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S Y Zhang - One of the best experts on this subject based on the ideXlab platform.
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influence of stand density on ring width and Wood density at different sampling heights in black spruce picea mariana mill b s p
Wood and Fiber Science, 2007Co-Authors: Jerome Alteyrac, Alain Cloutier, S Y Zhang, Jeanclaude RuelAbstract:Thirty-six black spruce sample trees were collected from an 80-year-old stand to examine the influence of stand density on selected Wood quality attributes and their variation with sampling height. The stand, naturally regenerated from fire in 1906, was located in Chibougamau, 400 km north of Quebec. Each tree was assigned a local stand density ranging from 1390 to 3590 stems/ha, calculated from the number of neighboring trees. The trees were grouped into three stand density categories (1790, 2700, and 3400 stems/ha). Each sample tree was analyzed by X-ray densitometry, and various ring features including ring width and Wood density were measured for each ring from pith to bark, at three heights (2.4, 5.1, and 7.8m) and ring area and earlyWood proportion were computed. For all features studied, the variation due to sampling height was larger than that due to stand density. The longitudinal variations for ring density and earlyWood density depend largely upon the Wood type (Juvenile Wood or mature Wood). A variation of ring density with sampling height in the stem from 425 to 458 kg/m 3 was observed in Juvenile Wood, but variations with stand density in all the growth ring features studied were small. Notably, it was observed that stand density had more influence on ring width features than on ring density features.
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characterization of Juvenile Wood to mature Wood transition age in black spruce picea mariana mill b s p at different stand densities and sampling heights
Wood Science and Technology, 2006Co-Authors: Jerome Alteyrac, Alain Cloutier, S Y ZhangAbstract:The radial pattern of both maximum ring density and ring area of 36 black spruce trees were used to determine the transition age from Juvenile Wood to mature Wood. The data were obtained by X-ray densitometry and both segmented linear and polynomial regressions were used to point out the age of the Juvenile Wood boundary. Three stand densities (1,790, 2,700 and 3,400 stems/ha) and three sampling heights (2.4, 5.1 and 7.8 m) were studied. Although maximum ring density and ring area presented similar radial patterns, they gave two significantly different results of transition ages. The maximum ring density over-estimated the transition age (17.6 years) in contrast to ring area (14 years). The results show that the transition from Juvenile Wood to mature Wood occurred after 12 years at 7.8 m (versus 13.1 years at a height of 5.1 m, and 17.6 years at 2.4 m). Although transition age occurred later in the high stand density group (21 years), the difference was not significant between the three stand density groups. Nevertheless, transition age remains difficult to determine since no standard definition exists. The transition occurs over years, and most probably a transition Wood exists between Juvenile Wood and mature Wood. Estimation of the Juvenile Wood proportion in volume shows that it remains constant along the stem and it increases with stand density.
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transition from Juvenile to mature Wood in black spruce picea mariana mill b s p
Wood and Fiber Science, 2005Co-Authors: Ahmed Koubaa, Jean Beaulieu, S Y Zhang, Nathalie Isabel, Jean BousquetAbstract:The radial patterns of several intra-ring traits in increment cores of black spruce (Picea mariana (Mill.) B.S.P.) plantation trees were modeled with polynomials to characterize their trends and to estimate the transition age from Juvenile to mature Wood. Wood density, ring width, lateWood density, and lateWood proportion were obtained by X-ray densitometry. Average radial trends were similar to those reported earlier in Picea species. For all traits measured, significant differences were found among diameter classes. Thus, the Juvenile Wood production period varies with growth rate. In addition, transition age for a given diameter class varies, depending on trait. Hence, transition age needs to be defined more precisely, basing it on biological processes.
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Relationships between Wood density and annual growth rate components in balsam fir (Abies balsamea)
Wood and Fiber Science, 2002Co-Authors: Shinya Koga, S Y ZhangAbstract:This study examined relationships of Wood density components with annual growth rate components (or annual ring width components) in Juvenile Wood and mature Wood of balsam fir [ Abies balsamea (L.) Mill.]. The relationships were studied at two different levels: 1) inter-tree level (between trees), and 2) intra-tree level (within a tree). In addition, Juvenile-mature Wood correlations for these characteristics were investigated. Wood density and annual ring width components of individual growth rings were measured by X-ray densitometry. Based on tree averages (at the inter-tree level), Wood density is significantly correlated with its components (earlyWood density, lateWood density) and lateWood percentage in both Juvenile Wood and mature Wood; and earlyWood density and lateWood percentage are the two most important parameters in determining the overall Wood density of the tree. Wood density, however, is not significantly correlated with annual growth rate (ring width) in either Juvenile Wood or mature Wood, although a weakly negative correlation tends to strengthen in mature Wood. This suggests that the relationship between Wood density and annual growth rate in this species may vary with cambial age. Intra-ring Wood density variation (IDV) shows a positive correlation with Wood density traits, lateWood width, and lateWood percentage in both Juvenile Wood and mature Wood, whereas a weakly negative correlation of IDV with ring width and earlyWood width exists in balsam fir. LateWood traits are the most important parameters in determining the intra-ring Wood density uniformity. At the intra-tree level (based on ring averages within a tree), relationships between Wood density components and ring width components are similar to those found between the trees, although some relationships, to some extent, vary with tree. For each Wood density trait, the Juvenile-mature Wood correlation is significant but moderate. For this species, earlyWood density in Juvenile Wood seems to be the best parameter for predicting mature Wood density.
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Differences in Wood properties between Juvenile Wood and mature Wood in 10 species grown in China
Wood Science and Technology, 2001Co-Authors: F. C. Bao, Z. H. Jiang, X. M. Jiang, X. Q. Luo, S Y ZhangAbstract:This study examined the intrinsic differences in various Wood properties between Juvenile Wood and mature Wood in 10 major reforestation species in China. Comparisons between Juvenile Wood and mature Wood were made in both plantation- and naturally-grown trees. Considerable differences in most Wood properties were found both between plantation-grown Juvenile Wood and mature Wood, and between naturally-grown Juvenile Wood and mature Wood. This suggests that Wood properties of plantation-grown trees, to a large extent, depends on their Juvenile Wood contents, and can thus be manipulated effectively through rotation age. In general, the longer the rotation age, the lower the Juvenile Wood content, and the stronger the mechanical properties of the plantation-grown Woods. However, the differences between Juvenile Wood and mature Wood vary with Wood properties and species. In general, Juvenile Wood and mature Wood have less difference in chemical composition than in anatomical and physico-mechanical properties. Compared to the softWoods studied, the hardWoods appear to have less difference between Juvenile Wood and mature Wood.
Alain Cloutier - One of the best experts on this subject based on the ideXlab platform.
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prediction of tracheid length and diameter in white spruce picea glauca
Iawa Journal, 2015Co-Authors: Cyriac Serge Mvolo, Maurice Defo, Martin Claude Ngueho Yemele, Jean Beaulieu, Ahmed Koubaa, Alain CloutierAbstract:The establishment of patterns of radial and longitudinal variations and the development of models to predict the Wood anatomical properties, especially from Juvenile Wood, are of interest for both Wood industry and researchers. Linear regressions were used to predict whole-tree, breast height and mature tracheid length and diameter in white spruce (Picea glauca (Moench) Voss) and the WBE model was used to predict the variation of tracheid diameter. Tracheid length and diameter increased from pith to bark. Tracheid length decreased, while tracheid diameter increased from apex to lower heights. Cambial age was the most important predictor of tracheid length. The final tracheid length models with either a log transformation or a third-order polynomial of cambial age explained 82% of the variation in the whole-tree tracheid length. At breast height, 83% of the variation in the whole tracheid length was explained using the Juvenile value at a cambial age of 3 years. Up to 87% of the variation was explained by the model, including the average value of Juvenile Wood. However, mature Wood tracheid length at breast height could not be predicted from Juvenile Wood. Distance from the apex predicted the tracheid widening in outer rings but failed to predict tracheid expansion of samples collected at fixed cambial ages. The WBE explained 86% of conduit widening in the outer rings. The sampling strategy, i.e. collecting samples longitudinally at a fixed cambial age vs. at a fixed calendar year is important in predicting tracheid diameter.
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variation in Wood quality in white spruce picea glauca moench voss part i defining the Juvenile mature Wood transition based on tracheid length
Forests, 2015Co-Authors: Cyriac Serge Mvolo, Jean Beaulieu, Ahmed Koubaa, Alain Cloutier, Marc J MazerolleAbstract:Estimations of transition age (TA) and Juvenile Wood proportion (JWP) are important for Wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL) and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench) Voss) based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile Wood (JW) was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L) model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature Wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition Wood area.
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genetic control of Wood properties in picea glauca an analysis of trends with cambial age
Canadian Journal of Forest Research, 2010Co-Authors: Jean Beaulieu, Alain Cloutier, Patrick Lenz, John Mackayj MackayAbstract:We investigated the genetic control of Wood properties as a function of cambial age to enable improvement of Juvenile Wood attributes in white spruce (Picea glauca (Moench) Voss). Increment cores were taken from 375 trees randomly selected from 25 open-pollinated families in a provenance–progeny trial repeated on three sites. High-resolution pith-to-bark profiles were obtained for microfibril angle (MFA), modulus of elasticity (MOE), Wood density, tracheid diameter and cell wall thickness, fibre coarseness, and specific fibre surface with the SilviScan technology. Heritability estimates indicated that genetic control of cell anatomy traits and Wood density increased with cambial age, whereas the genetic control of MFA and MOE remained relatively low across growth rings. Wood density, radial cell diameter, cell wall thickness, and specific fibre surface were highly heritable, indicating that significant genetic gains could be expected in tree improvement programs, although cambial age at selection may stro...
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influence of stand density on ring width and Wood density at different sampling heights in black spruce picea mariana mill b s p
Wood and Fiber Science, 2007Co-Authors: Jerome Alteyrac, Alain Cloutier, S Y Zhang, Jeanclaude RuelAbstract:Thirty-six black spruce sample trees were collected from an 80-year-old stand to examine the influence of stand density on selected Wood quality attributes and their variation with sampling height. The stand, naturally regenerated from fire in 1906, was located in Chibougamau, 400 km north of Quebec. Each tree was assigned a local stand density ranging from 1390 to 3590 stems/ha, calculated from the number of neighboring trees. The trees were grouped into three stand density categories (1790, 2700, and 3400 stems/ha). Each sample tree was analyzed by X-ray densitometry, and various ring features including ring width and Wood density were measured for each ring from pith to bark, at three heights (2.4, 5.1, and 7.8m) and ring area and earlyWood proportion were computed. For all features studied, the variation due to sampling height was larger than that due to stand density. The longitudinal variations for ring density and earlyWood density depend largely upon the Wood type (Juvenile Wood or mature Wood). A variation of ring density with sampling height in the stem from 425 to 458 kg/m 3 was observed in Juvenile Wood, but variations with stand density in all the growth ring features studied were small. Notably, it was observed that stand density had more influence on ring width features than on ring density features.
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Effect of radiata pine Juvenile Wood on the physical and mechanical properties of oriented strandboard
Holz als Roh- und Werkstoff, 2006Co-Authors: Alain Cloutier, Rubén A. Ananías, Aldo Ballerini, Robert PechoAbstract:This work analyzes the impact of radiata pine (Pinus radiata D. Don) Juvenile Wood on the physical and mechanical properties of oriented strandboards (OSB). Radiata pine logs were obtained from 10 trees of a 26-year old managed stand located in the 8th Region of Chile. The experimental design considered the proportion of Juvenile Wood and strand orientation as independent variables. OSB panels of 0.4 m×0.4 m×12 mm were produced and tested. The results show that the Juvenile Wood proportion has a significant impact on the physical and mechanical properties of OSB. Strands orientation had a significant impact on all the properties studied with the exception of the modulus of elasticity in bending. However, this impact was small in all cases and would not change panel grade with the exception of linear expansion. In this case, panels made from tangential strands showed a higher linear expansion. According to these results, radiata pine Juvenile Wood can be used for the manufacturing of OSB up to a proportion of 70% of the oven-dry Wood weight without significant losses of the physical and mechanical properties if the Juvenile Wood strands are located in the surface layers.
Simon G Southerton - One of the best experts on this subject based on the ideXlab platform.
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identification of putative candidate genes for Juvenile Wood density in pinus radiata
Tree Physiology, 2012Co-Authors: Simon G SouthertonAbstract:Wood formation is a complex developmental process driven by the annual activity of the vascular cambium. Conifers usually produce Juvenile Wood at young ages followed by mature Wood for the rest of their lifetime. Juvenile Wood exhibits poorer Wood quality (i.e., lower density) compared with mature Wood and can account for up to 50% of short-rotation harvested logs, thus representing a major challenge for commercial forestry globally. Wood density is an important quality trait for many timber-related products. Understanding the molecular mechanisms involved in the regulation of Juvenile Wood density is critical for the improvement of Juvenile Wood quality via marker-aided selection. A previous study has identified several candidate genes affecting mature Wood density in Picea sitchensis (Bong.) Carr.; however, genes associated with Juvenile Wood density in conifers remain poorly characterized. Here, cDNA microarrays containing 3320 xylem unigenes were used to investigate genes differentially transcribed in Juvenile Wood with high (HD) and low density (LD) in Pinus radiata D.Don. In total, 814 xylem unigenes with differential transcription were identified in at least one of two microarray experiments and 73 genes (45 for HD, 28 for LD) were identified in both experiments, thus representing putative candidate genes for Juvenile Wood density. Interestingly, cellulose synthases (PrCesA3, PrCesA11) and sucrose synthase (SuSy), which are involved in secondary cell wall formation, had stronger transcription in Juvenile Wood with HD, while genes functioning in primary wall formation (pectin synthesis, cell expansion and other modifications) were more transcribed in LD Wood. Cell wall genes encoding monolignol biosynthesis enzymes, arabinogalactan proteins, actins and tubulins were differentially transcribed in either HD or LD Juvenile Wood; however, the latter had exclusively greater transcription of genes involved in monolignol polymerization (laccase and peroxidase). The identified candidate genes also included many non-cell-wall genes (transcription factors, environmental-responsive genes, hormone signalling, etc.) and genes with unknown functions, suggesting complex gene pathways in the regulation of Juvenile Wood density. Interestingly, 19 out of 73 candidate genes for Wood density were among the 108 candidate genes previously identified for microfibril angle, and 16 genes appeared to influence both traits in a synergistic manner for Wood stiffness.
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transcriptome profiling of pinus radiata Juvenile Wood with contrasting stiffness identifies putative candidate genes involved in microfibril orientation and cell wall mechanics
BMC Genomics, 2011Co-Authors: Simon G SouthertonAbstract:The mechanical properties of Wood are largely determined by the orientation of cellulose microfibrils in secondary cell walls. Several genes and their allelic variants have previously been found to affect microfibril angle (MFA) and Wood stiffness; however, the molecular mechanisms controlling microfibril orientation and mechanical strength are largely uncharacterised. In the present study, cDNA microarrays were used to compare gene expression in developing xylem with contrasting stiffness and MFA in Juvenile Pinus radiata trees in order to gain further insights into the molecular mechanisms underlying microfibril orientation and cell wall mechanics. Juvenile radiata pine trees with higher stiffness (HS) had lower MFA in the earlyWood and lateWood of each ring compared to low stiffness (LS) trees. Approximately 3.4 to 14.5% out of 3, 320 xylem unigenes on cDNA microarrays were differentially regulated in Juvenile Wood with contrasting stiffness and MFA. Greater variation in MFA and stiffness was observed in earlyWood compared to lateWood, suggesting earlyWood contributes most to differences in stiffness; however, 3-4 times more genes were differentially regulated in lateWood than in earlyWood. A total of 108 xylem unigenes were differentially regulated in Juvenile Wood with HS and LS in at least two seasons, including 43 unigenes with unknown functions. Many genes involved in cytoskeleton development and secondary wall formation (cellulose and lignin biosynthesis) were preferentially transcribed in Wood with HS and low MFA. In contrast, several genes involved in cell division and primary wall synthesis were more abundantly transcribed in LS Wood with high MFA. Microarray expression profiles in Pinus radiata Juvenile Wood with contrasting stiffness has shed more light on the transcriptional control of microfibril orientation and the mechanical properties of Wood. The identified candidate genes provide an invaluable resource for further gene function and association genetics studies aimed at deepening our understanding of cell wall biomechanics with a view to improving the mechanical properties of Wood.
Jean Beaulieu - One of the best experts on this subject based on the ideXlab platform.
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prediction of tracheid length and diameter in white spruce picea glauca
Iawa Journal, 2015Co-Authors: Cyriac Serge Mvolo, Maurice Defo, Martin Claude Ngueho Yemele, Jean Beaulieu, Ahmed Koubaa, Alain CloutierAbstract:The establishment of patterns of radial and longitudinal variations and the development of models to predict the Wood anatomical properties, especially from Juvenile Wood, are of interest for both Wood industry and researchers. Linear regressions were used to predict whole-tree, breast height and mature tracheid length and diameter in white spruce (Picea glauca (Moench) Voss) and the WBE model was used to predict the variation of tracheid diameter. Tracheid length and diameter increased from pith to bark. Tracheid length decreased, while tracheid diameter increased from apex to lower heights. Cambial age was the most important predictor of tracheid length. The final tracheid length models with either a log transformation or a third-order polynomial of cambial age explained 82% of the variation in the whole-tree tracheid length. At breast height, 83% of the variation in the whole tracheid length was explained using the Juvenile value at a cambial age of 3 years. Up to 87% of the variation was explained by the model, including the average value of Juvenile Wood. However, mature Wood tracheid length at breast height could not be predicted from Juvenile Wood. Distance from the apex predicted the tracheid widening in outer rings but failed to predict tracheid expansion of samples collected at fixed cambial ages. The WBE explained 86% of conduit widening in the outer rings. The sampling strategy, i.e. collecting samples longitudinally at a fixed cambial age vs. at a fixed calendar year is important in predicting tracheid diameter.
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variation in Wood quality in white spruce picea glauca moench voss part i defining the Juvenile mature Wood transition based on tracheid length
Forests, 2015Co-Authors: Cyriac Serge Mvolo, Jean Beaulieu, Ahmed Koubaa, Alain Cloutier, Marc J MazerolleAbstract:Estimations of transition age (TA) and Juvenile Wood proportion (JWP) are important for Wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL) and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench) Voss) based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile Wood (JW) was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L) model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature Wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition Wood area.
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genetic control of Wood properties in picea glauca an analysis of trends with cambial age
Canadian Journal of Forest Research, 2010Co-Authors: Jean Beaulieu, Alain Cloutier, Patrick Lenz, John Mackayj MackayAbstract:We investigated the genetic control of Wood properties as a function of cambial age to enable improvement of Juvenile Wood attributes in white spruce (Picea glauca (Moench) Voss). Increment cores were taken from 375 trees randomly selected from 25 open-pollinated families in a provenance–progeny trial repeated on three sites. High-resolution pith-to-bark profiles were obtained for microfibril angle (MFA), modulus of elasticity (MOE), Wood density, tracheid diameter and cell wall thickness, fibre coarseness, and specific fibre surface with the SilviScan technology. Heritability estimates indicated that genetic control of cell anatomy traits and Wood density increased with cambial age, whereas the genetic control of MFA and MOE remained relatively low across growth rings. Wood density, radial cell diameter, cell wall thickness, and specific fibre surface were highly heritable, indicating that significant genetic gains could be expected in tree improvement programs, although cambial age at selection may stro...
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transition from Juvenile to mature Wood in black spruce picea mariana mill b s p
Wood and Fiber Science, 2005Co-Authors: Ahmed Koubaa, Jean Beaulieu, S Y Zhang, Nathalie Isabel, Jean BousquetAbstract:The radial patterns of several intra-ring traits in increment cores of black spruce (Picea mariana (Mill.) B.S.P.) plantation trees were modeled with polynomials to characterize their trends and to estimate the transition age from Juvenile to mature Wood. Wood density, ring width, lateWood density, and lateWood proportion were obtained by X-ray densitometry. Average radial trends were similar to those reported earlier in Picea species. For all traits measured, significant differences were found among diameter classes. Thus, the Juvenile Wood production period varies with growth rate. In addition, transition age for a given diameter class varies, depending on trait. Hence, transition age needs to be defined more precisely, basing it on biological processes.
John F Kadla - One of the best experts on this subject based on the ideXlab platform.
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utilization of polar metabolite profiling in the comparison of Juvenile Wood and compression Wood in loblolly pine pinus taeda
Tree Physiology, 2006Co-Authors: Tingfeng Yeh, Hou-min Chang, Barry Goldfarb, Cameron R Morris, John F KadlaAbstract:Juvenile Wood (JW) of conifers is often associated with compression Wood (CW), with which it is sometimes believed to be identical. To determine whether JW and CW can be distinguished metabolically, we compared gas chromatographic profiles of 25 polar metabolites from rooted cuttings of a single loblolly pine (Pinus taeda L.) clone raised in controlled environment chambers and subject to three treatments: (1) grown erect with minimal wind sway (control); (2) swayed by wind from oscillating fans; and (3) with 30-cm growth increments successively bent at an angle of 45 degrees to the vertical. Profiles were compared by principal component analysis. Substantial increases in abundances of coniferin and p-glucocoumaryl alcohol separated immature JW-forming xylem tissues of the control trees from the CW-forming xylem of the bent and swayed trees.
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Genetic variation and genotype by environment interactions of Juvenile Wood chemical properties in Pinus taeda L.
Annals of Forest Science, 2006Co-Authors: Robert Sykes, John F Kadla, Fikret Isik, Hou-min ChangAbstract:Genetic variation and genotype by environment interaction (G×E) were studied in several Juvenile Wood traits of 11 year-old loblolly pine trees (Pinus taeda L.). Wafer thin (200 µm) samples from Juvenile (ring 3) and transition (ring 8) Wood of 12 mm increment cores were analyzed. Transition Wood had higher α-cellulose content (46.1%), longer fiber (1.98 mm), and higher coarseness (0.34), but lower lignin (29.7%) than Juvenile Wood (cellulose 40.9%, fiber length 1.4 mm, coarseness 0.28 and lignin 30.3%). General combining ability variance for the traits explained 2% to 10% of the total variance, whereas the specific combining ability variance was negligible, except for α-cellulose content in transition Wood (2%). Specific combining ability by site interaction variance explained from 5% (fiber length) to 37% (lignin) of the total variance. Weak individual-tree heritabilities were found for all the traits, except coarseness, which was moderately high in both Juvenile (0.39) and transition Wood (0.30). Full-sib and half-sib family heritabilities of traits ranged 0.29 to 0.72. Genetic correlations of Wood quality traits with volume and stem straightness were weak, while favorable genetic correlations of lignin with cellulose, coarseness and fiber length were observed. Implications on forest tree improvement programs were discussed. heritability / genetic correlation / α-cellulose / coarseness / lignin
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morphological and chemical variations between Juvenile Wood mature Wood and compression Wood of loblolly pine pinus taeda l
Holzforschung, 2006Co-Authors: Jennifer L Braun, Hou-min Chang, Barry Goldfarb, John F KadlaAbstract:To better understand the within-tree variations between Juvenile Wood, mature Wood, and compression Wood, Wood from a 35-year-old mature bent loblolly pine was separated into seven groups by different positions in the tree. Morphological and chemical structure analyses, including fiber quality, X-ray diffraction, sugar and lignin content analysis, as well as nitrobenzene oxidation, ozonation, and advanced NMR spectroscopy, were performed. Fiber properties were significantly different for tree-top Juvenile normal Wood and tree-bottom Juvenile normal Wood, Juvenile normal and mature normal Wood, Juvenile compression and mature compression Wood. However, differences in the chemical structure and composition were less significant within the specific tissues indicated above.
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comparison of morphological and chemical properties between Juvenile Wood and compression Wood of loblolly pine
Holzforschung, 2005Co-Authors: Barry Goldfarb, Hou-min Chang, Ilona Peszlen, Jennifer L Braun, John F KadlaAbstract:In conifers, Juvenile Wood (JW) is always associated with compression Wood (CW). Due to their similar properties, there is a common belief that JW is the same as CW. To resolve whether JW is identical to CW, 24 rooted cuttings of one loblolly pine clone were planted in growth chambers under normal, artificial bending, and windy environments. The results show that the morphology of JW is significantly different from CW. Furthermore, chemical analyses revealed that JW and CW are significantly different in chemical composition. Our results indicate that JW is different from CW, and the Wood formed under a controlled windy environment is a mild type of compression Wood.
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Genetic variation of Juvenile Wood properties in a loblolly pine progeny test
Tappi Journal, 2003Co-Authors: Robert W. Sykes, Fikret Isik, John F Kadla, Hou-min ChangAbstract:Genetic variation was studied in several Juvenile Wood traits of loblolly pine (Pinus taeda L.). Transition Wood (Ring 8) had higher α-cellulose content, average fiber length, and coarseness but lower lignin content than Juvenile Wood (Ring 3). For all of these traits, genetic variation increased from Juvenile Wood to transition Wood. Fourteen loblolly pine full-sib families differed significantly for α-cellulose content, average fiber length, and coarseness but not for lignin content. Weak individual Farad family heritabilities were found for α-cellulose content, average fiber length, and coarseness for the Juvenile Wood. The heritability estimates for the transition Wood were moderately high. Positive genetic correlations of Wood density were found with α-cellulose content, average fiber length, and coarseness. These traits could be genetically improved by selection based on Wood density.
