Gametophytes of Ophioglossum engelmannii

1983 ◽  
Vol 61 (9) ◽  
pp. 2369-2373 ◽  
Author(s):  
Dean P. Whittier
Keyword(s):  
Nutrient Medium ◽  
Apical Cell ◽  
Axenic Culture ◽  
Inorganic Nutrients ◽  
Cylindrical Structures

Gametophytes of Ophioglossum engelmannii Prantl grow in axenic culture on a nutrient medium containing inorganic nutrients and sucrose. The dark-grown prothalli are long, white, cylindrical structures without rhizoids. The gametophyte has a meristem with a single apical cell. Antheridia, which are partially sunken, and archegonia, which have short necks, are interspersed along the gametophyte. The prothalli are endophyte free. Since the gametophytes of O. engelmannii are undescribed from nature, no comparisons can be made between gametophytes from culture and those from nature. However, gametophytes grown in axenic culture have a morphology which is normal for the genus.

The germination of Tmesipteris spores

1987 ◽  
Vol 65 (8) ◽  
pp. 1770-1772 ◽  
Author(s):  
Dean P. Whittier ◽  
David R. Given
Keyword(s):  
New Media ◽  
Nutrient Medium ◽  
Axenic Culture ◽  
Polar Axis ◽  
Mineral Elements

Spores of Tmesipteris elongata Dang, germinated in axenic culture on a nutrient medium containing mineral elements and 0.2% glucose after 8 months in the dark. No spores germinated in cultures kept in the light. Initiating germination, the monolete laesura (scar) split in the middle. As the laesura ruptured to its ends, the cell bulged out. The first division was perpendicular to the polar axis of the spore and formed distal and proximal cells. At one end of the proximal cell, brown materials accumulated in the wall. Transfer of the two-celled gametophyte to new media did not support further growth.

Germination of Psilotum spores in axenic culture

1973 ◽  
Vol 51 (10) ◽  
pp. 2000-2001 ◽  
Author(s):  
Dean P. Whittier
Keyword(s):  
Nutrient Medium ◽  
Axenic Culture ◽  
Mineral Elements ◽  
Psilotum Nudum

Spores of Psilotum nudum (L.) Griseb. germinated in axenic culture on a nutrient medium containing mineral elements and 0.25% sucrose after 6 months in the dark.

The effect of light and other factors on spore germination in Botrychium dissectum

1973 ◽  
Vol 51 (10) ◽  
pp. 1791-1794 ◽  
Author(s):  
Dean P. Whittier
Keyword(s):  
Spore Germination ◽  
Nutrient Medium ◽  
Axenic Culture ◽  
Effect Of Light

Light-inhibited spore germination in Botrychium dissectum forma obliquum occurred in axenic culture on a nutrient medium containing 0.25% sucrose. The spores had to be cultured in darkness for 3–4 weeks before any germination would take place. Longer periods in the dark produced greater percentages of germination. Sucrose was unnecessary for germination, but it promoted gametophytic growth once germination had occurred.

Induced apogamy in Tmesipteris (Psilotaceae)

2004 ◽  
Vol 82 (6) ◽  
pp. 721-725 ◽  
Author(s):  
Dean P Whittier
Keyword(s):  
Shoot Apical Meristem ◽  
Nutrient Medium ◽  
Apical Meristem ◽  
Vascular Tissue ◽  
Axenic Culture ◽  
Epidermal Cells ◽  
Direct Connection ◽  
Normal Anatomy ◽  
Induced Apogamy ◽  
Fern Gametophytes

Gametophytes of Tmesipteris lanceolata Dang., which are mycorrhizal in nature, were grown in axenic culture. If cultured in the light on a nutrient medium containing minerals and 0.5% glucose, they did not become photosynthetic; however, about 15% of them produced apogamous sporophytes with stems and microphylls. The gametophyte–sporophyte junction had a direct connection between the gametophyte and sporophyte tissues and lacked a foot, which is typical for apogamy. Gametangia were limited to the gametophyte portions of these gametophyte–sporophyte growths, and the vascular tissue was present only in the sporophyte regions. The apogamous aerial stems had the normal anatomy for a sporophyte, with vascular tissue, epidermal cells, stomata, and chlorenchyma. The origin of the apogamous sporophytes was different from the origin in fern gametophytes. The Tmesipteris sporophytes arose terminally from the gametophyte apices. It appears that the apical meristem of the gametophyte is converted to a shoot apical meristem to form the apogamous aerial shoot.Key words: Tmesipteris, Psilotaceae, apogamy, sporophyte, gametophyte.

Axenic culture of the downy mildew fungus Plasmopara halstedii in Agrobacterium rhizogenes-induced roots of sunflower (Helianthus annuus)

1991 ◽  
Vol 69 (12) ◽  
pp. 2709-2715 ◽  
Author(s):  
G. A. Zahka ◽  
F. Virányi
Keyword(s):  
Comparative Study ◽  
Helianthus Annuus ◽  
Downy Mildew ◽  
Agrobacterium Rhizogenes ◽  
Nutrient Medium ◽  
Axenic Culture ◽  
Root Culture ◽  
Good Source ◽  
Plasmopara Halstedii ◽  
Intact Plants

The downy mildew fungus, Plasmopara halstedii (Farlow) Berlese & de Toni, was cultured axenically in association with sunflower roots derived from petioles inoculated with Agrobacterium rhizogenes. An axenic zoosporangial suspension, obtained from sporulating cotyledons, was added to A. rhizogenes-induced root pieces on agar or in liquid nutrient medium. Roots showed profuse P. halstedii sporulation after 1 week. A comparative study in infection morphology with excised sunflower roots (not induced by A. rhizogenes) of the same cultivar showed no difference, both of which resembled P. halstedii infection in roots from intact plants. The dual-member cultures with A. rhizogenes induced roots were a good source of axenic P. halstedii inoculum, and zoosporangia remained viable for up to 2 monhts in dual-member cultures maintained at 18–20 °C. Noteworthy features were the balanced state of host and parasite and the prolific production of P. halstedii oospores. Key words: downy mildew, sunflower, Plasmopara halstedii, Helianthus annuus, root culture, Agrobacterium rhizogenes.

Development of a medium and culture system for in vitro propagation of the seagrass Halophila engelmannii

1994 ◽  
Vol 72 (10) ◽  
pp. 1503-1510 ◽  
Author(s):  
K. T. Bird ◽  
J. Jewett-Smith
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Culture System ◽  
Axenic Culture ◽  
Artificial Seawater ◽  
Inorganic Nutrients ◽  
Naphthaleneacetic Acid ◽  
N Source

An in vitro culture system was developed for axenic culture of the seagrass Halophila engelmannii Aschers. The culture system had a rhizome layer solidified with agar (0.8% w/v) and a liquid overlay layer. The rhizome layer contained artificial seawater (20%0, inorganic nutrients, plant growth regulators, sucrose (1% w/v), and activated charcoal (1% w/v). The overlay layer contained artificial seawater and inorganic nutrients. The medium f/4 provided the best source of inorganic nutrients of the five media compared. Axenic cultures of H. engelmannii died if NO3 was the only N source. They grew best when supplied with glutamic acid at a concentration of 3.4 mM as the N source. A combination of α-naphthaleneacetic acid at a concentration of 0.25 mg ∙ L−1 and 6-benzylaminopurine at a concentration of 10 mg ∙ L−1 provided the most rapid rates of propagation as measured by the numbers of pseudowhorls and branches produced. Key words: tissue culture, marine plants, media, plant growth regulators.

Gametophytes of Lycopodium obscurum as grown in axenic culture

1977 ◽  
Vol 55 (5) ◽  
pp. 563-567 ◽  
Author(s):  
Dean P. Whittier
Keyword(s):  
Endophytic Fungus ◽  
Axenic Culture ◽  
Thick Disk ◽  
Inorganic Nutrients

Gametophytes of Lycopodium obscurum were grown from spores in axenic culture on a medium containing inorganic nutrients and sucrose. The prothalli developed into thick, disk-shaped gametophytes which bore antheridia. No archegonia were observed on these 1-year-old gametophytes. The morphology of the prothalli in culture was essentially that described for prothalli of L. obscurum from nature. However, these Lycopodium gametophytes in culture developed without the endophytic fungus which is necessary for the growth of prothalli of L. obscurum in nature.

Cytoplasmic Organization in the Receptor Cells of the Crista Ampullaris

1972 ◽  
Vol 30 ◽  
pp. 60-61 ◽  
Author(s):  
Robert F. Dunn
Keyword(s):  
Fine Particles ◽  
Apical Cell ◽  
Apical Region ◽  
Receptor Cells ◽  
Cuticular Plate ◽  
Morphological Organization ◽  
Crista Ampullaris ◽  
Cytoplasmic Organization ◽  
High Degree ◽  
General Appearance

Receptor cells of the cristae in the vestibular labyrinth of the bullfrog, Rana catesbiana, show a high degree of morphological organization. Four specialized regions may be distinguished: the apical region, the supranuclear region, the paranuclear region, and the basilar region.The apical region includes a single kinocilium, approximately 40 stereocilia, and many small microvilli all projecting from the apical cell surface into the lumen of the ampulla. A cuticular plate, located at the base of the stereocilia, contains filamentous attachments of the stereocilia, and has the general appearance of a homogeneous aggregation of fine particles (Fig. 1). An accumulation of mitochondria is located within the cytoplasm basal to the cuticular plate.

Fine structure of the rectal papillae of the oriental fruuit fly, Dacus dorsalis Hendel (Tephritidae, Diptera Insecta)

1990 ◽  
Vol 48 (3) ◽  
pp. 498-499
Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin
Keyword(s):  
Fine Structure ◽  
Cell Membrane ◽  
Intercellular Space ◽  
Anterior Part ◽  
Apical Cell ◽  
Posterior Part ◽  
Apical Cell Membrane ◽  
Dacus Dorsalis ◽  
Radial Cell ◽  
Circular Base

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).

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