Ray Tracheids Research Articles

Spatial organization and connectivity of wood rays in Pinus massoniana xylem based on high-resolution μCT-assisted network analysis.

Spatial organization and connectivity of wood rays in Pinus massoniana was comprehensively viewed and regarded as anatomical adaptions to ensure the properties of rays in xylem. Spatial organization and connectivity of wood rays are essential for understanding the wood hierarchical architecture, but the spatial information is ambiguous due to small cell size. Herein, 3D visualization of rays in Pinus massoniana was performed using high-resolution μCT. We found brick-shaped rays were 6.5% in volume fractions, nearly twice the area fractions estimated by 2D levels. Uniseriate rays became taller and wider during the transition from earlywood to latewood, which was mainly contributed from the height increment of ray tracheids and widened ray parenchyma cells. Furthermore, both volume and surface area of ray parenchyma cells were larger than ray tracheids, so ray parenchyma took a higher proportion in rays. Moreover, three different types of pits for connectivity were segmented and revealed. Pits in both axial tracheids and ray tracheids were bordered, but the pit volume and pit aperture of earlywood axial tracheids were almost tenfold and over fourfold larger than ray tracheids. Contrarily, cross-field pits between ray parenchyma and axial tracheids were window-like with the principal axis of 31.0μm, but its pit volume was approximately one-third of axial tracheids. Additionally, spatial organization of rays and axial resin canal was analyzed by a curved surface reformation tool, providing the first evidence of rays close to epithelial cells inward through the resin canal. Epithelial cells had various morphologies and large variations in cell size. Our results give new insights into the organization of radial system of xylem, especially the connectivity of rays with adjacent cells.

Evaluation of pit dimensions and uptake of preservative solutions in wood after permeability improvement by bioincising

ABSTRACT Bioincising is a biotechnological process to improve the permeability of wood by biological organisms. In recent years, there has been a great interest to determine the changes in the anatomical structure of wood as a result of bioincising process. In this study, the effects of bioincising by Physisporinus vitreus on the pit structure and permeability of Picea orientalis L. sapwood and heartwood were studied. Bioincised and non-bioincised samples were then treated with micronized copper quaternary and Celcure AC-500 wood preservatives by either dipping or vacuum method. The copper distribution and amount of copper retained in treated wood were evaluated by SEM-EDX and ICP-OES, respectively. The area of copper fixation in treated wood was also measured by the ArcGIS software package. The effects of P. vitreus activity were examined in the wood microstructure after bioincising by light microscope and SEM analyses on radial sections. After the bioincising, a significant increase was observed in the uptake of wood preservatives by vacuum, particularly in heartwood. The measurements on bordered pit, crossfield pit, and ray tracheid bordered pit dimensions in the microstructure of wood indicated that the degradation of pits was the most important factor in improved penetration and uptake of preservative solutions employed.

Comparative Wood Anatomy in Pinaceae with Reference to Its Systematic Position

The wood anatomy of 132 species of the genera Abies, Cathaya, Cedrus, Keteleeria, Larix, Nothotsuga, Picea, Pinus, Pseudolarix, Pseudotsuga and Tsuga was studied to determine the elements that characterise the xylem of each genus and discuss possible groupings by wood anatomy for comparison with clades established by molecular phylogeny. The presence of resin canals and ray tracheids supports the family Pinaceae, although the absence of ray tracheids in Keteleeria and their occasional presence in Abies and Pseudolarix weakens it. Based on wood structure, Pinaceae clearly supports division into two groups, coinciding with molecular phylogeny: Pinoideae (Cathaya-Larix-Picea-Pinus-Pseudotsuga) and Abietoideae (Abies-Cedrus-Keteleeria-Nothotsuga-Pseudolarix-Tsuga). Although differences between genera are slight in Pinoideae, the Abietoideae group presents problems such as the presence of only axial resin canals in Keteleeria and Nothotsuga, absence of ray tracheids in Keteleeria and presence of traumatic radial resin canals in Cedrus. However, other features such as pitted horizontal walls and nodular end walls of ray parenchyma cells, indentures, scarce marginal axial parenchyma and presence of crystals in ray parenchyma strengthen the Abietoideae group.

Variations in bacterial decay between cell types and between cell wall regions in waterlogged archaeological wood excavated in the intertidal zone

Abstract The bacterial decay of waterlogged archeological wood (WAW, hard pine spp.) taken from Daebudo shipwreck No. 2, which was buried in the intertidal zone in the mid-west coast (Yellow sea) of South Korea approximately 800 years ago, was investigated. The maximum moisture content of the outer parts (approx. 3 cm of depth) of WAW was approximately 4.2 times higher than that of undegraded reference pine wood. ATR-FTIR and solid-state 13C-NMR analysis indicated a relative increase of the lignin concentration in WAW caused by the degradation of cellulose and hemicelluloses across the board studied (31-cm-wide and 14.5-cm-thick board). Micromorphological studies also revealed that bacterial degradation was progressed to a depth of 15 cm (vertically 7.3 cm) from the surface, which is the innermost part of the board. Erosion bacteria (EB) were identified as the main degraders of WAW. Degradation by tunneling bacteria (TB) was occasionally detected. Decay resistance to bacterial attacks in WAW varied between cell types and between cell wall regions. Axial tracheids showed less resistance than ray tracheids, ray parenchyma cells, and axial intercellular canal cells, including strand tracheids, subsidiary parenchyma cells, and epithelial cells. Decay resistance was higher in ray tracheids and strand tracheids than in ray parenchyma cells and subsidiary parenchyma-/epithelial cells, respectively. Bordered- and cross-field pit membranes and the initial pit borders showed higher decay resistance than the tracheid cell walls. Overall, the S2 layer of the axial tracheids showed the weakest resistance to bacterial attacks.

Ray Traits of Juvenile Wood and Mature Wood: Pinus massonia and Cunninghamia lanceolata

Ray traits affect secondary xylem development and wood properties. Pinus massonia and Cunninghamia lanceolata, commercially important timber species, were chosen to study the differences in wood ray traits of juvenile versus mature wood. Seven ray traits, i.e., percentage of rays, ray spacing, ray number, uniseriate ray height, fusiform ray height, ray parenchyma cell length and ray tracheid length, as well as eight wood axial tissue traits, were investigated quantitatively. Intraspecific variations in ray traits and axial tissue traits between juvenile wood and mature wood were displayed in violin plots. The results showed that anatomical differences between juvenile wood and mature wood were significant for both ray traits and axial tissue traits. Juvenile wood generally possessed the larger percentage of rays, higher ray spacing and ray number, smaller ray height and shorter ray cells than mature wood. A positive correlation was present between the ray parenchyma cell length and ray tracheid length. Negative correlations of the ray number and ray spacing with uniseriate ray height were found. Additionally, the axial tracheid cell wall thickness all had Pearson’s correlations with ray spacing, ray number and ray parenchyma cell length.

Anatomical structure and degradation characteristics of bioincised oriental spruce wood by Physisporinus vitreus

ABSTRACT Even though oriental spruce (Picea orientalis L.), a common species in the East Black Sea Region of Turkey, is used in a wide range of applications, its wood has low permeability. This study investigated the degradation effects of the bioincising process to improve its treatability with wood preservatives on the microstructure of oriental spruce wood. Test samples were previously subjected to bioincising by Physisporinus vitreus fungus, and the bioincised samples were examined under both a light microscope and scanning electron microscope to observe the effects of the bioincising on the anatomical properties. Bordered pits on the longitudinal tracheid radial walls, piceoid-type cross-field pits, ray tracheid bordered pits, and ray tracheid cell walls in the earlywood and latewood regions within a growth ring were particularly subjected to anatomical evaluations. In the study, the degradation intensity in the samples after the bioincising was well correlated with the weight losses occurred. Splits and factures were determined on the tori of bordered pits on the tracheid cell walls while tears and cracks were present on the pit apertures. The results also show that P. vitreus, a Type I and II white rot fungus, may cause a Type I soft rot.

The first report of Lesbosoxylon Süss & Velitzelos from the early-middle Miocene of eastern Anatolia

A new fossil pine species from eastern Turkey is described and its botanical affinities are discussed. The sample was collected from the city of Kemaliye, Erzincan province, Turkey, and derives from the early-middle Miocene Divriği formation. Transverse, tangential and radial sections were taken from the petrified wood, and its palaeoxylotomical features were investigated. Based on its anatomical features including idioblastic cells in rays a new fossil-species of the genus Lesbosoxylon Süss & Velitzelos was identified as Lesbosoxylon kemaliyensis Akkemik & Mantzouka, sp. nov. Diagnostic features of the new species are: Transition from earlywood to latewood mostly gradual; axial and radial resin canals with thin-walled epithelial cells present; latewood tracheids thin to thick walled; bordered pits on radial walls of tracheids 1-2(-3) seriate; crassulae common; rays heterocellular, uniseriate, partly biseriate; uniseriate rays up to 27 cells high; fusiform rays up to 30 cells high; axial parenchyma occasionally present; ray tracheids 2-3 rows; cell walls of ray tracheids smooth; cross-field pitting pinoid, 1-2(-6) pits per cross-field. Detailed investigation of the botanical affinities of the new fossil wood suggested that the most closely related modern species is Pinus canariensis C. Sm in Buch, a relict species from the Canary Islands.

A new cupressaceous wood from the Lower Cretaceous of central Patagonia reveals possible clonal growth habit

A new genus and species, Austrocupressinoxylon barcinense, based on remains of cupressaceous wood is described for the Lower Cretaceous of central Patagonia, Argentina. The studied specimens are silicified fragments of picnoxylic and homoxylic wood that exhibit a combination of characters not previously reported, therefore a new genus is erected. The characters are: 1- growth ring boundaries distinct, 2- transition from earlywood to latewood gradual, 3- axial parenchyma diffuse,4- radial tracheid pitting predominantly abietinean,5- cross-field pitting cupressoid, arranged in both cupressoid and araucarioid patterns, 6- rays uniseriate heterocellular, 7- end and horizontal walls of ray parenchyma cells smooth or slightly nodular, and 8- ray tracheids with smooth walls. The cross-field pitting patterns and the presence of ray tracheids are two traits of particular interest in the context of systematic affinities. The fragments were collected from two stumps found in life position attached to each other by a main root, consequently, the disposition of the stumps suggests a case of clonal growth by root suckering. This is the second report of such mechanisms in the fossil records worldwide and the first one for South America.

Callixylon wendtiisp. nov., a new species of archaeopteridalean progymnosperm from the Late Devonian of Anti-Atlas, Morocco

ABSTRACTArchaeopterid trees were the main components of most Late Devonian forests. Their aerial axes characterised by a eustele with mesarch primary xylem strands, leaf traces departing radially from cauline bundles and secondary xylem tracheids with radial pits arranged in groups, are referred to the genusCallixylonZalessky. The nineteen species ofCallixylondescribed to date from North America, North Africa, Europe, Xinjiang and several parts of Russia range from the late Givetian to the Mississippian. In this paper, we describe a new species ofCallixylonfrom two specimens collected in the Famennian locality of Mader el Mrakib in eastern Anti-Atlas.Callixylon wendtiisp. nov. is characterised by the presence of sclerotic nests in the pith, a new character for the genus. Its wood shows narrow rays of variable height, with unevenly distributed ray tracheids. Small vascular traces crossing the wood within the two innermost growth rings are interpreted as evidence for short-lived leaves. This discovery adds to the diversity of the genusCallixylonin an area of northern Gondwana that may have been favourable to the establishment of a diverse community of archaeopterid trees.

Surface modification of Norway spruce wood by octadecyltrichlorosilane (OTS) nanosol by dipping and water vapour diffusion properties of the OTS-modified wood

AbstractThe present research deals with a simple dipping method to insert octadecyltrichlorosilane (OTS) into cell walls of spruce wood and to deposit OTS layers on its inner and outer surfaces. Distribution and chemical interactions of OTS with wood polymers has been investigated by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. The OTS/n-hexane solution penetrated into wood via capillary forces through ray tracheids and bordered pits and was deposited as OTS organic-inorganic layers on wood cell walls. The hypothesis is supported by the results, according to which the OTS molecules are hydrolysed by the wood moisture and by free OH groups of the cell wall components. The hydrolysed OTS molecules react with the OH groups and elevate the hydrophobicity of wood.

Pinaceous Wood from the Lower Cretaceous (Barremian—Early Aptian) of California, USA; Lower Chickabally Member, Budden Canyon Formation

Abstract.The Budden Canyon Formation is a Cretaceous unit spanning the Valanginian—Turonian interval in northern California. This marine unit includes plant-fossiliferous near-shore sequences, with richest plant fossil occurrences in the Hauterivian—Aptian. The Lower Chickabally Member (Barremian—early Aptian, ca. 125 Ma) hosts a rich flora preserved anatomically in carbonate concretions, near the town of Ono. The material is dominated by conifers: wood, foliage, cones and dispersed seeds. We characterize the anatomy of a coniferous trunk. The wood exhibits axial and radial resin canals with thick-walled epithelial cells, distinct growth rings, and conspicuous early to late wood transition. Axial tracheids bear radial uniseriate and opposite biseriate pitting. Rays are uniseriate with biseriate portions, with scarce ray tracheids and taxodioid cross-field pitting. Traumatic resin canals form extensive tangential bands. The axial and radial resin canals indicate pinaceous affinities for the Ono wood, but s...

Reaffirming Pinus mundayi as the oldest known pine fossil: REPLY

Reaffirming Pinus mundayi as the oldest known pine fossil: REPLY

Lignified woods of Pinus (Pinaceae) from the late Miocene of central Yunnan, China, and their biogeographic and paleoclimatic implications

Two new species, Pinus uniseriata and P. nanfengensis, were described on the basis of lignified fossil woods from the late Miocene of the Xianfeng Basin (central Yunnan, southwestern China). The woods of both species are characterized by gradual transition from early wood to late wood, predominantly uniseriate pitting in the tracheid walls, the absence of axial parenchyma and traumatic resin canals, the presence of axial and radial resin ducts, uniseriate rays, smooth to slightly pitted ray tracheids and pinoid/taxodioid pits in cross-field pits. They differ in that P. uniseriata wood has unisetiate marginal ray tracheids and taxodioid (occasionally cupressoid) pits whereas P. nanfengensis wood has ray tracheids usually arranged as biseriate, as well as pinoid and taxodioid cross-field pits. The fossil woods showed a considerable anatomical similarity to extant species P. bungeana and P. roxburghii, respectively, which are now absent from central Yunnan. Pinus uniseriata is the first macrofossil record for subsection Gerardianae. Pinus nanfengensis is the first fossil record of the subsection Pinaster outside Europe.

Wood anatomy of Cupressus and its relation to geographical distribution

The wood anatomy of 14 species of Cupressus was studied to determine whether there is a pattern of wood anatomical diversity between the species from the North and Central American (western) region and the Eurasian (eastern) region. Xanthocyparis vietnamensis and Chamaecyparis nootkatensis (syn. Xanthocyparis nootkatensis) were also studied to compare their wood anatomy, given their recent inclusion by some authors in Cupressus. The arrangement of the axial parenchyma, morphology of the transverse end walls of the axial parenchyma, presence of ray tracheids, typology of the end walls of the ray parenchyma cells and ray height support to some extent the division of Cupressus into two large groups: the American group (western region) and the Eurasian group (eastern region), as proposed in molecular phylogenetic studies. The wood anatomy of Chamaecyparis nootkatensis shares the presence of ray tracheids and the same ray typology with American Cupressus, and has the same ray height as Eurasian Cupressus. In contrast, Xanthocyparis vietnamensis shares the absence of ray tracheids and the same ray typology with Eurasian Cupressus, and has the same ray height as American Cupressus.

Pliocene taxodiaceous fossil wood from southwestern Ukraine and its palaeoenvironmental implications

Mineralized wood collected from Late Pliocene strata near Gorbki village in the Transcarpathian region of Beregovo Kholmogor'e in southwestern Ukraine was anatomically studied and identified. The wood possesses distinctive anatomical features and has distinct growth rings with an abrupt transition from early- to late-wood. Wood consists of tracheids with 1–3 seriate, dominating bi-seriate, opposite pits on the radial walls and taxodioid cross-field pitting, indentures present. Rays are uni-seriate and 1 to 73 cells high. Ray parenchyma horizontal walls thin and smooth. Axial parenchyma distributed in early- and late-wood and is solitary and diffuse, with end walls nearly smooth or slightly nodular. The combination of features observed in the wood indicates it belongs to the conifer family Taxodiaceae and is most similar to modern Sequoia and assigned to the fossil genus Sequoioxylon. Comparison with species of Sequoioxylon show it is most similar to Sequoioxylon burejense, but ray tracheids were not found in our specimens. We describe the specimens here as Sequoioxylon cf. s. burejense noting this similarity. Extant Sequoia is distributed in the northern California coastal forest eco-region of northern California and southern Oregon in the United States where they usually grow in a unique environment with heavy seasonal precipitation (2500mm annually), cool coastal air and fog drip. This study supplies magafossil evidence of Sequoioxylon as an element of the Late Pliocene forest community in Ukraine and indicates a climate with heavy seasonal precipitation and fog drip.

A New Species ofTsuga(Pinaceae) based on Lignified Wood from the Late Miocene of Central Yunnan, China, and Its Paleoenvironmental Implications

AbstractA new species,Tsuga nanfengensissp. nov. (Pinaceae), is described on the basis of lignified fossil wood from the late Miocene of the Xianfeng Basin, central Yunnan, southwestern China. Detailed observation of the fossil wood specimens show the following characteristics: distinct growth rings, absence of resin canals, uniseriate bordered pits in the radial wall of tracheids, ray tracheids and piceoid and cupressoid cross‐field pits. These features indicate similarities to the wood of extantTsuga canadensis, T. chinensis, andT. dumosa. According to the fossil record,Tsugawas present in Xundian County during the Miocene. TodayTsugais drought intolerant, preferring wet conditions with no extant species growing naturally in Xundian County. The presence ofTsugain the Miocene of Xundian County indicates a humid climate consistent with previous palaeoclimatic reconstructions showing a wetter and probably shorter dry season in the Miocene, relative to the present day. Therefore, the change in the local climate such as increasing aridity through the Miocene might explain the local extinction ofTsugafrom central Yunnan.

Cytochemical and immunocytochemical characterization of wood decayed by the white rot fungus Pycnoporus sanguineus I. preferential lignin degradation prior to hemicelluloses in Norway spruce wood

Degradation of lignin and non-cellulosic polysaccharides (pectins and hemicelluloses) in Norway spruce wood (softwood) by the white rot fungus Pycnoporus sanguineus was investigated using transmission electron microscopy coupled with immunocytochemistry. P. sanguineus produced selective decay in xylem cells including tracheids, ray tracheids and ray parenchyma cells. Lignin was preferentially removed first from cell walls with hemicelluloses (xylan and mannan) and cellulose remaining. Lignin in compound middle lamella (CML) regions of tracheids was also preferentially degraded prior to degradation of xyloglucan (hemicellulose). This differs from the previous concept of wood decay by selective white rot fungi demonstrating concomitant degradation of lignin and hemicelluloses. In contrast, no clear preferential degradation of lignin prior to pectins and hemicelluloses was observed in middle lamella cell corner (MLcc) regions of tracheids which were the last regions to be attacked by the fungus. Micromorphologically, prominent cell separation between tracheids by delignification of CML regions before complete degradation of secondary cell walls was observed as evidence of selective decay. Variations in resistance to decay by the fungus depending on cell wall orientation (radial vs. tangential) of tracheids and between cell types were also observed.

Phylogenetic Analysis of Pines Based on Chloroplast trnT-trnL Intergenic Spacer DNA Sequences

This study was conducted to distinguish the pines that are too similar to differentiate using conventional methods. Pinus densiflora and Pinus sylvestris have similar anatomical structure. They both have window-like pits and dentate ray tracheids, so it is not easy to distinguish the plants. We tried to find molecular markers by comparing chloroplast DNA sequences to differentiate the pines growing in Korea. We used P. densiflora, P. densiflora for. multicaulis, P. sylvestris, P. rigida, P. rigitaeda, P. koraiensis, and P. bungeana for this study. We found that the non-coding intergenic region of trnT(UGU) and trnL(UAA) genes have differences among the species. We designed a primer set to amplify the region efficiently and compared the PCR product sequences using CLC Workbench programs to find the polymorphism. We could distinguish the species using the sequences of the amplified region and the sequences were reproducible from the pines collected in Korea.

Identifikace fosilních kmenů z lokality Bükkábrány, nyní uložených v přírodní paleontologické rezervaci v Ipolytarnóci v severním Maďarsku

The Late Miocene forest was discovered in the opencast lignite mine of Bükkábrány which is situated in the foothills of the Bükk Mountains (NE Hungary). Sixteen stumps were exposed upright in 2007 at their original position. Five stumps were installed in the Ipolytarnóc Fossils Nature Reserve. They are identified in the present paper. The wood of one fossil trunk (No. 1) has been identified as Glyptostroboxylon rudolphii, which represents the wood of Glyptostrobus. Its main microscopic features are: visible growth rings, gradual transition between early- and late wood, rather small opposite bordered pits in 1–2 loosely spaced vertical rows with infrequent crassulae, uniseriate rays formed of procumbent cells without ray tracheids, 1–3 “glyptostroboid” cross-field pits per field and resin canals absent. The four remaining stumps (Nos. 2–5) have been identified as Taxodioxylon germanicum.. Their main microscopic features are: growth rings, abrupt transition between early- and late wood, opposite bordered pits in 1–3 regular vertical rows with frequent crassulae, uniseriate rays formed of procumbent cells without ray tracheids, 1–3 taxodioid cross-field pits per field arranged mostly in one horizontal row, axial parenchyma both in early and late wood (diffuse arrangement) with smooth transverse end walls and resin canals absent. This species most probably represents the wood of Sequoia.

Lignification of ray parenchyma cells in the xylem of Pinus densiflora. Part I: Microscopic investigation by POM, UV microscopy, and TOF-SIMS

Abstract The lignification process from sapwood (sW) to heartwood (hW) in ray parenchyma cells (Pray) of Pinus densiflora has been analyzed by means of ultraviolet (UV) microscopy, acetyl bromide (CH3COBr) lignin determination, and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The cell wall layers were localized by polarized optical microscopy (POM). POM revealed that Pray have almost no secondary wall in sW and have only the outer layer of secondary wall (S1) in the transition zone (TZ) and hW. UV microscopic observations indicated that the secondary wall of Pray, which is in contact with ray tracheids (Trray), begins to lignify in sW, while the secondary wall of Pray, which is not in contact with Trray, is partially lignified in the TZ. The secondary wall of both types of Pray is completely lignified in hW. The CH3COBr lignin content in sW is slightly lower than that in hW. In the TOF-SIMS measurements, the relative intensities of the secondary ions of guaiacyl-lignin (G-lignin) in the rays in sW are significantly lower than those in hW.