larch, European larch from Sudetes and Japanese larch from the Southern Sakhalin are suitable for introduction in the Moscow Region. The climotypes from the Far East, namely Larix amurensis Kolesn., Olgan larch and Larix kurilensis Maur., had positive silvicultural effect. The inland climotypes from Asia together with American larch showed negative results.

scholarly journals Complete Chloroplast Genome of Japanese Larch (Larix kaempferi): Insights into Intraspecific Variation with an Isolated Northern Limit Population

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 884
Author(s):  
Shufen Chen ◽  
Wataru Ishizuka ◽  
Toshihiko Hara ◽  
Susumu Goto
Keyword(s):  
Chloroplast Genome ◽  
Intraspecific Variation ◽  
Japanese Larch ◽  
Monophyletic Group ◽  
Phylogenetic Position ◽  
Larix Kaempferi ◽  
Northern Limit ◽  
Complete Chloroplast Genome ◽  
Intraspecific Variations ◽  
Cpdna Markers

Research Highlights: The complete chloroplast genome for eight individuals of Japanese larch, including from the isolated population at the northern limit of the range (Manokami larch), revealed that Japanese larch forms a monophyletic group, within which Manokami larch can be phylogenetically placed in Japanese larch. We detected intraspecific variation for possible candidate cpDNA markers in Japanese larch. Background and Objectives: The natural distribution of Japanese larch is limited to the mountainous range in the central part of Honshu Island, Japan, with an isolated northern limit population (Manokami larch). In this study, we determined the phylogenetic position of Manokami larch within Japanese larch, characterized the chloroplast genome of Japanese larch, detected intraspecific variation, and determined candidate cpDNA markers. Materials and Methods: The complete genome sequence was determined for eight individuals, including Manokami larch, in this study. The genetic position of the northern limit population was evaluated using phylogenetic analysis. The chloroplast genome of Japanese larch was characterized by comparison with eight individuals. Furthermore, intraspecific variations were extracted to find candidate cpDNA markers. Results: The phylogenetic tree showed that Japanese larch forms a monophyletic group, within which Manokami larch can be phylogenetically placed, based on the complete chloroplast genome, with a bootstrap value of 100%. The value of nucleotide diversity (π) was calculated at 0.00004, based on SNP sites for Japanese larch, suggesting that sequences had low variation. However, we found three hyper-polymorphic regions within the cpDNA. Finally, we detected 31 intraspecific variations, including 19 single nucleotide polymorphisms, 8 simple sequence repeats, and 4 insertions or deletions. Conclusions: Using a distant genotype in a northern limit population (Manokami larch), we detected sufficient intraspecific variation for the possible candidates of cpDNA markers in Japanese larch.

scholarly journals Withdrawal Properties of Self-Tapping Screws in Japanese larch (Larix kaempferi (Lamb.) Carr.) Cross Laminated Timber

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 524
Author(s):  
Junhua Xu ◽  
Shuangbao Zhang ◽  
Guofang Wu ◽  
Yingchun Gong ◽  
Haiqing Ren
Keyword(s):  
Regression Model ◽  
Engineering Design ◽  
Wood Species ◽  
Japanese Larch ◽  
Effective Length ◽  
Larix Kaempferi ◽  
Cross Laminated Timber ◽  
The World ◽  
Different Types ◽  
Length Increment

With the increasing popularity of cross-laminated timber (CLT) constructions around the world, there have been attempts to produce CLT using local wood species in different countries, such as Japanese larch (Larix kaempferi (Lamb.) Carr.) in China. Thus, the need to investigate the connection performance also increases to support the design and construction of CLT buildings using local wood species. In this study, the withdrawal properties of three different types of self-tapping screws (STS), with a diameter of 6 mm, 8 mm, and 11 mm, were tested with Japanese larch CLT. The results revealed that the withdrawal strength of STS increased with increasing density and effective length, but decreased with an increasing diameter. With a density increment of 0.05 g/cm3, the withdrawal strength increased by an average of 9.4%. With an effective length increment of 24 mm, the withdrawal strength increased by an average of 1.4%. An empirical regression model was adopted to predict the withdrawal strength of Japanese larch CLT based on the results, which can be used for potential engineering design of CLT connections using STS.

scholarly journals Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

2016 ◽  
Vol 13 (5) ◽  
pp. 1537-1552 ◽  
Author(s):  
Marta Petrillo ◽  
Paolo Cherubini ◽  
Giulia Fravolini ◽  
Marco Marchetti ◽  
Judith Ascher-Jenull ◽  
...  
Keyword(s):  
Picea Abies ◽  
Decay Rate ◽  
Norway Spruce ◽  
Matrix Model ◽  
Rate Constants ◽  
Radiocarbon Dating ◽  
Time Lag ◽  
Larix Decidua ◽  
European Larch ◽  
14C Dating

Abstract. Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1–3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1–3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1–3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y−1 for spruce and to about 0.012 y−1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD. Consequently, the decay of Picea abies and Larix decidua is very low. Several uncertainties, however, remain: 14C dating of CWD from decay classes 4 and 5 and having a pre-bomb age is often difficult (large age range due to methodological constraints) and fall rates of both European larch and Norway spruce are missing.

scholarly journals Upgrading the fuel properties of hydrochar by co-hydrothermal carbonisation of dairy manure and Japanese larch (Larix kaempferi): product characterisation, thermal behaviour, kinetics and thermodynamic properties

2021 ◽  
Author(s):  
Mohammed Aliyu ◽  
Kazunori Iwabuchi ◽  
Takanori Itoh
Keyword(s):  
Thermal Behaviour ◽  
Total Pore Volume ◽  
Dairy Manure ◽  
Fuel Properties ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Mass Ratio ◽  
Fixed Carbon ◽  
Solid Biofuel ◽  
Hydrothermal Carbonisation

AbstractThis study investigated co-hydrothermal carbonisation (co-HTC) of dairy manure (DM) and wood shavings from Larix kaempferi, commonly known as the Japanese larch (JL) to enhance the fuel properties of the resulting hydrochar. The JL was mixed with the DM at 25, 50 and 75 wt.% ratios. Co-HTC was conducted at 260 °C for 20 min. The resulting hydrochars were characterised based on the physicochemical properties and the thermal behaviour. Results showed that the hydrochar solid biofuel properties improved as the ratio of JL was increased. The produced hydrochars were in the region of lignite and closed to the region of the coal with increased fixed carbon, carbon contents and lowered H/C and O/C ratios. Hydrochar with ash content of 7.2 ± 0.5% was obtained at 75 wt.% JL. In addition, the HHV of hydrochar increased remarkably to 26.4 ± 0.02 MJ/kg as the mass ratio of the JL was increased. The surface morphology of the hydrochars were altered and became distinct while the specific surface area (SSA) and the total pore volume (TPV) of the hydrochars increased at increasing the mass ratio of the JL. The surface functional groups were also altered by the co-HTC process. A decline in the combustion performance was observed after the HTC process but improved at 75 wt.% JL after the co-HTC process. The kinetic analysis also revealed that the activation energy decreased after the HTC process but increased to a higher value at 50 wt.% JL after the co-HTC process. Therefore, hydrochar production by co-HTC of DM and JL has proved to be an effective and promising solid biofuel source. Graphical abstract

scholarly journals Long-term bending properties of cross-laminated timber made from Japanese larch under constant environment

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Ryuya Takanashi ◽  
Yoshinori Ohashi ◽  
Wataru Ishihara ◽  
Kazushige Matsumoto
Keyword(s):  
Load Capacity ◽  
Creep Rupture ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Loading Capacity ◽  
Loading Test ◽  
Cross Laminated Timber ◽  
Duration Of Load ◽  
Rupture Behavior

AbstractCross-laminated timber (CLT) has been used extensively in timber construction. CLT panels are typically used in roofs and floors that carry a continuous load, and it is important to examine the long-term loading capacity of CLT. However, studies that focus on the long-term loading capacity of CLT are limited. To this end, we conducted long-term out-of-plane bending tests on seven-layer CLT made from Japanese larch (Larix kaempferi) under constant environmental conditions, investigated creep performance and duration of load, and experimentally analyzed creep rupture behavior. The mean estimated relative creep after 50 years was 1.49. The sample showed a satisfactory resistance to creep as a building material. The duration of load of most of the specimens in this study was shorter than the conventional value of small clear wood specimens. Specimens had a lower duration of load capacity than solid lumber. According to the results of survival analysis, a loading level of 70% or more caused the initial failure of specimens. Creep rupture of most of the specimens occurred at less deflection than displacement at failure in the short-term loading test. Additional studies focusing on the effects of finger joints, transverse layers, and width of a specimen on creep rupture behavior are suggested.

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