scholarly journals Bark and Cambial Variation in the Genus Clematis (Ranunculaceae) in Taiwan

2020 ◽  
Author(s):  
Sheng-Zehn Yang ◽  
Po-Hao Chen ◽  
Chien-Fan Chen
Keyword(s):  
Vascular Bundle ◽  
Secondary Xylem ◽  
Vascular Bundles ◽  
Outer Bark ◽  
Axial Parenchyma ◽  
Primary Xylem ◽  
Second Stage ◽  
Morphological Studies ◽  
Key Features ◽  
Sclerenchyma Fibers

Abstract BackgroundStudies on the anatomical characteristics of stems of Taiwanese species from the Clematis genus (Ranunculaceae) are scarce. The aim of this study was to investigate and compare cambial variation in stems of 22 Clematis species. ResultsThe rhytidome (outer bark) was either cogwheel-like or continuous, except for in the species Clematis tashiroi. Key features of the genus were eccentric to elliptical or polygonous-lobed stems, wedge-like phloem, wedge-like rays, indentations in the axial parenchyma, and ray dilatation. The cortical sclerenchyma fibers were embedded in the phloem rays with approximately 23% of the Clematis species. Both C. psilandra and C. tsugetorum had restricted vessels. There were three vascular bundle patterns, with approximately 27% of the Clematis species in Taiwan having 12 vascular bundles. The vessels dispersed throughout the stem were semi-ring-porous in most species, but were ring-porous in others. No species had diffuse-porous vessels. Only two species had a primary xylem ring located around the pith. Secondary xylem rays split the secondary xylem into parts, increasing stem diameter. The developmental stage of each sample was determined, with the initial ring-like periderm being produced in the primary phloem during the second stage. ConclusionsThe cambial variations described in this study provide a foundation for further morphological studies of the Clematis genus.

scholarly journals The stem anatomy of the Clematis species (Ranunculaceae) in Taiwan

2021 ◽  
Author(s):  
Sheng-Zehn Yang ◽  
Po-Hao Chen ◽  
Chien-Fan Chen
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Restriction Pattern ◽  
Vascular Bundles ◽  
Stem Anatomy ◽  
Primary Xylem ◽  
Morphological Studies ◽  
Arc Shape ◽  
Key Features ◽  
Cambial Variants

Abstract Background Studies on the stem anatomical characteristics of Taiwanese species from the Clematis genus (Ranunculaceae) are scarce. This study aimed to investigate and compare the patterns of secondary growth in stems of 22 Clematis species. Results The rhytidome is composed of periderm and non-conducting phloem and formed either cogwheel-like or continuous segment bark. Key features of the genus were stem with an irregular conformation, wedge-like phloem and rays, indentations in the axial parenchyma, ray dilatation, and narrow rays. Approximately eight Clematis species formed bark arc shape, which developed the cogwheel- like rhytidome. There were with approximately 27% of the Clematis species in Taiwan having 12 vascular bundles. The vessels dispersed throughout the stem were semi-ring-porous in most species but were ring-porous in others. No species had diffuse-porous vessels. The vessel restriction pattern was only found in the two shrubs, C. psilandra and C. tsugetorum. The primary xylem ring was located around the pith in C. uncinata var. uncinata, making its pith cavity hexagon in shape. Four species had the pith cavity feature. Narrow rays that occurred in the secondary xylem increased with increasing stem diameter. Conclusions The cambial variants described in this study provide a foundation for further morphological studies of the Clematis genus.

scholarly journals Development of Intra- and Interxylary Secondary Phloem in Coccinia indica (Cucurbitaceae)

IAWA Journal ◽  
2011 ◽  
Vol 32 (4) ◽  
pp. 475-491 ◽  
Author(s):  
Vidya S. Patil ◽  
Carmen R. Marcati ◽  
Kishore S. Rajput
Keyword(s):  
Vascular Bundle ◽  
Secondary Xylem ◽  
Secondary Growth ◽  
Cambial Activity ◽  
Vascular Bundles ◽  
Secondary Phloem ◽  
Stem Anatomy ◽  
Axial Parenchyma ◽  
Vessel Elements ◽  
Coccinia Indica

Stem anatomy and the development of intraxylary phloem were investigated in six to eight years old Coccinia indica L. (Cucurbitaceae). Secondary growth in the stems was achieved by the normal cambial activity. In the innermost part of the thicker stems, xylem parenchyma and pith cells dedifferentiated into meristematic cells at several points. In some of the wider rays, ray cells dedifferentiate and produce secondary xylem and phloem with different orientations and sometimes a complete bicollateral vascular bundle. The inner cambial segments of the bicollateral vascular bundle (of primary growth) maintained radial arrangement even in the mature stems but in most places the cambia were either inactive or showed very few cell divisions. Concomitant with the obliteration and collapse of inner phloem (of bicollateral vascular bundles), parenchyma cells encircling the phloem became meristematic forming a circular sheath of internal cambia. These internal cambia produce only intraxylary secondary phloem centripetally and do not produce any secondary xylem. In the stem, secondary xylem consisted mainly of axial parenchyma, small strands of thick-walled xylem derivatives, i.e. vessel elements and fibres embedded in parenchymatous ground mass, wide and tall rays along with exceptionally wide vessels characteristic of lianas. In thick stems, the axial parenchyma de-differentiated into meristem, which later re-differentiated into interxylary phloem. Fibre dimorphism and pseudo-vestured pits in the vessels are also reported.

scholarly journals RESILIENCE OF FERNS: WITH REFERENCE TO DESICCATION AND REHYDRATION STRESS OFFER NEW INSIGHTS

2017 ◽  
Vol 4 (2) ◽  
pp. 89-94
Author(s):  
Kavitha C.H ◽  
Meenu Krishnan ◽  
Murugan K
Keyword(s):  
Vascular Plants ◽  
Stress Proteins ◽  
Secondary Xylem ◽  
Plant Water Relations ◽  
Vascular Bundles ◽  
Late Cenozoic ◽  
Primary Xylem ◽  
Hydraulic Failure ◽  
Pit Membrane ◽  
Selection For

Ferns are one of the oldest vascular plants in existence and they are the second most diverse group of vascular plants followed to angiosperms. To unravel fern success has focused on the eco-physiological power and stress tolerance of their sporophyte and the gametophyte generations. In this context, those insightsencompass plant water relations, as well as the tolerance to and recovery from drought or desiccation stresses in the fern life cycle are reviewed. Lack of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes.Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and variously sized megaphylls are shared between ferns and more derived lineages, and offer an opportunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Similarly the synthesis and accumulation of sugar, proline and stress proteins along with the production of pool of polyphenols add strength to desiccation stress. Thus, it can possible to suggest that selection acted on the physiology in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic.

scholarly journals WOOD ANATOMY OF THE VANGUERIEAE (IXOROIDEAERUBIACEAE), WITH SPECIAL EMPHASIS ON SOME GEOFRUTICES

IAWA Journal ◽  
2000 ◽  
Vol 21 (4) ◽  
pp. 443-455 ◽  
Author(s):  
Frederic Lens ◽  
Steven Jansen ◽  
Elmar Robbrecht ◽  
Erik Smets
Keyword(s):  
Pacific Ocean ◽  
Wood Anatomy ◽  
Secondary Xylem ◽  
Vessel Diameter ◽  
Underground Structures ◽  
Axial Parenchyma ◽  
Tropical Asia ◽  
Primary Xylem ◽  
The Pacific ◽  
The Pacific Ocean

The Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not homologous; a central pith is found in three species (Fadogia schmitzii, Pygmaeothamnus zeyheri and Tapiphyllum cinerascens var. laetum), while Fadogiella stigmatoloba shows central primary xylem which is characteristic of roots. Comparison of underground versus aboveground wood shows anatomical differences in vessel diameter and in the quantity of parenchyma and fibres.

Observations on Eristophyton Zalessky, Lyginorachis waltonii Calder, and Cladoxylon edromense sp. nov. from the Lower Carboniferous Cementstone Group of Scotland

1987 ◽  
Vol 78 (2) ◽  
pp. 73-84 ◽  
Author(s):  
Albert G. Long
Keyword(s):  
Vascular Bundle ◽  
Secondary Xylem ◽  
Leaf Trace ◽  
Vascular Bundles ◽  
Outer Cortex ◽  
Lower Carboniferous

ABSTRACTFifteen specimens of Eristophyton stems from the Lower Carboniferous Cementstone Group of Berwickshire and East Lothian have been examined. Three possess medullary rays comparable to E. waltonii Lacey, the others have rays like E. beinertianum (Göpp.) Zalessky. In one specimen assigned to E. waltonii a leaf-trace subdivides outside the secondary xylem to form an arc of six separate bundles. Another stem of E. waltonii has attached closely spaced petiole bases one of which is clearly identifiable as Lyginorachis with six vascular bundles arranged in an arc. Stems of Eristophyton from five localities occur associated with petioles or rachises possessing a U-shaped vascular bundle with abaxial ridges like L. waltonii Calder. As these may occur mixed with rachises agreeing with L. brownii Calder the latter is regarded as synonymous. Detached petioles found associated with E. beinertianum may possess four or six basal bundles. The evidence suggests that the U-shaped petiolar bundle passes down into four then six basal bundles and such petioles are associated with both E. waltonii and E. beinertianum. Calder (1935, pl. 1, fig. 2) showed dichotomy in the petiole bundle.In addition different rachises are known possessing a more massive U-shaped bundle but lacking sclerotic nests and sparganum outer cortex. These are assigned to Cladoxylon edromense sp. nov. Cortical nests occur in both E. waltonii and L. waltonii and may be compared with the sclerotic plates in the compressions of Diplotmema dissectum Brongn. and D. patentissimum Ett.. The evidence supports the view that Eristophyton is a pteridosperm with bifurcate fronds known as L. waltonii Calder when petrified and comparable to Diplotmema when compressed.

scholarly journals Sommerxylon spiralosus from Upper Triassic in southernmost Paraná Basin (Brazil): a new taxon with taxacean affinity

2004 ◽  
Vol 76 (3) ◽  
pp. 595-609 ◽  
Author(s):  
Etiene F. Pires ◽  
Margot Guerra-Sommer
Keyword(s):  
Northern Hemisphere ◽  
Secondary Xylem ◽  
Upper Triassic ◽  
New Taxon ◽  
Axial Parenchyma ◽  
Primary Xylem ◽  
Bordered Pits ◽  
The Family ◽  
Paraná Basin ◽  
Parana Basin

The anatoical description of silici?ed Gymnospermae woods from Upper Triassic sequences of southernmost Paraná Basin (Brazil) has allowed the identi?cation of a new taxon: Sommerxylon spiralosus n.gen. et n.sp. Diagnostic parameters, such as heterocellular medulla composed of parenchymatous and sclerenchymatous cells, primary xylem endarch, secondary xylem with dominant uniseriate bordered pits, spiral thickenings in the radial walls of tracheids, medullar rays homocellular, absence of resiniferous canals and axial parenchyma, indicate its relationship with the family Taxaceae, reporting on the first recognition of this group in the Triassic on Southern Pangea. This evidence supports the hypothesis that the Taxaceae at the Mesozoic were not con?ned to the Northern Hemisphere.

10.—Triradioxylon—a New Genus of Lower Carboniferous Petrified Stems and Petioles together with a Review of the Classification of Early Pterophytina

1975 ◽  
Vol 69 (10) ◽  
pp. 231-249 ◽  
Author(s):  
P. D. W. Barnard ◽  
A. G. Long
Keyword(s):  
Vascular Bundle ◽  
Type Species ◽  
New Genus ◽  
Secondary Xylem ◽  
Lower Carboniferous ◽  
Primary Xylem ◽  
Incertae Sedis ◽  
Bordered Pits ◽  
The Family

SynopsisTriradioxylongen. nov. is erected for petrified stems and petioles in which the primary xylem has a triradiate form and possesses protoxylem at the ends of the arms and in the central region. Secondary xylem is dense and composed of small tracheids having multiseriate bordered pits on all walls. Rays are narrow and high. The cortex has sclerotic nests and radial bands of fibres (sparganum structure).In the type speciesT. primaevumsp. nov. the petioles are borne 5–6 cm apart in a phyllotactic spiral of ⅓ on a stem about 1 cm (or more) diameter. The petiole is swollen at its base (about 8 mm diameter) and very gradually tapers to about 2 mm in the rachis which has not been seen to dichotomise. The length of petiole up to the first pinna may exceed 10 cm. Pinnae arose alternately and themselves branched. The T-shaped petiolar bundle has two protoxylem groups at the end of each arm and the central protoxylem divided into three in the rachis.Two detached rachises which cannot be assigned with certainty toTriradioxylon primaevumare placed in the genusLyginorachisand namedL. whitadderensissp. nov. In these the T-shaped vascular bundle is slightly larger than that in the rachises ofT. primaevumand the ends of the transverse arms are wider and may possess three protoxylem groups.The rachises in bothT.primaevumandL. whitadderensisbear alternate triarch pinna-traces but inL. whitadderensisa pair of sub-opposite monarch pinna-traces is also present.Triradioxylonis classified along withButeoxylonin the family Buteoxylonaceae placed tentatively asincertae sedisin the Pteridosperms although showing some affinity withAneurophytonin the Progymnospermopsida.

scholarly journals Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Vascular Bundle ◽  
Plant Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Photochemical Efficiency ◽  
Differentially Expressed ◽  
Vascular Bundles ◽  
Aba Signaling ◽  
Auxin Response

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

scholarly journals Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger and Brasilicereus Backeberg

2007 ◽  
Vol 21 (4) ◽  
pp. 813-822 ◽  
Author(s):  
Patricia Soffiatti ◽  
Veronica Angyalossy
Keyword(s):  
Secondary Xylem ◽  
Sieve Tube ◽  
Vascular Bundles ◽  
Campos Rupestres ◽  
Espinhaço Range ◽  
Diagnostic Characters ◽  
Bordered Pits ◽  
Companion Cells ◽  
Southern Bahia ◽  
Perforation Plates

(Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger wâBrasilicereus Backeberg). Arrojadoa, Stephanocereus and Brasilicereus are endemic Brazilian Cereeae, occurring along the Espinhaço Range, in the campos rupestres, cerrados and caatingas, from northern Minas Gerais to southern Bahia. The genera are columnar, erect to semi-erect cacti, except for one species, A bahiensis, which is globose. This study describes the anatomy of dermal, fundamental and vascular systems, aiming to find diagnostic characters for the genera and species. Basal portions of stems were sectioned transversely and longitudinally, and stained with Astrablue and Safranin. The species share a uniseriate epidermis, with thick cuticle; well developed collenchymatic hypodermis, containing prismatic crystals; cortex with numerous mucilage cells, druses and vascular bundles; outside cortex as a palisade parenchyma; periderm composed of lignified cork cells alternating with suberized cells; pheloderm consisting of a few layers of thin-walled cells; phloem composed of solitary or multiple of two to three sieve tube elements, companion cells, axial and radial parenchyma; secondary xylem with solitary to multiple vessels, with simple perforation plates and alternate bordered to semi-bordered pits; axial parenchyma scanty vasicentric to incomplete; libriform septate fibres; large rays. Unlignified parenchyma is seen in the secondary xylem, varying from a few cells to bands among axial and radial elements. The following are considered diagnostic characters: the shape of lignified phellem cells, cubic to radially elongate, which individualizes S. leucostele; an underdeveloped hypodermis and the occurrence of sclereids in the cortex are exclusive to Brasilicereus markgrqfii.

scholarly journals Mechanical behavior of 'Niagara Rosada' grape berry detachment

2011 ◽  
Vol 31 (6) ◽  
pp. 1115-1122 ◽  
Author(s):  
Daniel Gomes ◽  
Antonio C. de O Ferraz
Keyword(s):  
Mechanical Behavior ◽  
Vascular Bundle ◽  
Traction Force ◽  
Grape Berry ◽  
Vascular Bundles ◽  
Test Results ◽  
Deformation Curves ◽  
Considerable Portion ◽  
Surrounding Skin ◽  
Niagara Rosada

The 'Niagara Rosada' grape is the main Brazilian table grape belonging to the Labrusca family. It develops medium, cylindrical and compact bunches with berries presenting a pinkish skin and a foxy flavor that is valued in the Brazilian market. These berries are tender and have a pedicel-berry connection provided by the vascular bundles and surrounding skin. This cultivar is very susceptible to berry drop mainly caused by vibration and senescence. The objective of this study was to evaluate the temporal mechanical behavior of the pedicel-berry detachment, using resistance indexes extracted from traction force-deformation curves. Test results showed two different detachment types. In the first one, which exhibited higher average resistance, a considerable portion of the vascular bundle came out attached to the pedicel and in the second type; the vascular bundle was retained inside the berry. The proposed indexes based on maximum detachment force, force at 0.2; 0.5; 1.0 and 1.2 mm, and maximum force to corresponding deformation ratio did not discriminate the senescence of the berry.

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