We quantified structural features and the aboveground biomass of the deciduous conifer, Metasequoia glyptostroboides (Hu and Cheng) in six plantations in central Japan. In order to derive biomass estimates we dissected 14 M. glyptostroboides trees into three structural components (stem wood, branch wood and foliage) to develop allometric equations relating the mass of these components and of the whole tree to diameter at breast height (DBH). We found robust relationships at the branch and whole tree level that allow accurate prediction of component and whole tree biomass. Dominant tree height was similar within five older (>40 years) plantations (27–33 m) and shorter in a 20-year-old plantation (18 m). Average stem diameter varied from 12.8 cm in the youngest stand to greater than 35 cm in the oldest stand.
Metasequoia have relatively compact crowns distributed over the top 30% of the tree although the youngest stand had the deepest crown relative to tree height (up to 38%). At the individual tree level in older stands, 87% of the aboveground biomass was allocated to the stem, 9% to branch wood and 4% to foliage. We found little difference in the relative distribution of above ground biomass among the stands with the exception of lower foliage biomass in larger diameter trees. Total aboveground biomass of the older stands varied twofold, ranging from a maximum of 450 Mg ha−1 in a 42-year-old stand to a minimum of 196 Mg ha−1 in a 48-year-old stand. Total above ground biomass of the 20-year-old stand was 176 Mg ha−1. 相似文献
To clarify the biosynthesis of syringyl lignans and lignan formation by stereoselective coupling of monolignols, formation of (+)-syringaresinol and (+)-pinoresinol inLiriodendron tulipifera were investigated by means of feeding experiments. Following individual administration ofl-[U-14C]phenylalanine and [8-14C]sinapyl alcohol to excised shoots ofL. tulipifera and their subsequent metabolism for 3h, free [14C] lignans and [14C] lignan glucosides were extracted from both of the stems and leaves with methanol and divided into an ether fraction and an aqueous one, respectively. The glucosides were hydrolyzed by a combination of cellulase and-glucosidase to liberate [14C]lignans as aglycones.l-[U-14C]Phenylalanine was incorporated into free (+)-[14C]syringaresinol and its glucosides; the (+)-[14C]syringaresinols in the stems and leaves had 52% enantiomeric excess (% e.e.) and 42% e.e., respectively; and the (+)-[14C]syringaresinol aglycones from the glucosides in the stems and leaves had 20% e.e. and 22% e.e., respectively. Furthermore, [8-14C]sinapyl alcohol was incorporated into (+)-[14C]syringaresinol and its glucosides in the stems. These results suggest that the (+)-enantiomer of syringaresinol was enantioselectively formed from two molecules of sinapyl alcohol inL. tulipifera followed by transformation into the (+)-syringaresinol glucosides, accompanying the formation of racemic syringaresinol by nonselective coupling and the subsequent transformation of the racemate into their glucosides.l-[U-14C]Phenylalanine was incorporated also into free (+)-[14C]pinoresinol and its glucosides with 12%–42% e.e.Part of this paper was presented at the 47th Annual Meeting of the Japan Wood Research Society, Kochi, April 1997 相似文献
This paper details the influence of the length and content of polypropylene (PP) fibers on the physical and mechanical properties of gypsum particleboard (GPB). The length and amount of PP fibers added had a significant effect on the internal bond strength (IB) and the modulus of rupture (MOR) of GPB. The highest IB value was shown at 9 mm length and 9% content of PP fibers. The MOR was highest when the board was made with PP of 12 mm fiber length and 12% content. Suitable contents of PP fibers were advantageous in that they reinforced the properties of GPB so it achieved high performance. In contrast, a high content of PP fibers reduced the IB, MOR, and modulus of elasticity (MOE) of GPB. The thickness swelling was reduced with an increase in PP length and content. It was concluded that the combination of 12 mm length and 12% content or 3mm length and 9% content was optimum for producing good performance of GPB.Part of this paper was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000 相似文献
The formaldehyde off-gassing properties of various wood products were evaluated under environment conditions that simulate
conditions of mobile home. The formaldehyde concentrations observed in the chamber were correlated to the 24-h desiccator
formaldehyde potentials. It was found that 24-h desiccator values did correlate to formaldehyde levels in the chamber at a
given temperature, relative humidity, air change rate, and sample loading. The 24-h desiccator method correlated to each other
for a given wood product. Formaldehyde levels of wood products tested in combination reflected the levels of the highest single
emitter. Formaldehyde concentrations from combinations of particleboards and plywood panels may be predicted from their single
chamber K factor using the modified Hoetjer equation. Double loading of a single wood product did not double the chamber concentration
at the low air change rate and sample loading. Finally, the formaldehyde concentrations observed in the chamber under conditions
that simulated mobile loadings of wood product, air change rate, temperature, and humidity relate to real wood formaldehyde
levels. 相似文献
Diurnal changes in gas exchange and chlorophyll fluorescence were measured in the top canopy leaves of the tropical rainforest tree species, Macaranga conifera (Zoll.) Muell. Arg. during a drought year. Maximum values of net photosynthetic rate (P(n), 10 &mgr;mol m(-2) s(-1)) and stomatal conductance (g(s), 0.2 mol m(-2) s(-1)) were found in east-facing leaves in early morning. After 1000 h, both P(n) and g(s) decreased. Minimum daytime values of P(n), g(s), and photosystem II (PSII) quantum yield (DeltaF/F(m)') were found in horizontally fixed leaves. At a given electron transport rate through PSII (ETR), P(n) was higher in early morning than at midday, suggesting a high rate of photorespiration at midday. We tested the hypothesis that the effect of low leaf temperature (T(leaf)) on P(n) is significant in the early morning, whereas the effect of low g(s) on P(n) predominates at midday. In the early morning, when T(leaf) was increased from 32 to 38 degrees C by artificial heating, P(n) at a given ETR decreased 29%, suggesting that the low T(leaf) was associated with a high P(n). When T(leaf) at midday was decreased from 37 to 32 degrees C by artificial cooling, P(n) increased 22%, but P(n) at a given ETR was higher in early morning than at midday, even at the same low T(leaf) (32 degrees C). This suggests that the rate of photorespiration was higher at midday than in early morning because low g(s) at midday caused a reduction in leaf intercellular CO(2) concentration. We conclude that low P(n) at midday was the result of both a reduction in the photochemical process and an increase in stomatal limitation. 相似文献
Efficiencies of SCAR, CAPS and PCR-RF-SSCP marker production were investigated using two combinations of breeding lines in Brassica oleracea. Published EST sequences of B. oleracea, Brassica rapa, Brassica napus, and Arabidopsis thaliana and newly determined nucleotide sequences of anther cDNA clones from B. oleracea were used for designing primer pairs to amplify genes. The percentage of primer pairs yielding DNA amplification of a single gene was higher in primer pairs of B. oleracea (91%) than those of B. rapa (56%) and A. thaliana (17%). Single DNA fragments amplified by 9% of the primer pairs showed polymorphism as SCAR markers between a broccoli line and a Chinese kale line by agarose-gel electrophoresis. CAPS analysis showed different band patterns in 32% of the same-sized DNA fragments, and PCR-RF-SSCP analysis revealed DNA polymorphism in 52% of those showing no DNA polymorphism by CAPS. In total, 71% of the single DNA fragments were converted to DNA markers. The frequency of DNA polymorphism between parental lines of a cabbage F1 hybrid was lower, 5% by SCAR and 12% by CAPS. However PCR-RF-SSCP analysis revealed DNA polymorphism in 21% of the DNA fragments showing no polymorphism by CAPS. These results suggest that PCR-RF-SSCP analysis enables highly efficient DNA marker production for mapping of genes in Brassica using progeny, even progeny of closely related parents. Analysis of selfed seeds of broccoli F1 cultivars using PCR-RF-SSCP markers indicated that PCR-RF-SSCP analysis is also applicable to seed purity tests. 相似文献
Cytoplasmic male sterile (CMS) plants were obtained by asymmetrical protoplast fusion between red cabbage (fertile) and normal
radish (fertile). The CMS plants showed restriction fragment length polymorphism (RFLP) patterns of mitochondrial (mt) DNA
that were different from those of both parental lines. PCR analysis of mtDNA of the CMS plants and though Southern blot analysis
showed that the mtDNA of the CMS line had the characteristics of the ogura CMS type. The results suggested that the orf138 gene and the ogura type atp6 gene are present in normal fertile cabbage and radish at a low copy level.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
Although root cap cells are an important substrate for microorganisms in the rhizosphere, little attention has been paid to the decomposition of sloughed root cap cells by microorganisms. This study used rice plant callus cells grown on medium containing 13C-labelled glucose as a model material for rice plant root cap cells. Harvested 13C-labelled callus cells (78 atom % 13C) were subjected to decomposition in an aerobic soil microcosm for 56 days. The low cellulose and lignin levels and the disaggregated nature of the callus cells indicated that these cells were an appropriate model material for root cap cells. DNA was extracted from a soil incubated with 12C- and 13C-callus cells and subjected to buoyant density gradient centrifugation to identify bacterial species that assimilated carbon from the callus cells. The stability of the total bacterial communities during the incubation was estimated. Many DGGE bands in light fractions of soil incubated with 13C-callus cells were weaker in intensity than those from soil incubated with 12C-callus cells, and those bands were shifted to heavier fractions after 13C-callus treatment. 13C-labelled DNA was detected from Day 3 onwards, and the DGGE bands in the heavy fractions were most numerous on Day 21. DGGE bands from heavy and light fractions were sequenced, revealing more than 70% of callus- C incorporating bacteria were Gram-negative, predominantly α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Sphingobacteria and Actinobacteria. These species were phylogenetically distinct from the bacteria reported to be present during plant residue decomposition and resident in rice roots. This study indicates that root cap cells are decomposed by specific bacterial species in the rhizosphere, and that these species augment the diversity of rhizospheric bacterial communities. 相似文献
New red leaf tea cultivar 'Sunrouge' (Camellia taliensis × Camellia sinensis), for which an application for registration was made in 2009, is an anthocyanin-rich tea. The anthocyanin content of 'Sunrouge' was the highest among 4 tea cultivars, and was 8.4 times higher than that of 'Yabukita'. We purified and isolated 6 anthocyanins from 'Sunrouge' by chromatography, and identified them by LC/MS/MS and NMR analysis. As a result, the four anthocyanins were identified as delphinidin-3-O-β-D-(6-(E)-p-coumaroyl)galactopyranoside (2), delphinidin-3-O-β-D-(6-(E)-p-coumaroyl)glucopyranoside (3), cyanidin-3-O-β-D-(6-(E)-p-coumaroyl)galactopyranoside (4), and cyanidin-3-O-β-D-(6-(E)-p-coumaroyl)glucopyranoside (5), and the other two were estimated as delphinidin-(Z)-p-coumaroylgalactopyranoside (1), petunidin-(E)-p-coumaroylgalactopyranoside (6). Compound 3 was found in tea for the first time. In general, anthocyanins have various bioactivities, including relieving eyestrain and antioxidative effects, so it is expected that drinking 'Sunrouge' tea brings in similar bioactivities. 相似文献