Life Sciences Commons^™

The Pollen Exostructure Of Striga (Scrophulariaceae), Mark A. Deleonardis

Biological Sciences Theses & Dissertations

In this survey, the pollen exostructure of 13 Striga species was examined using light microscopy and scanning electron microscopy. Two of the 13 species were also observed by transmission electron microscopy to assess major differences in exine composition. Striga pollen is consistently spherical to oblate, isopolar, tectate, and three or four colpate. Sculpturing may be psilate, psilate-perforate, finely rugulate, or coarsely rugulate. The equatorial width of the species surveyed ranged from 15 to 30 micrometers. It is concluded that variation in Striga pollen sculpturing, aperture structure, and size support the current taxonomy of the genus.

The Effect Of Pre-Sterile Medium Ph Photoperiod And N6-(2-Isopentenyl)-Adenine (2ip) On Shoot Production During Stage Ii Micropropagation Of Rhododendrons, Lori Longo Smith

Biological Sciences Theses & Dissertations

The number of shoots produced during a six week subculture of two Rhododendron sp., cultivars Rocket and Gibraltar was the same for both 16 and 24 hour photoperiods under cool white fluorescent lights, whereas significantly fewer shoots were produced under a 10 hour photoperiod for ‘Rocket.' Increasing concentrations of N₆- (2-isopentenyl)- adenine (2iP) from 0 to 32 μMin Anderson's medium resulted in proportional increases in shoot number. When shoots were cultured in the presence of indole-3-acetic acid (IAA) and 2iP, shoot multiplication was increased significantly over shoots cultured with 2iF alone. No interaction affecting shoot multiplication was …

Differential Effects Of Lithium Chloride On In Vitro Growth Of Clavibacter Michiganense Subsp. Nebraskense Depending Upon Inoculum Source, Mary L. Smidt, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The bacterium Clavibacter michiganense subsp. nebraskense (Corynebacterium michiganense subsp. nebraskense) was grown in broth cultures and inoculated into corn plants. The plating efficiency of cells from broth cultures was essentially the same on nutrient broth-yeast extract and the semiselective medium for this bacterium, CNS. However, when cells were isolated from Goss bacterial wilt- and blight-infected corn, very few were recovered on CNS compared with the amount recovered on nutrient broth-yeast extract agar. When lithium chloride was omitted from the CNS, recoveries from infected corn were nearly the same as on nutrient broth-yeast extract agar. No other ingredient of CNS …

Research Note: Do Mushrooms Have A Sex Life?, Diane Cope Peabody, Robert B. Peabody

Bridgewater Review

No abstract provided.

Using The Zadoks Growth Scale, M W. Perry, D. G. Bowran, G. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

The Zadoks growth scale, which is already used overseas as an aid to better crop management, is gradually being adopted in crop production in Western Australia.

By using the scale grain growers are able to identify the various stages of crop development, particularily those growth stages that are closely related to practices such as crop spraying where treatment too early or too late may be ineffective or damaging.

Serena And Circle Valley Medic Establishment, M A B Ewing

Journal of the Department of Agriculture, Western Australia, Series 4

Since the commercial release of the burr medics Serens in 1983, and Circle Valley ayearlater, much has been learnt about the establishment and management of these pasture legumes. When sown on suitable soils and with appropriate establishment and management techniques, these medics have the potential to dramatically change farm profitability. This results from both increased production from livestock and from improved cereal crops grown in rotation.

Nebraska Plant Distribution, David M. Sutherland, Robert B. Kaul

Biology Faculty Publications

Distribution notes based on recent collections and herbarium work are provided for 46 Nebraska plant taxa, including 43 flowering plants, two ferns, and one liverwort. The list includes several plants that are new to the State and provides range extensions within the State for many others. Several previously- published distribution records believed to be erroneous are also discussed.

Growth And Magnesium Uptake Of Tall Fescue Lines At High And Low Potassium Levels, J. H. Edwards, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Five tall fescue (Festuca arundinacea Schreb.) clonal lines with diverse root and xylem diameters were grown in nutrient solutions with magnesium (Mg) concentrations of 42, 125 and 250 µm and potassium K concentrations of 133 and 333 µm. Leaf Mg concentrations increased with increasing Mg rates at both low and high K concentrations. The tall fescue line with the largest root and xylem diameters had low leaf Mg concentrations, indicating a possible increased Mg tetany potential when consumed by cattle. The response of the K/(Mg+Ca) ratio in the plant, an indicator of tetany potential, to varying solution Mg at low …

Isolation Of Nuclei From Physarum Flavicomum: Demonstration Of Nuclear Cyclic Acid Amp Phosphodiesterase, Judith A. Bean, Maurice G. Kleve, Thomas J. Lynch

Journal of the Arkansas Academy of Science

Cyclic AMP phosphodiesterase activity in the nucleus of the myxomycete Physarum flavicomum was demonstrated by cytochemical staining utilizing electron microscopy and by enzymatic assays with tritiated cyclic AMP as the substrate. Cytochemical staining showed Physarum's plasmodial phosphodiesterase activity to be located in the nucleus, along the plasma membrane, in vesicles, and free in the cytoplasm. Nuclear phosphodiesterase, which may be cell cycle dependent, was primarily located in the nucleolus. Nuclei from three to five day old microplasmodial cultures were isolated by the method of Henney and Yee. Whole cells were collected through centrifugation and washed. Pellets were homogenized in a …

Effects Of Juglone (5'-Hydroxy-1, 4-Naphthoquinone) On The Algae Anabaena Flos-Aquae, Nostoc Commune, And Scenedesmus Acuminatus, V. Diane Randall, Jimmy D. Bragg

Journal of the Arkansas Academy of Science

Three species of algae, Anabaena flos-aquae, Nostoc commune and Scenedesmus acuminatus were selected for their sensitivity to juglone and studied for the effects of juglone concentrations of 10, 1, 0.5, 0.1 and 0.01 μg/ml upon their growth. A. flos-aquae was most sensitive, with significant inhibition by the 0.5 μg/ml concentration. N. commune was inhibited least, with significant inhibition only in the 10 μg/ml concentration. S. acuminatus was found to be moderately inhibited at the 0.5 μg/ml concentration. All species were found to be non-viable after 14 days exposure to 10 μg/ml juglone. Tests with 7 and 14 day old cells …