Germination of Psilotum spores in axenic culture

1973 ◽  
Vol 51 (10) ◽  
pp. 2000-2001 ◽  
Author(s):  
Dean P. Whittier

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.

1987 ◽  
Vol 65 (8) ◽  
pp. 1770-1772 ◽  
Author(s):  
Dean P. Whittier ◽  
David R. Given

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.


1969 ◽  
Vol 47 (5) ◽  
pp. 773-777
Author(s):  
L. L. Treanor ◽  
D. P. Whittier

The effect of mineral nutrition on apogamy was studied because earlier investigators proposed that low mineral levels induced apogamy. The weight of the gametophytic tissue and the number of apogamous plants per culture and per gram of gametophytic tissue were determined in relation to variations in the levels of mineral elements. The apogamous response was promoted only by high concentrations of phosphorus, and an increase in the gametophytic weight was produced by high levels of potassium. The omission of any of the elements from the nutrient medium inhibited apogamy and, except calcium, reduced the gametophytic weight.


1983 ◽  
Vol 61 (9) ◽  
pp. 2369-2373 ◽  
Author(s):  
Dean P. Whittier

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.


1973 ◽  
Vol 51 (10) ◽  
pp. 1791-1794 ◽  
Author(s):  
Dean P. Whittier

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.


2004 ◽  
Vol 82 (6) ◽  
pp. 721-725 ◽  
Author(s):  
Dean P Whittier

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.


2013 ◽  
Vol 41 (2) ◽  
pp. 295-314
Author(s):  
Urszula Kruszelnicka

In the years 1977 - 1980, studies were conducted on the effect of sodium used to supplement low (K = 800 mg/5 kg) and high (K = 1400 mg/5 kg) potassium doses on the content of mineral components, their accumulation in the yield and the percentage of their utilization. The study was carried out on root celery - <i>Apium graveolens</i> L. var. <i>rapaceum</i> (Mill.) and stalk celery - <i>Apium graveolens</i> L. var. <i>dulce</i> (Mill.). The results obtained in these experiments point to the following conclusions: it was found that potassium and sodium mutually limit each other's uptake. Sodium was more antagonistic towards the uptake of calcium than was potassium. However, no clearly antagonistic effect of these elements on the uptake of magnesium was determined. The accumulation of potassium and sodium by the experimental plants rose while the percentage of utilization of these elements decreased as their level in the nutrient medium increased. Sodium exerted a more distinct effect on the accumulation and utilization of other mineral elements than did potassium.


1991 ◽  
Vol 69 (12) ◽  
pp. 2709-2715 ◽  
Author(s):  
G. A. Zahka ◽  
F. Virányi

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.


Author(s):  
P. Dayanandan ◽  
P. B. Kaufman

A three dimensional appreciation of the guard cell morphology coupled with ultrastjuctural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.


Author(s):  
A. K. Veligodska ◽  
O. V. Fedotov ◽  
A. S. Petreeva

<p>The influence of certain nitrogen compounds - components of glucose-peptone medium (GPM) on the accumulation of carotenoids by some strains was investigated by surface cultivating basidiomycetes. The total carotenoid content was set in acetone extracts of mycological material spectrophotometrically and calculated using the Vetshteyn formula.</p> <p>As the nitrogen-containing components used GPM with 9 compounds, such as peptone, DL-valine, L-asparagine, DL-serine, DL-tyrosine, L-proline, L-alanine, urea, NaNO<sub>3</sub>. The effect on the accumulation of specific compounds both in the mycelium and in the culture fluid of carotenoids by culturing certain strains of Basidiomycetes was identified.</p> <p>Adding to standard glucose-peptone medium peptone at 5 g/l causes an increase of carotenoid accumulation by strain <em>L. sulphureus</em> Ls-08, and in a concentration of 4 g/l by strains of <em>F. hepatica </em>Fh-18 and <em>F. fomentarius</em> Ff-1201.</p> <p>In order to increase the accumulation of carotenoids in the mycelium  we suggested to make a standard glucose-peptone medium with proline or valine for cultivating of <em>L. sulphureus</em> Ls- 08 strain; alanine for <em>F. fomentarius</em> Ff-1201 strain; proline, asparagine and serine - for strain Fh-18 of <em>F. hepatica</em>. The results can be implemented in further optimization of the composition of the nutrient medium for culturing strains of Basidiomycetes wich producing carotenoids.</p> <p><em>Keywords: nitrogen-containing substances, Basidiomycetes, mycelium</em><em>,</em><em> culture filtrate, carotenoids</em></p>


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