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Compression wood has undesirable properties for structural timber and for paper production. Traditional methods of detecting it are often time consuming and subjective. This study aimed to rapidly and impartially detect compression wood through the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and diffuse reflectance near infrared (NIR) spectroscopy. Compression wood and non-compression wood samples were obtained from young Pinus radiata D. Don trees grown in New Zealand. Longitudinal dimensional changes were measured during drying or water saturation of the samples; lignin and galactose contents were determined using conventional analytical techniques. Chemical composition was here a more reliable discriminator between wood types than longitudinal dimensional changes. It was shown that partial least-squares regression (PLS-R) or discriminatory analysis (PLS-DA) could be used to build models on the training samples that could discriminate between wood types of the independently grown validation samples. Ultimately, both types of spectroscopies could be used to discriminate between compression wood and non-compression wood either through prediction or discriminatory analysis with equal success. Investigation into spectral differences between wood types, including sequential mixtures of wood types, showed that for the mid-IR region absorbance at a well-resolved lignin band could be used to discriminate compression wood from non-compression wood. For NIR, a similar investigation showed that absorbance values at four separate wavenumbers or the 6000-5600 [cm.sup.-1] region of the first derivative spectra were required for that discrimination. It is proposed that if there is a gradual change in the chemical composition of compression wood with its severity, then IR spectroscopy could feasibly be used to rapidly determine compression wood severity. Key words: compression wood, NIR, ATR-FTIR, Pinus radiata, lignin. Certaines proprietes du bois de compression le rendent indesirable pour le bois de charpente et la production de papier. En general, les methodes traditionnelles de detection prennent du temps et sont subjectives. Cette etude vise a detecter rapidement et objectivement le bois de compression au moyen de la spectroscopie infrarouge a transformee de Fourier par reflectance totale attenuee (IRTF-RTA) et de la spectroscopie dans le proche infrarouge (PIR) par reflectance diffuse. Des echantillons de bois de compression et de bois normal ont ete obtenus a partir de tiges de Pinus radiata D. Don croissant en Nouvelle-Zelande. Les variations dimensionnelles dans le sens longitudinal ont ete mesurees durant le sechage ou la saturation en humidite des echantillons; les teneurs en lignine et en galactose ont ete determinees en ayant recours aux techniques analytiques conventionnelles. La composition chimique permettait ici de distinguer de facon plus fiable les types de bois que les variations dimensionnelles dans le sens longitudinal. Il a ete demontre que la regression ou l'analyse discriminante par les moindres carres partiels pouvaient etre utilisees pour construire des modeles en utilisant les echantillons d'entrainement et que ces modeles pouvaient distinguer les differents types de bois des echantillons de validation cultives de facon independante. Ultimement, les deux types de spectroscopie pourraient etre utilises avec autant de succes pour distinguer le bois de compression du bois normal via l'analyse previsionnelle ou discriminante. L'etude des differences spectrales entre les differents types de bois, incluant des melanges sequentiels de types de bois, a montre que l'absorbance dans l'IR moyen d'une bande bien definie correspondant a la lignine pouvait etre utilisee pour distinguer le bois de compression du bois normal. Dans le cas du PIR, une etude similaire a montre que les valeurs d'absorbance a quatre longueurs d'onde differentes, ou la region comprise entre 6000 et 5600 [cm.sup.-1] des spectres en derivee premiere, etaient necessaires pour faire cette distinction. Si la composition chimique du bois de compression evolue graduellement avec la severite, il serait alors possible d'utiliser la spectroscopie IR pour determiner rapidement la severite du bois de compression. [Traduit par la Redaction] Mots-cles : bois de compression, PIR, IRTF-RTA, Pinus radiata, lignine., Introduction Compression wood is formed by gymnosperm (softwood) trees as a reaction to an external environmental stress (or stresses) (e.g., wind, snow, or weight overhang) that forces the stem or [...]

(1[right arrow]3),(1[right arrow])4)-[beta]-Glucans had previously been detected in nonlignified cell wall preparations of only the Poaceae and five other families in the graminoid clade of the Poales (s.l.). Cell walls of vegetative organs of 12 species in nine families of the Poales (s.l.) were examined by immunogold labeling using a monoclonal antibody to (1[right arrow]3),(1[right arrow]4)-[beta]-glucans. Three types of wall-labeling patterns were identified depending on the density of labeling of the nonlignified walls of epidermal and parenchyma cells and the lignified walls of sclerenchyma fibers and xylem tracheary elements: type 1 in Poaceae and Flagellariaceae, type 2 in Restionaceae and Xyridaceae, and type 3 in Cyperaceae and Juneaceae. Type 1 had the heaviest labeling of nonlignified walls and type 2 the heaviest labeling of lignified walls. Type 3 had the least wall labeling, with only very light labeling of nonlignified and lignified walls. No labeling was found over walls of Typhaceae, Sparganiaceae, or Bromeliaceae. The results are discussed in relation to Poales phylogeny. Key words: (1[right arrow]3),(1[right arrow]4)-[beta]-glucan: immunogold labeling; phylogenetics; plant cell walls: Poaceae; Poales; transmission electron microscopy.

The cell walls of forage chicory (Cichorium intybus) leaves are known to contain high proportions of pectic polysaccharides. However, little is known about the distribution of pectic polysaacharides among walls of different cell types/tissues and within walls. In this study, immunolabelling with four monoclonal antibodies was used to map the distribution of pectic polysaccharides in the cell walls of the laminae and midribs of these leaves. The antibodies JIM5 and JIM7 are specific for partially methyl-esterified homogalacturonans; LM5 and LM6 are specific for (1→4)-β-galactan and (1→5)-α-arabinan side chains, respectively, of rhamnogalacturonan I. All four antibodies labelled the walls of the epidermal cells with different intensities. JIM5 and JIM7, but not LM5 or LM6, labelled the middle lamella, tricellular junctions, and the corners of intercellular spaces of ground, xylem and phloem parenchyma. LM5, but not LM6, strongly labelled the walls of the few sclerenchyma fibres in the phloem of the midrib and lamina vascular bundles. The LM5 epitope was absent from some phloem parenchyma cells. LM6, but not LM5, strongly labelled the walls of the stomatal guard cells. The differential distribution of pectic epitopes among walls of different cell types and within walls may reflect the deposition and modification of these polysaccharides which are involved in cell wall properties and cell development. [ABSTRACT FROM AUTHOR]