TELIOSPORE DEVELOPMENT IN THE PUCCINIASTREAE

1933 ◽  
Vol 9 (5) ◽  
pp. 458-485 ◽  
Author(s):  
S. M. Pady
Keyword(s):  
Epidermal Cells ◽  
The Other ◽  
General Situation ◽  
Thin Walled ◽  
Primordial Cell ◽  
Teliospore Development

The genera that constitute the Pucciniastreae display a wide variation in the type of teliospore produced, as well as in the time and place of production. From the standpoint of development, however, there is a general situation that is common. In all genera primordial cells are formed from enlarged hyphal cells of the mycelium. These give rise to teliospore initials which are in the epidermal cells in Calyptospora, Milesia, Hyalopsora and Thecopsora, and are subepidermal in the other genera. These initials divide to form the mature teliospores, which are thick or thin walled, and few to many-celled. In all cases the teliospore is the product of a single primordial cell.The teliospores of Calyptospora goeppertiana are formed from a perennial mycelium, which causes a witches' broom and hypertrophied stems on species of Vaccinium. The mycelium gives rise to primordial cells in the cortex just below the epidermis. Each primordial cell pierces the host wall above and the contents pass in to form the initial, which by growth and division becomes the teliospore. The mature teliospores are one- to four-celled, with a thickened, dark brown wall. Development is not simultaneous, but progressive, and the teliospores are first formed in the basal parts, moving slowly upward until every cell of the hypertrophied portion of the stem is completely filled. In four species of Milesia the method of development is similar. The spores, however, are thin walled, and are formed in the epidermal cells of the overwintered fronds of their fern hosts. Thecopsora vacciniorum is similar to Milesia in many respects. The teliospores are intra-epidermal, thin walled and multicellular. In Pucciniastrum the teliospores are subepidermal, and arise from primordial cells, as in Calyptospora, Milesia and Thecopsora. The teliospore initials are closely packed, and the mature spores may form extended crusts. The simplest type of development is found in Uredinopsis, which is generally considered to be the most primitive of the fern rusts. Primordial cells are formed in the same way as in the other genera. These round up to form the initials, and cross walls are laid down to give the mature spores.From these studies two possible lines of development are suggested, both beginning with Uredinopsis. One line would lead through the intra-epidermal forms, as Milesia, Calyptospora, etc., and the other through the subepidermal genera, as Pucciniastrum and Melampsoridium.

Pollen Presenter Morphology and Anatomy in Banksia and Dryandra

1996 ◽  
Vol 44 (4) ◽  
pp. 447 ◽  
Author(s):  
PG Ladd ◽  
AJ Alkema ◽  
GJ Thomson
Keyword(s):  
Lower Proportion ◽  
Epidermal Cells ◽  
The Other ◽  
Transmitting Tissue ◽  
Pollination Success ◽  
Cell Layers ◽  
Thin Walled

Style shape, and pollen presenter morphology and anatomy, are similar in Banksia L.f, and Dryandra R.Br. There are four style shapes-straight, bowed, s-shaped and hooked. However, in Dryandra, s-shaped and hooked styles are uncommon. The stigma in all cases is contained within the pollen presenter, but there is variation in the location of the stigmatic groove on the presenter, from truly apical (terminal), obliquely terminal to rarely located at the base of the presenter as in B. ericifolia. There is also variation in whether the pollen is deposited over the stigmatic groove in bud or the slit is free of pollen at anthesis. In Banksia, 73% of species studied have the groove covered with pollen, while in Dryandra, a somewhat lower proportion of species (50%) has this configuration. Pollen cohesion on the presenter varies from sticky to loose but is mostly slightly sticky. Similar pollen presenter forms occur in both genera, but in Dryandra, the generally less elaborate shapes are more frequent than is the case in Banksia. Anatomically, the pollen presenters are quite complex, with several cell layers concentrically disposed around the central transmitting tissue. There is considerable variation in the epidermal cells of the presenters between species. In most, the cells are small and thick-walled, but in B. ilicifolia, they are very thin-walled and enlarged into elongated projections. Similar forms occur in other species. In B. tricuspis, the epidermal cells are enlarged, regularly rounded in shape and become smaller and thick-walled near the stigmatic groove. Underlying the epidermis, polyphenol-containing cells and sclerenchyma vary in proportion between species and also in their location within the presenter. The variation in wall characteristics of epidermal cells and the proportion of sclerenchyma in different species is likely to be related to maximising pollination success within an environment containing a variety of pollinator behaviours. Although vertebrates are important in pollinating many species, invertebrates are likely to be the primary pollinators of a significant number of the other species in both genera.

Comparative leaf development of aerial and aquatic growth forms of Myriophyllum aquaticum

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Epidermal Cells ◽  
The Other ◽  
Developmental Study ◽  
Growth Forms ◽  
Myriophyllum Aquaticum ◽  
Stages Of Development ◽  
Qualitative And Quantitative ◽  
Early Stages ◽  
Other Hand

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.

scholarly journals The Figure of Distrust: Prince A.S. Menshikov in the Maritime Department during the Period of Reforms, 1826–1828

2020 ◽  
Vol 4 (3) ◽  
pp. 702-733
Author(s):  
Kseniya V. Donik
Keyword(s):  
Methodological Approach ◽  
The Other ◽  
General Situation ◽  
Functional Characteristics ◽  
Problem Context ◽  
Agent Based ◽  
The One ◽  
First Time ◽  
Official Records

The article considers the role of Prince A. Menshikov as a specific type of agent of supreme authority in the process of reforming the maritime administration. The problem context of reforms resulted from the involvement of the naval generals and officials in abuses, which was a consequence of nepotism and unrest in the navy. The involvement of sailors in the Decembrist revolt significantly affected the attitude of the tsar to the general situation in the naval environment. Distrustful of the existing naval administration, Nicholas I needed an intermediary who would implement his idea of the arrangement of the navy on the one hand, and provide him with an objective “impartial” account of maritime problems, on the other hand. As a result of that, Adjutant General Prince A. Menshikov, who had had nothing to do with the naval service earlier, joined the navy to become the monarch’s agent in charge of the naval issues in the bodies of autocratic authority. The objective of the article is to identify the functions of such an agent based on the example of the Maritime Department. The sources of the article include official records and personal documents, some of which are introduced into scientific circulation for the first time. The principal methodological approach to the problem under study is an attempt to bring the appointment of Menshikov beyond the scope of narrow departmental history which was based on the unmotivated decision of the emperor and to propose an interpretation of the events in the context of tsarist government via agents, which has already been described in historiography. The author makes a conclusion about the interconnection between the crisis in the naval department, the attitude of the supreme authority towards it, and the appearance of the monarch’s agent with a number of his own functional characteristics.

A new species and comparative morphology of Vesselowskya (Cunoniaceae)

2001 ◽  
Vol 14 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew C. Rozefelds ◽  
Richard W. Barnes ◽  
Belinda Pellow
Keyword(s):  
New Species ◽  
Cell Walls ◽  
New South ◽  
Comparative Morphology ◽  
Epidermal Cells ◽  
The Other ◽  
Abaxial Surface ◽  
South Wales ◽  
Central Column ◽  
A New Species

The vegetative and reproductive morphology of Vesselowskya Pampanini, southern marara, is described and illustrated in detail. The variation within V. rubifolia (F.Muell.) Pampanini sens. lat. is shown to be greater than has previously been recognised, with the differences identified supporting the recognition of a new segregate species, V. venusta Rozefelds, R.W.Barnes and Pellow sp. nov. Vesselowskya venusta occurs in the Barrington Tops Plateau of New South Wales and differs from V. rubifolia in possessing hairs on the abaxial surface of the sepals and lacking both a prominent distal connective protrusion on the anthers and colleters at the base of the stipules. The two Vesselowskya species are dioecious with a vestigial ovary in staminate flowers and reduced stamens in pistillate flowers. Dioecy is more pronounced in Vesselowskya, than in some Weinmannia species, and in both genera is expressed through reduction in the size of the ovaries in staminate flowers, and stamens in pistillate flowers. Vesselowskya shares with the other genera in the tribe Cunonieae (Pancheria, Weinmannia and Cunonia), a central column in the fruits, and Cunonia-type stipules, but differs from these genera in having valvate aestivation, digitate leaves, craspedodromous secondary venation with secondary veins terminating at a tooth, tuft domatia along the midrib, adaxial epidermal cells with strongly sinuous cell walls and the absence of hydathodes.

scholarly journals Sueria laxinervis, a new fossil species of Cycadales from the Upper Cretaceous Quiriquina Formation in Cocholgüe, Bíobío Region, Chile

Phytotaxa ◽  
2019 ◽  
Vol 402 (2) ◽  
pp. 126
Author(s):  
TOSHIHIRO YAMADA ◽  
TAKAE F. YAMADA ◽  
KAZUO TERADA ◽  
TAKESHI A. OHSAWA ◽  
ATSUSHI YABE ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Epidermal Cells ◽  
The Other ◽  
Vascular Bundles ◽  
Fossil Species

A new fossil cycad species, Sueria laxinervis, is described from the Upper Cretaceous (Maastrichtian) Quiriquina Formation in Cocholgüe, Bíobío Region, Chile. The generic assignment is supported by the taeniopterid-type leaf with haplocheilic stomata and sinuate anticlinal walls of leaf epidermal cells, while S. laxinervis clearly differs from the other two described Sueria species in its sparse veins and large epidermal cells. The vascular bundles of the midrib are arranged in an inverted-omega shape, supporting the placement of Sueria in Cycadales.

Floral anatomy of the Milla complex genera (Themidaceae)

2010 ◽  
Vol 87 ◽  
pp. 1
Author(s):  
Sofía Loza-Cornejo ◽  
Fernando Chiang Cabrera ◽  
Eduardo Ruiz-Sanchez ◽  
José Luis Villaseñor ◽  
Mario Ernesto Suárez-Mota ◽  
...  
Keyword(s):  
Floral Anatomy ◽  
Epidermal Cells ◽  
The Other ◽  
Floral Tube ◽  
Floral Buds ◽  
Parenchyma Cells ◽  
Anatomical Characters

Floral morpho-anatomy of the Milla complex genera (Themidaceae) was studied with the aim to confirm the occurrence of a gynophore in Dandya, to determine if there are anatomical characters that allow to distinguish Dandya from the rest of genera of the complex (Behria, Bessera, Jaimehintonia, Milla, and Petronymphe), and to understand their evolution. Floral buds of ten species of the Milla complex were studied through the standard paraffin microtechnique. The results demonstrated the presence of a gynophore without pith in Dandya, while the other genera have a gynophore with pith. In addition, Dandya differs from the other genera of the complex by a closed-stigma with external papillae, nectary cavities of horned-shape with tabular epidermal cells, and filaments with 4-strata of parenchyma cells. Behria and Bessera share characters such as connated stamens and an ovary with the external epidermis papillose. Attributes like gynophore with pith, percentage of adnnation between ovary and floral tube of 20-30%, stigma with an open ending, and nectary cavities with discoidal shape are probably ancestral conditions in the Milla complex, from which transformation of character states occurred mostly in Dandya.

Development of helicoidal texture in the prerelease mucilage of quince (Cydonia oblonga) seed epidermis

1988 ◽  
Vol 66 (3) ◽  
pp. 460-467 ◽  
Author(s):  
R. M. Abeysekera ◽  
J. H. M. Willison
Keyword(s):  
Central Region ◽  
Liquid Crystalline ◽  
Amorphous Material ◽  
Epidermal Cells ◽  
Cydonia Oblonga ◽  
Thin Walled ◽  
Seed Epidermis ◽  
Developmental Phases ◽  
Transitional Phase ◽  
Helicoidal Texture

Quince (Cydonia oblonga Mill.) seed epidermis was examined cytologically during its development. Three developmental phases were delimited: immaturity, transition to maturity, and maturity. These cytological phases corresponded with phases of competence to release hydrated mucilage on wetting, immature tissue being completely incompetent and mature tissue fully competent. Growing cells of immature tissue were vacuolate and thin walled. By contrast, protoplasts of nongrowing mature epidermal cells had contracted to a remnant and been replaced by periplasmic deposits. Within these deposits, surrounded by amorphous material, were massive arrays of widely spaced microfibrils arranged helicoidally. In the oldest sample examined, periplasmic material appeared to be spewing through the broken outer walls of some cells. The periplasmic material is interpreted to be prerelease mucilage, which progressively fills the periplasm during a brief transitional phase. It seems that amorphous periplasmic material is deposited initially and microfibrils later intermingle with it. At some stage during filling of the periplasm, the microfibrils begin to organize, ultimately becoming helicoidal. Orderliness seems to begin in the central region of the periplasmic pool, not at its edges. It is proposed that nucleation of liquid crystalline helicoidal arrays occurs in the periplasm and that these arrays remain fluid until their disintegration during release as a result of hydration.

Study on Zostera marina L. Seed Germination Ecological Characteristics in Variable Environmental

2013 ◽  
Vol 312 ◽  
pp. 866-870
Author(s):  
Yong Zheng Tang ◽  
Bao Chen Du ◽  
Hui Zhou
Keyword(s):  
Tissue Culture ◽  
Cell Wall ◽  
Zostera Marina ◽  
Male Flower ◽  
Epidermal Cells ◽  
The Other ◽  
Morphological Observation ◽  
Main Site ◽  
Monoecious Plant ◽  
Toxic Ions

The paper is mainly concerned with two parts in morphological observation and tissue culture of Eelgrass (Zostera marina L.).The results areas follows: 1.The microstructure of the plant showed that the cell wall exposing to seawater in epidermal cells of leaves was highly thickened, but the other sides were normal. It was also highly thickened in the side exposing to seawater in the epidermal cells of roots and stems. This structure may function as a barrier against toxic ions to enter the epidermal cells. Chloroplasts were found mainly in the epidermal cells, indicating that epidermal cells were main site where photosynthesis occurred. Aerenchyma was found everywhere in the plant which showed the ability of adaptation to submerged life. Anatomical observation of the inflorescence showed that eelgrass was a monoecious plant; the male flower and carpel were alternating arrangement on the inflorescence. SEM photographs of the stamen and the carpel indicated that the carpel had two stigmas; the pollens of the eelgrass were filamentous. All of the above observation showed that eelgrass is able to adapt to submerged life. The explants were dipped in 75%Alcohol for 10 seconds firstly, they were dipped in 1%NaClO 10 minutes, and this was the best way of sterilization than other treatments.

Anthocyanin Carrying Structures in Specific Genotypes of Matthiola incana R. Br.

1981 ◽  
Vol 36 (11-12) ◽  
pp. 925-927 ◽  
Author(s):  
V. Hemleben
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Epidermal Cells ◽  
The Other ◽  
Genetic Constitution ◽  
Anthocyanin Pigment ◽  
Matthiola Incana

Abstract Several lines of the genetically well defined Matthiola incana (Brassicaceae) concerning the anthocyanin biosynthesis (line 02, 06, 10, and 14) store the anthocyanin pigment as crystals (line 06) or in anthocyanoblasts (“balls”) in the epidermal cells (line 02, 10, and 14) of the flower petals. The genetic constitution of these genotypes is in addition to the basic factors f+, g+, and e+, b+b+ or bb (cyanidin or pelargonidin type), ll, u+u+, and v+v+ or vv, demonstrating that the ll, u+u+ constitution is responsible for precipitation of anthocyanins in a certain structure indepen­ dent of the other modificationally acting genes b and v. The ll, u+u+ types accumulate preferentially acylated 3-biosides.

Introduction to Asymptotic Theory: Volatility Estimation for a Continuous Process

2014 ◽  
Author(s):  
Yacine Aïıt-Sahalia ◽  
Jean Jacod
Keyword(s):  
Probability Theory ◽  
Central Limit ◽  
Limit Theorems ◽  
Continuous Process ◽  
The Other ◽  
General Situation ◽  
Simple Situation ◽  
One Dimensional ◽  
Integrated Volatility ◽  
Classical Probability Theory

This chapter presents the simple situation of a one-dimensional continuous martingale to “estimate” its integrated volatility. For pedagogical reasons, it demonstrates nearly every statement beyond classical probability theory, without appealing to outside results: “demonstrate” is in fact too ambitious a word, since complete proofs are quite intricate in the most general situation, but a precise scheme is given for all proofs, emphasizing methods and ideas. These schematic proofs can serve as a template for the other situations encountered in the book, whose proofs will typically invoke general central limit theorems that are only stated in Appendix A, or elsewhere in the literature.

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