Genetic variations of wood properties and growth characters of Ko-rean pines from different provenances

Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously dif-ference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.

Geographic variation and provenance selection for bamboo wood properties in Bambusa chungii

Using 3-year-old culms of 8 provenances of Bambusa chungii from Guangdong, Guangxi and Hainan Provinces, the indexes of wood properties, such as fiber dimensions and chemical composition were investigated and analyzed by the methods of Analysis of variance and correlation coefficient to reveal the geographic genetic variation situation. The results showed that there are significant differences between fiber length, fibrin and 1% NaOH extraction contents of B. chungii from 8 provenances; moreover, the fiber length and fiber length/width ratio had a decreasing change pattern with geographic variation from the south to the north in altitude (from high to low in elevation). The heritabilities for fibrin, fiber length, 1% NaOH extractive, lignin and fiber length/width ratio were 0.7, 0.84, 0.54, 0.38 and 0.13, respectively. A significant negative correlation was found between 1% NaOH extraction, benzo-alcohol extraction contents and bamboo culm yield, whereas there was a significant positive correlation between fibrin contents and bamboo wood yield. Besides, a close correlation was detected between fiber dimensions indices and bamboo growth or bamboo wood yield. Finally, three provenances with high qualities and culm yield, i.e. Huaiji, Xinyi and Guilin, were selected as superior sources based on principal component analysis.

Variation of microfibril angle and its correlation to wood properties in poplars

The microfibril angle of seven poplar clones was determined by using X-ray diffraction technique. Microfibril angle, wood basic density, fiber length, fiber width and cellulose content were assessed for every growth ring at breast height for all sample trees. Significant variation in microfibril angle was observed among growth rings. Mean microfibril angle (MFA) at breast height varied from 7.8?to 28?between growth rings with cambial age and showed a consistent pith-to-bark trend of decline an-gles. Analysis of variance also indicated that there were significant differences in wood basic density, fiber length, fiber width and cellulose content between the growth rings, which had an increasing tendency from pith to bark. Correlations between MFA and examined wood properties were predominantly large and significant negative (?0.01), and the coefficients were -0.660 for cellulose content, -0.586 for fiber length, -0.516 for fiber width and -0.450 for wood basic density, respectively. Regression analysis with linear and curve estimation indicated that a quadratic function showed the largest R2 and the least standard error for describing the relationships between microfibril angle and measured wood properties, and the correlation coefficients were over -0.45 (n=125). The results from this study suggested that microfibril angle would be a good characteristic for improvement in the future breeding program of poplars.

Variation analyses of growth and wood properties of Larix olgensis clones in China

The growth traits (tree height, diameter at breast height, and stem straightness degree) and wood properties [wood density (WD), fiber length, fiber width, ash content (AC), lignin content, cellulose content, hemicellulose content (HEC), and holocellulose content] of 208 26-year-old Larix olgensis clones were analyzed. Except for WD and AC, there were significant differences (p < 0.01) for all traits among clones. The phenotypic coefficient of variation and repeatability of all traits were 9.34-35.33% and 0.218-0.930, respectively. Tree height and diameter at breast height showed significant positive correlation; however, the correlation coefficients among growth characteristics and wood properties were mostly not significant. Ten clones (L70, L56, L82, L90, L59, L91, L61, L92, L86, and L64) were selected as excellent clones under a selection rate of 5%, using tree height, diameter at breast height, and stem straightness degree as evaluation indexes, providing genetic gains of 28.69, 17.96, and 0.67%, respectively. Ten clones (L88, L305, L59, L66, L253, L304, L277, L298, L248, and L293) were selected as excellent clones using wood properties as an evaluation index, with a selection rate of 5%, providing genetic gains in WD, fiber length, fiber width, cellulose content, and HEC of 4.14, 3.64, 9.28, 6.77, and 9.61%, respectively. This study provides a theoretical basis for selecting excellent L. olgensis clones.

Age trends and correlations of growth and wood properties in clone of Eucalyptus urophylla × E. grandis in Guangdong, China

We assessed growth traits and wood properties ofDH32-29, a clone of Eucalyptus urophylla x E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences （1% level） on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from -0.03 to -0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year. Correlations between Pilodyn pin penetration and basic density measured on increment cores showed that Pilodyn could rank or group genotypes or sites into density classes, but failure to predict individual tree and individual clone.

Allelic variation in the coumarate 3-hydroxylase gene associated with wood properties of Catalpa fargesii Bur.

Coumarate 3-hydroxylase(C3h)genes participate in the synthesis of lignin and may affect the properties of wood that are important for its commercial value.A better understanding of the natural variation in C3h genes and their associations to wood properties is required to effectively improve wood quality.We used a candidate gene-based association mapping approach to identify CfC3h allelic variants associated with traits that affect the wood properties of Catalpa fargesii.We first isolated the full-length CfC3h cDNA(1825 bp),which was expressed at relatively high levels in xylem according to real time-polymerase chain reaction.In totally,17 common single-nucleotide polymorphisms(minor allele frequency>5%)were identified through cloning and sequencing the CfC3h locus from a mapping population(including 88 unrelated natural C.fargesii individuals collected from main distribution area).Nucleotide diversity and linkage disequilibrium(LD)in CfC3h indicate that CfC3h has low nucleotide diversity(π_(t)=0.0031 andθ_(w)=0.0103)and relatively low LD(within 1800 bp;r^(2)≥0.1).An association analysis identified eight common single-nucleotide polymorphisms(SNPs)(false discovery rate,Q<0.10)and ten haplotypes(Q<0.10)associated with wood properties,explaining 4.92-12.09%of the phenotypic variance in an association population consisted of 125 unrelated natural individuals(The 88 individuals from the mapping population were comprised in the association population).Our study would provide new insight into C3h gene affecting wood quality,and the SNP markers identified would have potential applications in marker-assisted breeding in the future.

Genetic variation and superior provenances selection for wood properties of Larix olgensis at four trials

Larix olgensis,one of the most important timber species in northeastern China,is used for paper making and construction.In this study,10 wood properties(wood density,fiber length,fiber width,fiber length-to width ratio,hemicellulose content,cellulose content,holocellulose content,lignin content,ash content,and carbon content)of 10 provenances of L.olgensis planted at sites of CuoHai(CH),JiaGeDaQi(JGDQ),LiangShui(LS),and Mao'erShan(MES)were analyzed.The results of ANOVA showed that almost traits differed significantly among locations and provenances,with a significant interaction effect.Each trait also differed significant among provenances within sites.The phenotypic and genetic coefficient of variation(PCV and GCV)and provenance heritability(H 2)for wood properties ranged from 1.122 to 27.365%,from 0.564%to 21.113%and from 0.332 to 0.996,respectively.A correlation analysis showed that wood density was significantly negatively correlated with cellulose content and holocellulose content at sites CH,JGDQ,and LS,but were significantly positively correlated at site MES.Wood density was significantly negatively correlated with lignin content at CH and JGDQ,but not at LS and MES.Fiber width(FW)was negatively correlated with the ratio of fiber length(FL)to width across sites,and FW and FL/W were all positively correlated with FL.Lignin content was significantly positively correlated with hemicellulose content at site JGDQ and significantly negatively correlated with cellulose content and with holocellulose content at site MES.Interestingly,carbon content was positively correlated with cellulose content and holocellulose content at CH,but negatively correlated with these two traits at site MES.In a correlation analysis of wood properties with geographic,soil and climatic characteristics at the four sites,wood properties were mainly correlated with latitude and altitude of the site and affected by the average annual precipitation and temperature simultaneously.To select superior pulpwood provenances and high carbon storage provenances,we selected the two best provenances with excellent wood properties for each location based on a multi-trait comprehensive evaluation,which can be used as the preferred materials for the establishment of large-scale plantations in specific locations.

Geographic variation and provenance-selection for bamboo wood properties in Bambusachungii

Using 3-year-old culms of 8 provenances of Bambusa chungii from Guangdong, Guangxi and Hainan Provinces, the indexes of wood properties, such as fiber dimensions and chemical composition were investigated and analyzed by the methods of Analysis of variance and correlation coefficient to reveal the geographic genetic variation situation. The results showed that there are significant differences be- tween fiber length, fibrin and 1% NaOH extraction contents of B. chungii from 8 provenances; moreover, the fiber length and fiber length/width ratio had a decreasing change pattern with geographic variation from the south to the north in altitude （from high to low in ele- vation）. The heritabilities for fibrin, fiber length, 1% NaOH extractive, lignin and fiber length/width ratio were 0.7, 0.84, 0.54, 0.38 and 0.13, respectively. A significant negative correlation was found between 1% NaOH extraction, benzo-alcohol extraction contents and bamboo culm yield, whereas there was a significant positive correlation between fibrin contents and bamboo wood yield. Besides, a close correlation was detected between fiber dimensions indices and bamboo growth or bamboo wood yield. Finally, three provenances with high qualities and culm yield, i.e. Huaiji, Xinyi and Guilin, were selected as superior sources based on principal component analysis.

The Larix kaempferi genome reveals new insights into wood properties

Here,through single-molecule real-time sequencing,we present a high-quality genome sequence of the Japanese larch(Larix kaempferi),a conifer species with great value for wood production and ecological afforestation.The assembled genome is 10.97 Gb in size,harboring 45,828 protein-coding genes.Of the genome,66.8%consists of repeat sequences,of which long terminal repeat retrotransposons are dominant and make up 69.86%.We find that tandem duplications have been responsible for the expansion of genes involved in transcriptional regulation and stress responses,unveiling their crucial roles in adaptive evolution.Population transcriptome analysis reveals that lignin content in L.kaempferi is mainly determined by the process of monolignol polymerization.The expression values of six genes(LkC OMT7,LkC OMT8,LkL AC23,LkL AC102,LkP RX148,and LkP RX166)have significantly positive correlations with lignin content.These results indicated that the increased expression of these six genes might be responsible for the high lignin content of the larches’wood.Overall,this study provides new genome resources for investigating the evolution and biological function of conifer trees,and also offers new insights into wood properties of larches.

Age-related trends in genetic parameters for wood properties in Larix kaempferi clones and implications for early selection

Wood properties are important traits that determine quality of structural wood. With the aim of performing efficient early selection for wood properties we investigated genetic variation in 20 Larix kaempferi clones aged from 4 to 15 years for four quality traits: wood density, wall thickness to lumen area, microfibrillar angle(MFA) and modulus of elasticity(MOE). We observed that age-related trends in overall means varied for differen traits: MFA decreased with the age, while the others generally increased with the age. Phenotypic variance always showed significant differences from the age of 8 years onward, with CVG ranging from 4% to 25%. Also clonal repeatability increased steadily until 9 years old and then kept medium or higher intensity(0.4–0.8). After the age of 6, genetic correlations were generally higher than phenotypic correlations. Estimates of early selection efficiency suggested that the optimal selection age for wood density was at age 5–6 years, while it was 9–10 years for the other traits. In combination with previous results we proposed a comprehensive early selection strategy for larch clonal breeding that involved selection based on nursery rooting ability, phenology, growth traits, and wood properties.

Application of Non-destructive Techniques in Evaluation of Wood Properties

With the increase of wood and wood products demands in the world, non-destructive evaluation techniques of wood are more and more important. This article clarifies the importance and present situation of non-destructive evaluation and introduces some instruments about non-destructive evaluation, and some advice and ideas are put forward.

Research Advancement in Genetic Variation of Wood Properties

The genetic improvement of wood properties is one of the important measures of improving wood quality.To achieve that,forestry and wood scientists have done a great deal of research in expectation to produce more high-quality wood.The paper summarizes the researches on genetic variation and genetic correlation of wood properties and proposes the prospects to conduct the genetic improvement of wood properties.

Wood Properties of Poplar from Stand Affected by Acid Rain

Wood properties from 28 trees (Populus euramericana) selected from healthy and acid rain damaged forest were measured to evaluate the possible impacts on wood quality and utilization. On the heavily damaged location, the pH value of precipitation ranged from 3.7-5.0, and sulfate loading ranged from 20-40 kg·ha-2.y-1. Quantitative and qualitative studies on ring width, physical properties and mechanical properties indicated that changes of wood properties between diseased and healthy poplar occurred. Aci...

Comparative transcriptome analyses reveal candidate genes regulating wood quality in Japanese larch(Larix kaempferi)

We studied the molecular mechanism of the quality traits of wood formation in larch.We used the immature latewood cells of two Japanese larch(Larix kaempferi)clones with significant differences in density and in microfibrillar angle(MFA)as materials to analyze their gene expression profiles.A total of 1735 differentially expressed genes were detected in immature latewood cells of the two clones,among which,971 were up-regulated and 764 were down-regulated.Digital gene expression profiling analysis revealed that genes encoding transcription factor members NAC66 and R2R3-MYB4,microtubule-associated protein,actin-related protein,cell wall protein members,arabinogalactan protein,Fasciclin-like arabinogalactan protein and glycine-rich protein,and several cell-wall-synthesis genes affected wood density and MFA by regulating latewood formation at transcriptional level.Our study results represent a basis for selection of quality traits and genetic improvement of larch wood.

STUDY ON THE EFFECT OF WOOD MOISTURE CONTENT ON PERMEABILITY IN THE HYGROSCOPIC RANGE

In this paper, the relationship was studied bwtween the permeability of Pinus koraiensis. Larix grnelinii. Betula platphylla and Populus davidiana and moisture content of wood in the hygroscopic range. The mathenatical model of variation low has been obtained from the relationship between wood and water, The results are as fellow: (1)The relationsh ip betweed wood permeability and the moisture content is in twice curve function in the hygroscopic rang. (2)There is a peak value in tangential permeability, (3) The number of openings per cm of cross sectionand pit-opening average radii reduces by the increaasing of wood moisture content.

Research Achievements and Trends in Forest Products Science in Indonesia

The supply of logs for wood industries during the period 2004-2008 was 13.5-32 million cubic meters per year. Logs from plantation forest reached about 65%, which was exploited from industrial plantation forest, Perum Perhutani, as a government enterprise, community forest and estate. The changing log supply from natural forest to plantation forest implies changing of wood species, cutting cycle, log diameter and wood properties. Research concerning the utilization of fast growing species, small log diameter, lesser used species and other llignocellulosic material have been intensively done by some research institutes and universities, and were related to wood properties, wood properties enhancement, wood chemistry, bio-composite, wood engineering, and also non-timber forest products.

Picea species from humid continental and temperate marine climates perform better in monsoonal areas of middle latitudes of China

Picea spp.are a prominent component of the boreal,montane,and sub-alpine forests in the Northern Hemisphere,and have substantial economic importance due to their high quality fibre.However,performance and wood properties of the genus have not been systematically evaluated in China.This study aimed to examine genetic variations in growth traits,phenology,and wood properties of 17 Picea species,(three from North America,two from Europe,and 12 from China),in response to specific climate factors using a randomized complete block design in a monsoonal,middle latitude area of China.Results show that all growth traits and wood properties significantly varied among species(P <0.00).Of the 17 species examined,P.abies and P.pungens were the tallest with heights of 2.5 and 1.9 m at 9 years old,respectively,90% and 50% greater than the average heights.Branch length,number,and angles of both P.abies and P.pungens were greater than those of the other species.Heights of P.glauca and P.omorika were20-33% greater than the average.Fast-growing species had high quantities of first lateral branches and large top whorl branch lengths.The taller species exhibited greater tracheid lengths and average tracheid lengths to radial central diameter ratios(TL/R_D2),but smaller cell wall thicknesses to tracheid radial lumen diameter ratios(WT/R_D1),which is favorable for pulp production.Correlation analysis revealed that height and ring width had significant positive correlations with latitude but strongly negative correlations with longitude.Height was positively correlated with average annual rainfalls,but negative correlations with average yearly sunshine.Due to the increased average annual sunshine at the China test site relative to the seed source,species such as P.abies,P.pungens,P.glauca,and P.omorika from wet,humid areas performed better than native species.Considering similar temperatures,precipitation may be the main factor affecting growth,which is beneficial for predicting the extent of spruce expansion.These results should encourage further testing and provide reference information for future exotic species studies in this part of China.

Eucalypt Wood Anatomical and Physical Properties and Their Effects on Plywood Veneer Quality

In order to better understand the reasons why eucalypt veneer checks easily and severely, wood samples of three eucalypt species were selected, and their anatomical and physical properties were examined according to conventional methods and the national standards. The effects of variances in cell wall thickness of wood fibre and vessel, and diameter of the cell lumen as well as the tissue ratio on the quality of plywood veneer were analysed. The results show that： 1） There is a great difference in fibre cell wall thickness and diameter of the cell lumen between early wood and late wood of Eucalyptus delegatensis. 2） E. obliqua has a high wood fibre tissue ratio and the thickest fibre cell wall, but the difference inthe fibre cell wall thickness between early wood and late wood is the smallest. 3） The wood fibre tissue ratio of E. regnans is smaller than that of E. obliqua, and its wood fibre cell wall isthe thinnest and there is only a very small difference in fibre cell wall thickness between early wood and late wood. The difference inthe diameter of wood fibre cell lumen among early wood, transition area and late wood is also small： 4） E. delegatensis has the highest tangential shrinkage rate and radial-tangential shrinkage rate, andE. obliqua has the lowest. It is the variability of wood anatomical properties of these species that cause the difference in the veneer shrinkagei and then affects plywood veneer quality.

Linking molecular deadwood-inhabiting fungal diversity and community dynamics to ecosystem functions and processes in Central European forests

Fungi play vital roles in the decomposition of deadwood due to their secretion of various enzymes that break down plant cell-wall complexes.The compositions of woodinhabiting fungal(WIF)communities change over the course of the decomposition process as the remaining mass of wood decreases and both abiotic and biotic conditions of the wood significantly change.It is currently not resolved which substrate-related factors govern these changes in WIF communities and whether such changes influence the deadwood decomposition rate.Here we report a study on fungal richness and community structure in deadwood of Norway spruce and European beech in temperate forest ecosystems using 454 pyrosequencing.Our aims were to disentangle the factors that correspond to WIF community composition and to investigate the links between fungal richness,taxonomically-resolved fungal identity,and microbial-mediated ecosystem functions and processes by analyzing physico-chemical wood properties,lignin-modifying enzyme activities and wood decomposition rates.Unlike fungal richness,we found significant differences in community structure between deadwood of different tree species.The composition of WIF communities was related to the physico-chemical properties of the deadwood substrates.Decomposition rates and the activities of ligninmodifying enzymes were controlled by the succession of the fungal communities and competition scenarios rather than fungal OTU richness.Our results provide further insights into links between fungal community structure and microbialmediated ecosystem functions and processes.