scholarly journals Cretaceous origin of dogwoods: an anatomically preservedCornus(Cornaceae) fruit from the Campanian of Vancouver Island

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2808 ◽  
Author(s):  
Brian A. Atkinson ◽  
Ruth A. Stockey ◽  
Gar W. Rothwell
Keyword(s):  
Vascular Tissue ◽  
Divergence Time ◽  
Vancouver Island ◽  
Vascular Bundles ◽  
Crown Group ◽  
Outer Periphery ◽  
Secretory Cavities ◽  
Fossil Fruit ◽  
Fruit Characters ◽  
Microscope Slides

BackgroundCornaceae consists of 58 species, all within the genusCornus. The Cenozoic record ofCornusis extensive and well documented. Molecular divergence-time studies suggest that crown-groupCornusmay have originated by the Late Cretaceous. However, there has been no formal report ofCornusfrom Cretaceous deposits. Here, we characterize a permineralized fossil fruit assignable toCornussubg.Cornusfrom the Upper Cretaceous (Campanian) Shelter Point locality of Vancouver Island, British Columbia, Canada.MethodsSerial sections of the specimen were made using the cellulose acetate peel technique. Peels were mounted onto microscope slides and studied by light microscopy.ResultsThe fossil fruit consists of a tri-locular woody endocarp with dorsal germination valves. The locules are sub-triangular to ellipsoidal in transverse section and are separated by thin septa. Endocarp tissue consists of elongated and isodiametric sclereids and secretory cavities. Internal vascular tissue was not observed, but is interpreted to have been located along the outer periphery of the septa for some length, common in many cornalean taxa. There is one seed in each locule, one of which was found to have endosperm and a dicotyledonous embryo.DiscussionWoody endocarps with germination valves, without central vascular bundles, and with one seed per locule are characteristic of several families within the order Cornales. The interpreted vascular pattern and presence of secretory cavities indicates that the fossil fruit is assignable toCornussubg.Cornus. Comparative analysis suggests that the fossil is most similar toCornus piggae, a species described from the Paleocene of North Dakota. This fossil is the first evidence of crown-group Cornaceae from the Cretaceous and sheds light on both the plesiomorphic fruit characters and the timing of the initial diversification of the family and basal asterid lineage, Cornales.

scholarly journals Characteristics of the proximal to distal regions of the petioles to identify 15 tree species of Papilionoideae-Fabaceae

1970 ◽  
Vol 14 (2) ◽  
pp. 101-115 ◽  
Author(s):  
Samia Heneidak ◽  
Abdel Samai M Shaheen
Keyword(s):  
Tree Species ◽  
Transitional Zone ◽  
Vascular Supply ◽  
Vascular Bundles ◽  
Sophora Japonica ◽  
Secretory Cavities ◽  
Plant Taxon ◽  
Sophora Davidii ◽  
Vascular Trace ◽  
Stem Leaf

Comparative studies on the structure of the vascular supply of stem-leaf transitional zone of the petioles were carried out in 15 papilionoid tree species. Anatomical characteristics and changes in the main vascular trace were recorded. The anatomical features of significance include outline; epidermal cell; pericyclic fiber patterns; main petiolar vasculature; presence, number and separation of ridge vascular bundles; presence of additional accessory ridge bundles; crystal types; secretory elements and multicellular trichomes. Erythrina variegata and Pterocarpus indicus show no change in the petiole trace structure throughout their petioles from proximal to distal, while the rest of the species have minor to major changes. Sophora secundiflora has the highest number of ridge vascular bundles (5-6), while these are absent in the two Dalbergia species, E. variegata, Derris robusta, Sophora davidii and S. japonica. Only Derris robusta and Sophora japonica show unusual petiole trace structure by having two additional accessory ridge bundles adaxial of the main trace enclosing with it by a complete ring of pericyclic fibers. The studied species of tribe Millettieae show the presence of secretory cavities lined by epithelial cells. The usefulness of these character states is shown for assessing, identifying and delimiting these examined species. Key words: Accessory ridge bundles, Crystals, Papilionoideae, Petiole anatomy, Petiole vasculature, Ridge bundles, Secretory cavities DOI: 10.3329/bjpt.v14i2.530 Bangladesh J. Plant Taxon. 14(2): 101-115, 2007 (December)

Morphology, anatomy, phylogenetics and distribution of fossil and extant Trochodendraceae in the Northern Hemisphere

2020 ◽  
Author(s):  
Steven R Manchester ◽  
Zlatko Kvaček ◽  
Walter S Judd
Keyword(s):  
Northern Hemisphere ◽  
Late Cretaceous ◽  
Morphological Characters ◽  
Basal Part ◽  
Parsimony Analysis ◽  
Crown Group ◽  
Modern Species ◽  
The Family ◽  
New Material ◽  
Fossil Fruit

Abstract We present the oldest known occurrences of crown-group Trochodendraceae based on new material from the Palaeocene of Wyoming, USA. Two genera are recognized, Trochodendron and Eotrochion gen. nov. The fossil fruit of Trochodendron infernense sp. nov. is represented by a pedicellate, apically dehiscent capsular fruit composed of nine follicle-like units, each bearing a persistent convex style. The basal part is ornamented with numerous raised stamen scars. From the same deposits, Eotrochion is represented by infructescences, fruits and associated leaves. The infructescences are racemes of numerous apically dehiscent capsules, each with c. 14–16 styles, each with an underlying nectary and receptacles lacking stamen scars, but possessing a prominent perianth scar. A phylogenetic assessment of the modern species, plus representatives of four extinct genera of fossil Trochodendraceae based on available morphological characters, yields a favoured topology of Trochodendron(Eotrochion(Concavistylon kvacekii(C. wehrii (Pentacentron, Tetracentron)))). A parsimony analysis of currently available characters indicates that C. wehrii renders Concavistylon non-monophyletic. Accordingly, we transfer it to Paraconcavistylon gen. nov., characterized by pendent, rather than erect infructescences. We also reconsider the extinct Nordenskioeldia (Late Cretaceous to Miocene), the prior placement of which in Trochodendraceae has been challenged, and we consider it to fall outside the crown group of the family.

Early ontogeny defines the diversification of primary vascular bundle systems in angiosperms

2020 ◽  
Author(s):  
Regine Claßen-Bockhoff ◽  
Doris Franke ◽  
Hansjörg Krähmer
Keyword(s):  
Vascular Bundle ◽  
Vascular Tissue ◽  
Three Dimensional ◽  
Early Ontogeny ◽  
Leaf Primordia ◽  
Dimensional System ◽  
Vascular Bundles ◽  
Histological Data ◽  
Molecular Aspects ◽  
The One

Abstract Understanding vascular bundle systems in angiosperms is a challenge. On the one hand, the vascular tissue is extremely important in reconstructing the evolution and survivability of plants, but on the other hand, it forms a complicated three-dimensional system of controversially discussed phylogenetic and ontogenetic origin. To increase clarity, in this paper we briefly summarize histological, phylogenetic and molecular aspects of primary vascular bundle formation in angiosperms, adding histological data on early stages of vascular bundle formation, proposing a concept combining the different views and providing simplified illustrations to improve the understanding of primary vascular systems in angiosperms. Based on the auxin hypothesis, vascular bundle formation is stimulated by the development of leaf primordia. Provascular domains appear at the base of the leaf primordia and develop into two directions (leaf, internode). The low vs. high number of internodal bundles, their circular vs. scattered arrangement and the open vs. closed bundle construction in eudicots vs. monocots can be deduced to be due to processes below the shoot apical meristem. The most important processes distinguishing monocots from eudicots are the isolated bundle initiation outside the primary meristem, the enormous expansion of the leaf bases associated with a high number of vascular bundles and the early onset of primary thickening passively dislocating vascular bundles.

STRUCTURAL DAMAGE AND GALL INDUCTION BY PEGOMYA CURTICORNIS AND PEGOMYA EUPHORBIAE (DIPTERA: ANTHOMYIIDAE) WITHIN THE STEMS OF LEAFY SPURGE (EUPHORBIA × PSEUDOVIRGATA) (EUPHORBIACEAE)

1990 ◽  
Vol 122 (3) ◽  
pp. 429-439 ◽  
Author(s):  
Andre Gassmann ◽  
Joseph D. Shorthouse
Keyword(s):  
Structural Damage ◽  
Vascular Tissue ◽  
Leafy Spurge ◽  
Feeding Strategies ◽  
Vascular Bundles ◽  
European Origin ◽  
Gall Induction ◽  
Vascular Connections ◽  
Herbaceous Perennial ◽  
Thick Layers

AbstractLeafy spurge (Euphorbia × pseudovirgata [Schur]) is an herbaceous perennial and serious weed of European origin that has been accidently introduced into North America. The European anthomyiid flies Pegomya curticornis (Stein) and Pegomya euphorbiae (Kieffer) are found on several spurge species in Europe and also attack leafy spurge. The two flies induce identical galls on the subterranean stems of their host plants, and the shoots wilt and die. Eggs are laid on the shoot tip, and the larvae bore into the stem by eating pith which is later replaced by callus. This is a rare example of an insect with both boring and gall-inducing feeding strategies. Galls are induced when larvae feed on the ring of vascular tissue. There is no proliferation of nutritive cells but instead thick layers of gall parenchyma are produced. The vascular connections are broken at the gall level and concentric vascular bundles appear in the cortical and gall parenchyma. After pupation an inner periderm differentiates around the chamber surface.

scholarly journals First Report of Fusarium oxysporum f. sp. lycopersici Race 3 Causing Fusarium Wilt on Tomato in Korea

Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1377-1377 ◽  
Author(s):  
H.-W. Choi ◽  
S. K. Hong ◽  
Y. K. Lee ◽  
H. S. Shim
Keyword(s):  
Fusarium Wilt ◽  
Dna Sequences ◽  
Vascular Tissue ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Spore Suspension ◽  
Vascular Bundles ◽  
Laboratory Manual ◽  
First Report ◽  
Blastn Analysis

In July 2010, fusarium wilt symptoms of tomato (Lycopersicon esculentum Mill.) plants were found in two commercial greenhouses in the Damyang area of Korea. Approximately 1% of 7,000 to 8,000 tomato plants were wilted and chlorotic in each greenhouse. The vascular tissue was usually dark brown and the discoloration extended to the apex. Fragments (each 5 × 5 mm) of the symptomatic tissue were surface-sterilized with 1% NaOCl for 1 min, then rinsed twice in sterilized distilled water (SDW). The tissue pieces were placed on water agar and incubated at 25°C for 4 to 6 days. Nine Fusarium isolates were obtained from four diseased plants, of which three isolates were identified as F. oxysporum based on morphological characteristics on carnation leaf agar medium and DNA sequences of the translation elongation factor 1-alpha (EF-1α) gene (2). Macroconidia were mostly 3- to 5-septate, slightly curved, and 28 to 53 × 2.8 to 5.2 μm. Microconidia were abundant, borne in false heads or short monophialides, generally single-celled, oval to kidney shaped, and 5 to 23 × 3 to 5 μm. Chlamydospores were single or in short chains. The EF-1α gene was amplified from three isolates by PCR assay using ef1 and ef2 primers (3), and the amplification products were sequenced. The nucleotide sequences obtained were deposited in GenBank (Accession Nos. KC491844, KC491845, and KC491846). BLASTn analysis showed 99% homology with the EF-1α sequence of F. oxysporum f. sp. lycopersici MN-24 (HM057331). Pathogenicity tests and race determination were conducted using root-dip inoculation (4) on seedlings of tomato differential cultivars: Ponderosa (susceptible to all races), Momotaro (resistant to race 1), Walter (resistant to races 1 and 2), and I3R-1 (resistant to all races). A spore suspension was prepared by flooding 5-day-old cultures on potato dextrose agar with SDW. Plants at the first true-leaf stage were inoculated by dipping the roots in the spore suspension (1 × 106 conidia/ml) for 10 min. Inoculated plants were transplanted into pots containing sterilized soil, and maintained in the greenhouse at 25/20°C (12/12 h). Twenty-four seedlings of each cultivar were arranged into three replications. An equal number of plants of each cultivar dipped in water were used as control treatments. Disease reaction was evaluated 3 weeks after inoculation, using a disease index on a scale of 0 to 4 (0 = no symptoms, 1 = slightly swollen and/or bent hypocotyl, 2 = one or two brown vascular bundles in the hypocotyl, 3 = at least two brown vascular bundles and growth distortion, 4 = all vascular bundles brown and the plant either dead or very small and wilted). All isolates caused symptoms of fusarium wilt on all cultivars except I3R-1, indicating that the isolates were race 3. The pathogen was reisolated from the discolored vascular tissue of symptomatic plants. Control plants remained asymptomatic, and the pathogen was not reisolated from the vascular tissue. Fusarium wilt of tomato caused by isolates of F. oxysporum f. sp. lycopersici races 1 and 2 has been reported previously; however, race 3 has not been reported in Korea (1). To our knowledge, this is the first report of isolates of F. oxysporum f. sp. lycopersici race 3 on tomato in Korea. References: (1) O. S. Hur et al. Res. Plant Dis. 18:304, 2012 (in Korean). (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) K. O'Donnell et al. Proc. Nat. Acad. Sci. 95:2044, 1998. (4) M. Rep et al. Mol. Microbiol. 53:1373, 2004.

scholarly journals New data on the oldest turtles: revision and reconsideration of Proterochersidae

2015 ◽  
Author(s):  
Tomasz Szczygielski
Keyword(s):  
Phylogenetic Tree ◽  
Crucial Role ◽  
Divergence Time ◽  
Strong Support ◽  
Crown Group ◽  
Stratigraphic Position ◽  
Competing Hypotheses ◽  
Split Time ◽  
Basal Position ◽  
Stem Position

Background. The origin of turtles, their earliest evolution and the homologies of the elements building their shell are still enigmatic and remain an object of ongoing discussion and research. Although the oldest fully shelled turtle – Proterochersis robusta from the Lower Stubensandstein (Norian) of Germany – was described more than a century ago, until recently it was mostly ignored by researchers. This is surprising, not only because of its notable stratigraphic position, but also due to the critical significance of this taxon in two competing hypotheses of turtle interrelationships. The divergence time of two main branches of Testudines crown group depends on whether Proterochersis is a basal pleurodire or a stem turtle. Methods. A detailed study of the German material of Proterochersis and Murrhardtia was performed by the author and the available specimens were compared with still growing collection of proterochersid remains from the Norian location in Poręba (Poland). Results. Two controversial taxa from Germany, Proterochersis intermedia and Murrhardtia staeschei are proved to be the synonyms of P. robusta. Establishment of another two proterochersid taxa is proposed and new primitive postcranial characters are recognized, supporting the stem position of Proterochersidae on the turtle phylogenetic tree. Discussion. Two general hypotheses concerning the split time of Cryptodira and Pleurodira are functioning in the literature, and Proterochersis plays a crucial role in these considerations. According to traditional view, this taxon is the oldest side-necked turtle, based on the sutural connection between its pelvis and shell. Numerous recent analyses tended to allocate the Pleurodira much higher on the tree, resulting in stem position of Proterochersis, though such placement usually lacked a strong support. This was caused by an incompletness of Proterochersis material (only shells) and errors in interpretation of some characters. New data, gathered mostly from the Polish – much more complete and well preserved – specimens, supports the basal position of Proterochersidae and provides new insights in the ancestral structure of the turtle shell.

scholarly journals Problems related to the taxonomic placement of incompletely preserved amber fossils: transfer of the Paleogene liverwort <i>Cylindrocolea dimorpha</i> (Cephaloziellaceae) to the extant <i>Odontoschisma</i> sect. <i>Iwatsukia</i> (Cephaloziaceae)

Fossil Record ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Kathrin Feldberg ◽  
Jiří Váňa ◽  
Alfons Schäfer-Verwimp ◽  
Michael Krings ◽  
Carsten Gröhn ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Sequence Data ◽  
Divergence Time ◽  
New Combination ◽  
Crown Group ◽  
Fossil Species ◽  
Dna Sequence Data ◽  
Divergence Time Estimates ◽  
Time Estimates ◽  
The Baltic

Abstract. A revision of the Baltic and Bitterfeld amber fossils assigned to Cylindrocolea dimorpha (Cephaloziellaceae) has yielded evidence of the presence of multicellular, bifid underleaves, which have not previously been reported for this species and conflict with the current circumscription of the family. We transfer the fossil species to Odontoschisma (sect. Iwatsukia) and propose the new combination O. dimorpha of the Cephaloziaceae. Characteristics of the fossil include an overall small size of the plant, entire-margined, bifid leaves and underleaves, more or less equally thickened leaf cell walls, ventral branching that includes stoloniform branches with reduced leaves, and the lack of a stem hyalodermis and gemmae. Placement of the fossil in Cephaloziaceae profoundly affects divergence time estimates for liverworts based on DNA sequence variation with integrated information from the fossil record. Our reclassification concurs with hypotheses on the divergence times of Cephaloziaceae derived from DNA sequence data that provide evidence of a late Early Cretaceous to early Eocene age of the Odontoschisma crown group and an origin of O. sect. Iwatsukia in the Late Cretaceous to Oligocene.

scholarly journals Anatomical and morphological features of seedlings of some Cactoideae Eaton (Cactaceae Juss.) species

2016 ◽  
Vol 69 (4) ◽  
Author(s):  
Halyna Kalashnyk ◽  
Nataliia Nuzhyna ◽  
Maryna Gaidarzhy
Keyword(s):  
Calcium Oxalate ◽  
Vascular Tissue ◽  
Morphological Structure ◽  
Morphological Features ◽  
Vascular Bundles ◽  
Sectional Area ◽  
Cross Sectional ◽  
Arid Conditions ◽  
Pith Parenchyma ◽  
Thin Walled

<p>Three-month-old seedlings of 11 species of the subfamily Cactoideae (<em>Melocactus bahiensis</em>, <em>Melocactus curvispinus</em>, <em>Echinopsis eyriesii</em>, <em>E. mirablis</em>, <em>E. peruviana</em>, <em>Oreocereus celsianus</em>, <em>Rebutia flavistyla</em>, <em>Rebutia minuscula</em>, <em>Astrophytum myriostigma</em>, <em>Mamillaria columbiana</em>, and <em>M. prolifera</em>) have been studied. These plants exhibit a uniseriate epidermis, covered by a thin cuticle. Except for <em>E. peruviana</em> and <em>A. myriostigma</em>, no hypodermis could be detected. The shoots of all studied specimens consist mainly of cortex parenchyma with large thin-walled cells. The pith parenchyma is composed of much smaller cells. Due to the fact that the cortex parenchyma comprises the largest portion of the cross-sectional area, it can be concluded that it is the main water-storing tissue. The extent of vascular tissue development varies. Collateral vascular bundles are present in the stele. The studied seedlings contain various ergastic substances, in particular inclusions of calcium oxalate (all studied species), starch (<em>Mammillaria prolifera</em>, <em>E. mirabilis</em>, and the genus <em>Melocactus</em>), inulin-like inclusions, and occasionally lipid drops (some <em>Echinopsis</em> species).</p><p>Thus, it was found that all studied plants have a highly specialized anatomical and morphological structure. At the same time, the epidermis and hypodermis are poorly developed. Accordingly, the adaptation to arid conditions of the examined seedlings involves an increased growth of the water-storing tissue and the production of ergastic substances.</p>

scholarly journals Functional Analysis of the Phosphate Transporter Gene MtPT6 From Medicago truncatula

2021 ◽  
Vol 11 ◽  
Author(s):  
Yuman Cao ◽  
Jinlong Liu ◽  
Yuanying Li ◽  
Jing Zhang ◽  
Shuxia Li ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Vascular Tissue ◽  
Phosphate Transporter ◽  
Vascular Bundles ◽  
Transporter Gene ◽  
Cortical Cells ◽  
Close Relationship ◽  
Localization Analysis ◽  
Global Agriculture ◽  
Almost All

Phosphorus is one of the essential macronutrients required by plant growth and development, but phosphate resources are finite and diminishing rapidly because of the huge need in global agriculture. In this study, 11 genes were found in the Phosphate Transporter 1 (PHT1) family of Medicago truncatula. Seven genes of the PHT1 family were available by qRT-PCR. Most of them were expressed in roots, and almost all genes were induced by low-phosphate stress in the nodule. The expression of MtPT6 was relatively high in nodules and induced by low-phosphate stress. The fusion expression of MtPT6 promoter-GUS gene in M. truncatula suggested that the expression of MtPT6 was induced in roots and nodules by phosphate starvation. In roots, MtPT6 was mainly expressed in vascular tissue and tips, and it was also expressed in cortex under low-phosphate stress; in nodules, it was mainly expressed in vascular bundles, cortical cells, and fixation zone cells. MtPT6 had a close relationship with other PHT1 family members according to amino acid alignment and phylogenetic analysis. Subcellular localization analysis in tobacco revealed that MtPT6 protein was localized to the plasma membrane. The heterologous expression of MtPT6 in Arabidopsis knockout mutants of pht1.1 and pht1.4 made seedlings more susceptible to arsenate treatment, and the phosphate concentrations in pht1.1 were higher in high phosphate condition by expressing MtPT6. We conclude that MtPT6 is a typical phosphate transporter gene and can promote phosphate acquisition efficiency of plants.

scholarly journals A Burmese amber fossil of <i>Radula</i> (Porellales, Jungermanniopsida) provides insights into the Cretaceous evolution of epiphytic lineages of leafy liverworts

Fossil Record ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 201-213 ◽  
Author(s):  
Julia Bechteler ◽  
Alexander R. Schmidt ◽  
Matthew A. M. Renner ◽  
Bo Wang ◽  
Oscar Alejandro Pérez-Escobar ◽  
...  
Keyword(s):  
Divergence Time ◽  
Character State ◽  
Posterior Density ◽  
Crown Group ◽  
Burmese Amber ◽  
Divergence Time Estimates ◽  
Time Estimates ◽  
Leafy Liverwort ◽  
Highest Posterior Density ◽  
Age Estimates

Abstract. DNA-based divergence time estimates suggested major changes in the composition of epiphyte lineages of liverworts during the Cretaceous; however, evidence from the fossil record is scarce. We present the first Cretaceous fossil of the predominantly epiphytic leafy liverwort genus Radula in ca. 100 Myr old Burmese amber. The fossil's exquisite preservation allows first insights into the morphology of early crown group representatives of Radula occurring in gymnosperm-dominated forests. Ancestral character state reconstruction aligns the fossil with the crown group of Radula subg. Odontoradula; however, corresponding divergence time estimates using the software BEAST lead to unrealistically old age estimates. Alternatively, assignment of the fossil to the stem of subg. Odontoradula results in a stem age estimate of Radula of 227.8 Ma (95 % highest posterior density (HPD): 165.7–306.7) and a crown group estimate of 176.3 Ma (135.1–227.4), in agreement with analyses employing standard substitution rates (stem age 235.6 Ma (142.9–368.5), crown group age 183.8 Ma (109.9–289.1)). The fossil likely belongs to the stem lineage of Radula subg. Odontoradula. The fossil's modern morphology suggests that switches from gymnosperm to angiosperm phorophytes occurred without changes in plant body plans in epiphytic liverworts. The fossil provides evidence for striking morphological homoplasy in time. Even conservative node assignments of the fossil support older rather than younger age estimates of the Radula crown group, involving origins for most extant subgenera by the end of the Cretaceous and diversification of their crown groups in the Cenozoic.

Sign in / Sign up

Export Citation Format

Share Document