scholarly journals Enhanced Summer Planting Survival of Japanese Larch Container-Grown Seedlings

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1115
Author(s):  
Hisanori Harayama ◽  
Hiroyuki Tobita ◽  
Mitsutoshi Kitao ◽  
Hirokazu Kon ◽  
Wataru Ishizuka ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Mass Production ◽  
Survival Rates ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
High Potassium ◽  
Seedling Traits ◽  
Potassium Fertilization ◽  
Nursery Practices ◽  
Drought Hardening

A previous study revealed low survival rates for Japanese larch (Larix kaempferi) summer-planted seedlings grown in Hiko-V-120 containers. This study examines nursery practices that could potentially prevent deterioration of the seedling water balance after planting to improve the survival rate of this species, which has a low drought tolerance. During summer planting, we tested (1) drought hardening or high-potassium fertilization for two months before planting, (2) antitranspirant or topping treatment at planting, and (3) the use of the JFA-150 container with a larger capacity and lower growing density than the Hiko-V-120 container. Drought hardening increased seedling drought tolerance because of the low leaf:root ratio, due to lower leaf mass production, resulting in increased survival from 74% to 93% in Hiko-V-120 containers. When JFA-150 containers were used, the leaf:root ratio was lower because of higher root mass, resulting in an increase in survival to 87%, with the highest survival of 97% when combined with drought hardening. The application of antitranspirant increased survival to over 90%, whereas topping did not, probably because of severer competition from weeds. High-potassium fertilization did not affect seedling traits or survival. For better survival of summer-planted container-grown Japanese larch seedlings, it is recommended that they be grown in containers providing sufficient cell volume and density for root growth while the seedlings are in the nursery and that irrigation be withheld for two months before planting. In addition, to obtain higher survival, an antitranspirant can be applied at planting at a cost.

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 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.

scholarly journals Genetics of Germination and Seedling Traits under Drought Stress in a MAGIC Population of Maize

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1786
Author(s):  
Soumeya Rida ◽  
Oula Maafi ◽  
Ana López-Malvar ◽  
Pedro Revilla ◽  
Meriem Riache ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Genome Wide Association Study ◽  
Genetic Regulation ◽  
Breeding Programs ◽  
Seedling Traits ◽  
Genome Wide ◽  
A Genome ◽  
Positive Correlations ◽  
Genomic Regions ◽  
Magic Population

Drought is one of the most detrimental abiotic stresses hampering seed germination, development, and productivity. Maize is more sensitive to drought than other cereals, especially at seedling stage. Our objective was to study genetic regulation of drought tolerance at germination and during seedling growth in maize. We evaluated 420 RIL with their parents from a multi-parent advanced generation inter-cross (MAGIC) population with PEG-induced drought at germination and seedling establishment. A genome-wide association study (GWAS) was carried out to identify genomic regions associated with drought tolerance. GWAS identified 28 and 16 SNPs significantly associated with germination and seedling traits under stress and well-watered conditions, respectively. Among the SNPs detected, two SNPs had significant associations with several traits with high positive correlations, suggesting a pleiotropic genetic control. Other SNPs were located in regions that harbored major QTLs in previous studies, and co-located with QTLs for cold tolerance previously published for this MAGIC population. The genomic regions comprised several candidate genes related to stresses and plant development. These included numerous drought-responsive genes and transcription factors implicated in germination, seedling traits, and drought tolerance. The current analyses provide information and tools for subsequent studies and breeding programs for improving drought tolerance.

Compatible taper and stem volume equations for Larix kaempferi (Japanese larch) species of South Korea

2017 ◽  
Vol 14 (7) ◽  
pp. 1341-1349 ◽  
Author(s):  
Nova D. Doyog ◽  
Young Jin Lee ◽  
Sun Joo Lee ◽  
Jin Taek Kang ◽  
Sung Yong Kim
Keyword(s):  
South Korea ◽  
Japanese Larch ◽  
Stem Volume ◽  
Larix Kaempferi ◽  
Larch Species ◽  
Volume Equations

scholarly journals The Maize Clade A PP2C Phosphatases Play Critical Roles in Multiple Abiotic Stress Responses

2019 ◽  
Vol 20 (14) ◽  
pp. 3573 ◽  
Author(s):  
Zhenghua He ◽  
Jinfeng Wu ◽  
Xiaopeng Sun ◽  
Mingqiu Dai
Keyword(s):  
Drought Tolerance ◽  
Stress Responses ◽  
Transgenic Arabidopsis ◽  
Expression Patterns ◽  
Survival Rates ◽  
Wild Type ◽  
Multiple Stresses ◽  
Core Components ◽  
Leaf Water Loss ◽  
Natural Variations

As the core components of abscisic acid (ABA) signal pathway, Clade A PP2C (PP2C-A) phosphatases in ABA-dependent stress responses have been well studied in Arabidopsis. However, the roles and natural variations of maize PP2C-A in stress responses remain largely unknown. In this study, we investigated the expression patterns of ZmPP2C-As treated with multiple stresses and generated transgenic Arabidopsis plants overexpressing most of the ZmPP2C-A genes. The results showed that the expression of most ZmPP2C-As were dramatically induced by multiple stresses (drought, salt, and ABA), indicating that these genes may have important roles in response to these stresses. Compared with wild-type plants, ZmPP2C-A1, ZmPP2C-A2, and ZmPP2C-A6 overexpression plants had higher germination rates after ABA and NaCl treatments. ZmPP2C-A2 and ZmPP2C-A6 negatively regulated drought responses as the plants overexpressing these genes had lower survival rates, higher leaf water loss rates, and lower proline accumulation compared to wild type plants. The natural variations of ZmPP2C-As associated with drought tolerance were also analyzed and favorable alleles were detected. We widely studied the roles of ZmPP2C-A genes in stress responses and the natural variations detected in these genes have the potential to be used as molecular markers in genetic improvement of maize drought tolerance.

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