Axial variation in the cambium anatomy of Schizolobium parahyba var. amazonicum

Schizolobium parahyba var. amazonicum (paricá) is a promising forest species that has been planted in some states of the Amazon region in Brazil, to meet the demand of the plywood panel industry. The present work involves a study of the variations of the cambium and their impact on derivative tissues at different heights in the stem of S. parahyba var. amazonicum. Except for the tangential diameter of the fusiform initials (DFI) and the width of the xylem cell layer in differentiation (WXD), there was significant statistical variation between the evaluated axial positions for all anatomical parameters of the cambium. A strong positive correlation was noticed between the length of the fusiform initials (LFI) with ray height (RH) [r = 0.79, degree of freedom (DF) = 7, P < 0.05], vessel element length (VL) (r = 0.78, DF = 7, P < 0.05) and fiber length (FL) (r = 0.74, DF = 7, P < 0.05). The results of this study give quantitative support that the LFI is an important prognosis, not only for the VL and FL, but also for the rays, in hardwood species.

Wood anatomy of Cussonia and Seemannaralia (Araliaceae) with systematic and ecological implications

The wood structure of two related African genera, Cussonia Thunb. (15 of 21 species) and the monotypic Seemannaralia R.Vig. (Araliaceae) is examined. The considerable diversity in wood anatomical characters within these taxa is mostly related to environmental factors; taxonomic groupings or phylogenetic relationships seem to be less important. The shortening of vessel elements and fibres, an increase in vessel number per group, a decrease in vessel diameter and a reduction in the number of bars of perforation plates, are associated with the more temperat species. The changes in vessel grouping show a significant correlation with rainfall. The placement of the simple-leaved Cussonia species in the subgenus Protocussonia and the isolated position of C. paniculata Eckl. & Zeyh., the only member of the subgenus Paniculatae, are supported. Many Cussonia species share a very low fibre to vessel element length ratio. Despite the basal position of Seemannaralia relative to Cussonia revealed by molecular data (Plunkett et al. 2004), its wood structure is more specialised in terms of the Baileyan major trends in wood evolution. This discrepancy may be the effect of a long-term adaptation of tropical ancestors of Seemannaralia to drier biomes.

ANATOMIA DA MADEIRA DE Toona ciliata CARACTERÍSTICAS DAS FIBRAS PARA PRODUÇÃO DE PAPEL

A madeira de cedro-australiano, plantado no Brasil visando à produção de serrados, foi caracterizada anatomicamente, avaliando-se os elementos constituintes no sentido medula–casca, além das relações entre as dimensões das fibras, índices indicadores da qualidade da polpa celulósica a ser produzida. Foram utilizados discos retirados do diâmetro à altura do peito (DAP) de cinco árvores com 18 anos de idade. A madeira apresenta cerne e alburno distintos, anéis de crescimento distintos a olho nu, textura fina a média, com brilho e grã regular. O diâmetro tangencial dos poros e a largura dos raios aumentaram no sentido medula casca, ao contrário do número de poros por milímetro quadrado e a quantidade de raios por milímetro, que diminuíram. Os valores médios do comprimento dos elementos de vaso, das fibras, a largura da fibra e o diâmetro do lume aumentaram no sentido medula–casca, sendo que a espessura da parede teve uma pequena variação, mas não significativa estatisticamente. Os valores obtidos para os índices indicativos da qualidade da polpa celulósica não sugerem a madeira de Toona ciliata M. Roem para a produção de papel do tipo embalagem.Palavras chave: Cedro-australiano; características anatômicas; polpa celulósica. AbstractToona ciliate wood anatomy and fiber characteristics for paper production. The Australian cedar wood, planted in Brazil to aim at saw wood production, was anatomically characterized, evaluating the constituent elements variation from pith to bark, as well the relationship between fiber dimensions, index indicating the quality of cellulose produced. Were obtained discs at breast high (DBH) of five trees with 18 years old. The wood has heartwood and sapwood distinct, growth rings distinct without lens, fine to medium texture, with brightness and straight grain. Tangential diameter of vessel lumina and ray width increased from pith to bark; unlike vessels per square millimeter and rays per millimeter that decreased. The mean values of vessel element length, fiber length, fiber width, lumen diameter increased from pith to bark, and fiber wall thickness had a little variation, but not statistically significant. The obtained values for quality pulp indicative index don’t suggest Toona ciliata M. Roem wood for package paper production. Keywords: Australian cedar; anatomic characteristic; cellulose pulp.

Feasibility study of quality plantation pulpwood breeding on fibre length, vessel element length and their ratio sought by within-tree variations in Eucalyptus trees

The relationship between fibre length and vessel element length was examined by their within-tree variations for breeding quality plantation pulpwood from the view points of pulp properties, that is, shorter vessel element and longer fibre are preferable. Because the genetic difference between trees may express the different ratio of fibre length to vessel element length. Within-tree variations in the trunk of fibre length and vessel element length were studied in Eucalyptus camaldulensis and E. globulus trees grown at the same site. Within-tree variations of both cell length properties in both species were generally high in the upper and outer parts of the trunk in both fibre and vessel. No large difference of tendency was observed between individuals and between species except in the axial variation between individuals of E. globulus for vessel element length by statistical analysis. The relationships between fibre length and vessel element length were significant in all trees although the rate of fibre length to vessel element length was significantly different both between individuals in each species and between species. From these, the breeding program is expected to select a tree possessing genetically longer fibre length (more elongation of cambial initial) indicating higher breaking length with shorter vessel element length (shorter cambial initial) indicating higher printability, regardless the difference in the within-tree variations

The endoparasite Pilostyles ulei (Apodanthaceae – Cucurbitales) influences wood structure in three host species of Mimosa

Pilostyles species (Apodanthaceae) are endoparasites in stems of the plant family Fabaceae. The body comprises masses of parenchyma in the host bark and cortex, with sinkers, comprising groups of twisted tracheal elements surrounded by parenchyma that enter the secondary xylem of the host plant. Here we report for the first time the effects of Pilostyles parasitism on host secondary xylem. We obtained healthy and parasitized stems from Mimosa foliolosa, M. maguirei and M. setosa and compared vessel element length, fiber length, vessel diameter and vessel frequency, measured through digital imaging. Also, tree height and girth were compared between healthy and parasitized M. setosa. When parasitized, plant size, vessel diameter, vessel element length and fiber length are all less than in healthy plants. Also, vessel frequency is greater and vessels are narrower in parasitized stems. These responses to parasitism are similar to those observed in stressed plants. Thus, hosts respond to the parasite by changing its wood micromorphology in favour of increased hydraulic safety.

Wood Anatomy of Lecythidaceae Species called “Tauari”

Woods from an important group of Lecythidaceae species called “tauari” can hardly be identified in the field by their gross and general features. In this study we show that, when properly delimited to the genera Allantoma, Cariniana and Couratari, wood anatomical characteristics can be used to identify the species known as “tauari”, even though it is not possible to separate all species. In addition to anatomical characters, wood colour is an important character to help distinguish species of Cariniana and Allantoma from species of Couratari. Detailed wood anatomical descriptions from “tauari” woods Allantoma, Cariniana and Couratari are given and a table with diagnostic differences is presented. Common characters of this group are axial parenchyma in narrow continuous bands, prismatic crystals in chambered axial parenchyma cells and silica bodies in ray cells. Microscopic features that help in species identification are: fibre pitting (minutely or distinctly bordered), traumatic intercellular canals, average vessel diameter, vessel element length, axial parenchyma strand length, and ray height and width.

Effect of fertilization on cell size in wood of Eucalyptus grandis Hill ex Maiden

The use of fertilization in forest stands results in yield gains, yet little attention has been directed to its potential effects on the quality of wood produced. Information is scarce about the effect of fertilization on anatomical structures of older Eucalyptus wood. This work aims to study the effect of fertilization on tissue cell size of wood from a Eucalyptus grandis stand at age 21 years, the management system of which is based on selective thinning and fertilizer application at the start of the thinning season. Factors to consider include: presence or absence of fertilizers, two log positions and five radial (pith to bark) positions. Results led to the conclusion that fertilization significantly influenced only vessel frequency. Vessel element length was influenced by tree height. Fiber length, fiber diameter, fiber wall thickness, vessel element length, vessel diameter and vessel frequency were influenced by the radial position of the sample in relation to the log. A positive correlation was observed between fiber length, fiber diameter, fiber wall thickness, vessel element length, vessel diameter, ray width and radial position, while a negative correlation was observed between ray frequency and radial position.

Radial Variation in the size of Axial Elements in Relation to Stem Increment in Quercus Serrata

In Quercus serrata, radial variations of wood fibre length, earlywood vessel element length, and earlywood vessel lumen diameter were investigated and maturation ages of them were estimated using nonlinear segmented regression analysis as proposed by Peszlen (1994). In addition, the age at the maximum point of current annual increment and mean annual increment were estimated by using the Gompertz growth function fitted to the variation of cumulative ring width with ring number from the pith. In the same radial strip, the maturation ages both of wood fibre length and the earlywood vessel element length were similar, and those were close to the ages at the maximum point of current annual increment, whereas the maturation age of earlywood vessel lumen diameter was generally greater, close to the age at the maximum point of mean annual increment. These results indicate that earlywood vessel lumen diameter is the best indicator of the three anatomical properties tested and that a relationship exists between the maturation ages of the size of axial elements and radial stem increment.

Xylem Vessel Anatomy of Sweet Cherries Grafted onto Dwarfing and Nondwarfing Rootstocks

Xylem vessel anatomy was examined in tissues surrounding the graft union of sweet cherry (Prunus avium L.) scion (stem) and nondwarfing, semi-dwarfing, or dwarfing rootstock (root) combinations, to characterize potential changes in anatomical features during the initial stages of graft union formation. Vessel element length, frequency, diameter, lumen area (LAV), and mean vessel hydraulic diameter (VDh) were examined in `Rainier' (P. avium) scion wood grafted onto nondwarfing `Colt' (P. pseudocerasus L. × P. avium) or `F 12/1' (P. avium) rootstock and semi-dwarfing `Gisela 6' [`Gi 6' (P. cerasus L. × P. canescens L.)], or dwarfing `Gisela 5' [`Gi 5' (P. cerasus × P. canescens)] rootstock systems in: heterograft combinations (commercial scion-rootstock combinations); homografts (scion and rootstock are the same genetic material); and reciprocal heterografts (rootstock tissue grafted onto scion tissue). Vessel element length was not affected by rootstock, but vessel frequency and lumen area in graft union tissues were smaller in `Rainier'/`Gi 5' (dwarfing combination) than in `Rainier'/`Colt' (nondwarfing combination). The heterograft combination of `Rainier'/`Gi 5' had smaller scion LAV, lower VDh and narrower vessels than homograft or reciprocal heterograft combinations. As callus differentiated into vascular elements, xylem rays in `Rainer'/`Gi 5' tended to develop at an acute angle to the longitudinal axis of the tree and there was an increase in nonfunctional phloem in `Rainer'/`Gi 5' compared to `Rainer'/`F 12/1'. Collectively, the data provides further evidence that a combination of smaller and fewer vessels in the scion and graft union, as well as irregular vessel orientations in the vascular tissue within dwarfing combinations could contribute to hydraulic resistance in the graft union resulting in reduced scion growth (dwarfing).