Comparative embryology of Stipa elmeri (Gramineae)

1973 ◽  
Vol 51 (1) ◽  
pp. 235-247 ◽  
Author(s):  
Jack Maze ◽  
Lesley R. Bohm
Keyword(s):  
Pollen Tube ◽  
Outer Layer ◽  
Growth Pattern ◽  
Outer Integument ◽  
Stages Of Development ◽  
Cytological Change ◽  
Close Relationship ◽  
Fruit Wall ◽  
Comparative Embryology ◽  
Number Of Cells

The ovule of Stipa elmeri is bitegmetic, hemianatropous, and pseudocrassinucellate. The micropyle is formed by the inner integument. The inner integument is two cells thick except at the micropyle. Its inner layer is persistent and safraninophilic, and some of its cells develop secondary walls. A cuticle is also present outside the inner integument. The outer integument is two cells thick except for a bump four or five cells thick at the chalazal end. At later stages of development, the outer integument breaks down except at the chalazal end. As the ovule develops, it undergoes changes in orientation as a result of growth pattern changes in the nucellus. A multiple protoderm is present in some parts of the nucellus.The outer layer of the nucellus persists to later stages of development and is covered by a cuticle. Fruit wall changes during development are (1) formation of a thick, unlignified wall on the protoderm, (2) elongation of cells lining the locule, and (3) decrease in number of cells. Megagametophyte development is normal and the antipodals proliferate. Before fertilization, both synergids undergo cytological change and one decreases in size. The pollen tube appears to enter at the base of the larger synergid. The endosperm is free nuclear at first but then becomes cellular. At later stages of development, the outer layer of the endosperm is meristematic. On the basis of embryological data, the following phenetic series can be constructed: S. elmeri → S. lemmonii – S. hendersonii → S. tortilis → Oryzopsis miliacea. Available embryological data does not indicate a close relationship between the Gramineae and the Juncaceae or Cyperaceae.

Embryology of Agrostis interrupta (Gramineae)

1974 ◽  
Vol 52 (2) ◽  
pp. 365-379 ◽  
Author(s):  
Jack Maze ◽  
Lesley R. Bohm
Keyword(s):  
Pollen Tube ◽  
Developmental Stages ◽  
Outer Integument ◽  
Rare Occurrence ◽  
Taxonomic Significance ◽  
Filiform Apparatus ◽  
Hormonal Imbalance ◽  
Cytological Abnormalities ◽  
Fruit Wall ◽  
Similarities And Differences

Because of the characteristic morphology of the grass ovule, it is proposed that the end of the ovule opposite the micropyle be referred to as the basal end rather than the chalazal end. The ovule is hemianatropous, bitegmetic, and tenuinucellate. Both integuments are mostly two cells thick and exhibit some stretching of individual cells along the side of the ovule. This stretching is concomitant with increase in ovule length. The inner integument forms the micropyle and persists longer than the outer integument. Elimination of the outer integument is a result of stretching. The fruit wall is unlignified as a result of the transfer of the function of protection to the lemma. As evidenced by patterns of cell elongation, fruit elongation occurs first along the sides. There are few periclinal divisions in the nucellar protoderm, these occurring near the point of attachment of the ovule. Megasporogenesis and megagametogenesis are normal. Callose is associated with megaspore formation. The mature orientation of the megagametophyte, relative to the placenta, is obtained at approximately the two-nucleate state of development. Antipodal proliferation occurs before fertilization. After fertilization, large multinucleolate nuclei and multinucleate cells are seen in the antipodals. The cytological abnormalities seen in the antipodals may be associated with hormonal imbalance. The synergid, which will be penetrated by the pollen tube, develops a filiform apparatus before the other synergid. The pollen tube deposits sperm cells in a degenerated synergid. Endosperm is free nuclear and walls form first around the embryo. Starch appears at later developmental stages in the endosperm. When cellular, the endosperm grows by cell division at its periphery. There are two morphological axes within the grass ovule, that between the egg apparatus and the antipodals and that between the micropyle and basal end. In Agrostis interrupta, these two axes form a wide angle. Embryologically, A. interrupta is more similar to Avena. There are also embryological features that seem to characterize the Aveneae and Stipeae. Three general types of embryological similarities and differences can be discerned in the grasses, as well as in other plants: (1) similarities and differences that reflect relationships; (2) similarities of rare occurrence with no obvious taxonomic significance; (3) rare differences of no obvious taxonomic significance.

Pollen-tube growth pattern and chalazogamy in Casuarina equisetifolia (Casuarinaceae)

2004 ◽  
Vol 117 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Akiko Sogo ◽  
Junko Noguchi ◽  
Tanguy Jaffr� ◽  
Hiroshi Tobe
Keyword(s):  
Pollen Tube ◽  
Growth Pattern ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Casuarina Equisetifolia

scholarly journals Development and morphology of the fruit and seed of the hemiparasite genus Jodina (Cervantesiaceae)

2017 ◽  
Vol 74 (1) ◽  
pp. 051
Author(s):  
María Luján Luna ◽  
Gabriela E. Giudice ◽  
Mariana A. Grossi ◽  
Diego G. Gutiérrez
Keyword(s):  
South America ◽  
Seed Development ◽  
Monotypic Genus ◽  
Stages Of Development ◽  
Fruit Type ◽  
Fruit Wall ◽  
Sem Studies

The monotypic genus Jodina is endemic to central and southeastern South America, common in forests and scrubland environments. The fruit type in Jodina is controversial since it has been described at different stages of development. The main objective of this work was to analyze the morphology of the fruit of J. rhombifolia during its maturation to attain a consensus about its type. Also characteristics of seed development and anatomy were analyzed in detail. Material was processed according to conventional techniques for LM and SEM studies. The fruit of J. rhombifolia is a pseudodrupe since the ovary is half-inferior; the fleshy layer of the pericarp is constituted by an increase of the nectary disk whereas the stony layer is represented by the mesocarp. Participation of the nectary disk as part of the fruit wall has not been mentioned previously. The seed is “naked” —the integument disintegrates during development— and the resulting structure is a pyrene. The interpretations made by other authors on the fruit of Jodina are also discussed.

Embryo sac and early ovule development in Oryzopsis miliacea and Stipa tortilis

1970 ◽  
Vol 48 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Jack Maze ◽  
Lesly R. Bohm ◽  
Lyle E. Mehlenbacher Jr.
Keyword(s):  
Cell Division ◽  
Pollen Tube ◽  
Nuclear Division ◽  
Outer Integument ◽  
Embryo Sac ◽  
Ovule Development ◽  
Polygonum Type ◽  
Embryo Sac Development

The ovules of Stipa tortilis and Oryzopsis miliacea are hemianatropous, bitegmetic, and pseudocrassinucellate (sensu Davis 1966). The hemianatropous shape of the ovule is the result of characteristic patterns of cell division and enlargement in the chalazal area and areas alongside the embryo sac. Embryo sac development in both is Polygonum-type and both have proliferating antipodals. Endosperm is nuclear, although in O. miliacea it is atypical in that nuclear division is synchronous within one portion of the embryo sac, e.g. micropylar, but not synchronous between different portions of the embryo sac, e.g., micropylar and chalazal. Differences in ovule initiation, persistence of the outer integument, fate of the inner integument, nature of the nucellus, shape of the embryo sac, nature of the synergids, cytoplasm of the egg, polar nuclei, and endosperm exist between these two taxa. Both synergids of O. miliacea undergo changes before fertilization and one degenerates before fertilization. The pollen tube enters the embryo sac at the base of the persistent synergid. There is presently insufficient embryological data to permit meaningful speculation on relationships between Stipa and Oryzopsis. Embryologically, Stipa and Oryzopsis are festucoid grasses, as much other evidence indicates. Embryo sac development in the Gramineae is more similar to that of the Restionaceae than to that of the Cyperaceae. This is in contradiction to recent speculations on the relationships of the Gramineae.

Ultrastructure of the cuticular membranes of the developing wheat grain

1975 ◽  
Vol 53 (18) ◽  
pp. 2077-2087 ◽  
Author(s):  
I. N. Morrison
Keyword(s):  
Triticum Aestivum ◽  
Outer Layer ◽  
Outer Integument ◽  
Triticum Aestivum L ◽  
Ultrastructural Level ◽  
Ultrastructural Changes ◽  
Grain Development ◽  
Wheat Grain ◽  
Maximum Thickness ◽  
Days After Anthesis

The distribution of cuticular membranes within the mature wheat ovule (Triticum aestivum L. cv. Heron) and the subsequent changes in these layers during grain development were investigated at the ultrastructural level. At anthesis, the inner epidermis of the pericarp and the outer integument are separated by two, thin, osmiophilic, cuticle-like lamellae. Similar osmiophilic boundaries, also double in nature, are evident between the outer and inner integuments and between the inner integument and the nucellar epidermis. By 7 days after anthesis, only the outer layer of cells of the inner integument and the nucellar epidermis are bounded by cuticularized layers, which, by this time, are recognizable as the developing outer and inner cuticles, respectively, of the mature caryopsis. Between 7 and 14 days after anthesis, the outer cuticle assumes a highly reticulate appearance in section and is delineated on the outside by a cutin layer, 90–120 nm in thickness. By 17 days both the outer and inner cuticles have attained maximum thickness, varying from 3.0 to 3.6 μm and 0.8 to 1.1 μm, respectively. Unlike the outer cuticle, the inner cuticle has no distinct internal substructure. The two are closely appressed by 4 weeks after anthesis and show no further ultrastructural changes.

scholarly journals Climatic and physiological regulation of the bimodal xylem formation pattern in Pinus pinaster saplings

2019 ◽  
Vol 39 (12) ◽  
pp. 2008-2018 ◽  
Author(s):  
Núria Garcia-Forner ◽  
Joana Vieira ◽  
Cristina Nabais ◽  
Ana Carvalho ◽  
Jordi Martínez-Vilalta ◽  
...  
Keyword(s):  
Water Availability ◽  
Growth Pattern ◽  
Pinus Pinaster ◽  
Cambial Activity ◽  
Fine Tuning ◽  
Wall Thickening ◽  
Physiological Variables ◽  
Second Growth ◽  
Xylem Formation ◽  
Number Of Cells

Abstract Seasonality in tree cambial activity and xylem formation encompass large variation in environmental conditions. Abiotic stressors such as warming or drought also modulate plant behavior at species and individual level. Despite xylem formation susceptibility to carbon (C) and water availability, it is still unknown which are the key physiological variables that regulate xylogenesis, and to what extent plant performance contributes to further explain the number of cells in the different phases of xylem development. Xylogenesis and physiological behavior was monitored in saplings of Pinus pinaster Aiton, a bimodal growth pattern species, distributed in different irrigation regimes. Xylogenesis and plant physiological behavior were compared between treatments and the relationship between climate, physiology and the number of cells in the cambium, enlargement and cell-wall thickening phases was evaluated. Xylogenesis regulation shifted from physiological to climatic control as cell differentiation advanced to mature tracheids. The number of cells in the cambium increased with assimilation rates and decreased with the water potential gradient through the plant. Enlargement was the most susceptible phase to plant relative water content, whereas no physiological variable contributed to explain the number of cells in the wall thickening phase, which declined as temperatures increased. All treatments showed a bimodal growth pattern with a second growth period starting when primary growth was completed and after plants had experienced the highest summer hydraulic losses. Our study demonstrates the importance of including physiological responses and not only climate to fully understand xylogenesis, with special attention to the enlargement phase. This is critical when studying species with a bimodal growth pattern because the second growth peak responds to internal shifts of C allocation and may strongly depend on plant hydraulic responses and not on a fine tuning of cambial activity with soil water availability.

Embryology of Brassica campestris: the entrance and discharge of the pollen tube in the synergid and the formation of the zygote

1992 ◽  
Vol 70 (8) ◽  
pp. 1577-1590 ◽  
Author(s):  
M. J. Sumner
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Pollen Tube ◽  
Brassica Campestris ◽  
Periodic Acid ◽  
Outer Integument ◽  
Central Cell ◽  
Egg Cell ◽  
Intense Staining

The postanthesis synergids and zygote of Brassica campestris cv. Candle were examined using techniques of light, fluorescence, and electron microscopy. The pollen tube enters the degenerate synergid by way of the filiform apparatus. A degeneration of one of the two synergids occurs after anthesis and is independent of pollination. The first sign of synergid degeneration is a more intense staining of one of the synergids, followed by a loss of organelle membrane integrity. There is a disappearance of the plasma membrane and dictyosome cisternae; however, profiles of degenerate synergid mitochondria, plastids, and dilated endoplasmic reticulum remain along with dictyosome vesicles that contain periodic acid – thiocarbo-hydrazide – silver proteinate positive substances. The zygote, shortly after fertilization, is reduced in size and lacks the large micropylar vacuole characteristic of the mature unfertilized egg cell. Plastids and mitochondria are concentrated around the centrally located nucleus of the zygote, and dictyosomes, active in vesicle production, are located in the lateral and chalazal regions of the cell, adjacent to the cell wall. The lateral cell walls are periodic acid – Schiff's and Calcofluor positive, while the ampulliform chalazal tip of the cell is weakly periodic acid – Schiff s positive and Calcofluor negative. Microtubules, with the long axis perpendicular to the long axis of the zygote, are abundant in the ampulliform chalazal tip of the cell. Following fertilization the central cell becomes highly vacuolate. There is continuity between the zygote – central cell plasma membrane, the central cell vacuole tonoplast, and membranes of the central cell endoplasmic reticulum. Central cell wall projections, of the transfer cell type, are located in the lateral regions of the megagametophyte adjacent to the developing zygote cell and are positioned adjacent to the region of inner and outer integument starch. Key words: Brassica, ultrastructure, synergid, megagametophyte, pollen tube, zygote.

scholarly journals HUBUNGAN PANJANG DAN BERAT IKAN NILA (Oreochromis niloticus) DALAM MEDIA PEMBESARAN DENGAN PENAMBAHAN ENZIM EZ-PLUS(SKALA LABORATORIUM)

2018 ◽  
Vol 7 (1) ◽  
pp. 150-156
Author(s):  
Muhammad Dwi Hudoyo Swarto ◽  
Haeruddin Haeruddin ◽  
Siti Rudiyanti
Keyword(s):  
Water Quality ◽  
Growth Pattern ◽  
Oreochromis Niloticus ◽  
Linear Regression Analysis ◽  
Measurement Data ◽  
Quality Measurement ◽  
Fish Feed ◽  
Weight Growth ◽  
Randomized Design ◽  
Close Relationship

Salah satu upaya untuk mengoptimalkan pertumbuhan panjang dan berat dalam kegiatan pembesaran ikan Nila adalah memperbaiki daya cerna dengan cara pemberian enzim EZ-plus ke dalam pakan ikan. Penelitian ini bertujuan untuk mengetahui pertumbuhan panjang dan bobot ikan Nila (Oreochromis niloticus) pada berbagai konsentrasi enzim yang ditambahkan pada pakan, serta keeratan hubungan antara pakan yang telah diberi enzim dengan pertambahan panjang total dan bobot ikan. Penelitian ini dilaksanakan selama 35 hari yaitu pada bulan Mei-Juni 2017. Metode dalam penelitian ini menggunakan eksperimental dengan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan sebagai berikut: kontrol, L (0,0125%), M (0,025%), N (0,05%) dan O (0,075%). Pemberian pakan dilakukan pada pagi hari dan sore hari dengan jumlah pakan yang diberikan 5% dari bobot ikan dalam sekali pemberian pakan.Selama penelitian dilakukan pergantian air setiap 7 hari untuk menjaga kualitas air. Data panjang dan bobot ikan dianalisis menggunakan regresi dan dilakukan uji F. Hasil penelitian pertumbuhan panjang berat diperoleh nilai b berkisar 2,43 – 3,09. Pola pertumbuhan pada perlakuan K, L, N, dan O yaitu alometrik negatif, sedangkan pola pertumbuhanpada perlakuan M yaitu isometrik. Hasil penelitian panjang berat diperoleh nilai R berkisar antara 0,86 – 0,96 atau mendekati nilai 1, menunjukkan adanya hubungan yang erat antara panjang dan berat ikan Nila. Data pengukuran kualitas air selama penelitian diperoleh temperatur berkisar antara 25,0 – 26,9 oC, pH berkisar antara 5,00 - 6,95 dan oksigen terlarut berkisar antara 4,01 – 6,89 mg/L. One of the effort to optimize the growth of length and weight in the activity oF Tilapia growout is to improve the digestibility by giving EZ-plus enzyme into fish feed. This research aims to determine the relationship between length and weight of Oreochromis niloticus growth in various concentrations of enzymes the feed, and closeness between feeds that have been given enzymes with length and weight growth of fish. This research was conducted for 35 days in May-June 2017. The experiment conducted with Complete Randomized Design with 5 treatments as follows: control, L (0,0125%), M (0,025%), N (0,05 %) and O (0,075%). Feeding done in the morning and afternoon with the amount 5% of fish weight in one feeding. During the research carried out water changes every 7 days to maintain water quality. The length – weight data were determined by linear regression analysis and F test. Result of research of length and weight growth obtained value of b ranged from 2,43 – 3,09. The growth pattern on the treatments of K, L, N and O are allometrik negative, while the growth pattern in  M treatment is isometric. Result of research length – weight growth obtained value of R ranged from 0,86 – 0,96 or close value 1, meaning a close relationship between the length – weight of Tilapia fish.. Water quality measurement data during the research obtained temperatures ranged from 25,0 – 26,9oC, the pH ranged from 5,00 to 6,95 and dissolved oxygen ranged from 4,01 to 6,89 mg / L.

Interspecific and Intergeneric Pistil - Pollen Compatibility of Banksia coccinea (Proteaceae)

1998 ◽  
Vol 46 (4) ◽  
pp. 453 ◽  
Author(s):  
T. L. Maguire ◽  
M. Sedgley
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Related Genus ◽  
Reciprocal Effect ◽  
Pollination Success ◽  
Intergeneric Crosses ◽  
Close Relationship ◽  
Species Groups ◽  
The Relationship

Interspecific and intergeneric pollen-tube growth was investigated using controlled hand pollinations of Banksia coccinea R.Br., 35 species of Banksia L.f., and three species of the related genus Dryandra R.Br. Currently, the relationship between B. coccinea and other species groups within Banksia is unclear. Some species supported no germination of B. coccinea pollen, some supported normal pollen-tube growth and others produced pollen-tube abnormalities including thickened walls, bulbous swellings, directionless growth, burst tips and branched tubes. Control of pollen-tube growth in the pistil was imposed in the pollen presenter and upper style. There was no significant reciprocal effect on pollination success in the lower style. The results of pollen-tube compatability in the lower style indicated that B. coccinea has a closer affinity to the section Oncostylis, than the section Banksia where it is currently placed. Intergeneric crosses of B. coccinea with Dryandra species resulted in some compatibility, with one cross having low numbers of pollen-tubes in the pollen presenter and upper style region. These results indicate a close relationship between Banksia and Dryandra, which are sister genera in the tribe Banksiae, family Proteaceae.

Fruit and seed development in mung beans (Phaseolus aureus Roxb.)

1978 ◽  
Vol 90 (3) ◽  
pp. 551-556 ◽  
Author(s):  
K. S. Savithri ◽  
P. S. Ganapathy ◽  
S. K. Sinha
Keyword(s):  
Quantitative Study ◽  
Dry Matter ◽  
Fruit Set ◽  
Functional Unit ◽  
Phaseolus Aureus ◽  
Stages Of Development ◽  
Developing Seeds ◽  
Plant Parts ◽  
Fruit Wall ◽  
Made In

SummaryA study of fruit set at different nodes was made in mung beans, Phaseolus aureus Roxb., under field conditions. Flowering commenced on the fourth node from the base and the percentage fruit set showed a gradual decrease from the fifth node upwards. Yield analysis was carried out for each of the fruiting nodes. When the leaf and inflorescences at a node are taken as a functional unit it is seen that there was a decrease in the ratio of leaf area to fruit and seed weights from the base of the plant upwards indicating that at the upper nodes particularly, some other plant parts also contribute to the photosynthate pool of the developing seeds.A quantitative study of the dry matter, proteins and starch in the fruit wall and seeds of fruits at different stages of development was made. It showed that the rapid increase in dry matter, proteins and starch in the seeds at the later stages of development is compensated, in part, by a decrease of these components in the fruit wall. Histochemical studies of the fruit wall further supported these observations. This indicated the contribution of substrates by the fruit wall to the developing seeds.

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