Life Sciences Commons^™

The Effects Of Silica, Nitrogen, And Phosphorus Limitation On The Biochemical Composition Of Cyclotella Meneghiniana Kütz: An Experimental Analysis , David Fred Millie

David F. Millie

The effects of silica, nitrogen, and phosphorus limitation on the amount of cellular lipid, fatty acid, glucan, protein and chlorophyll of Cyclotella meneghiniana Kutz. were investigated in batch and semi-continuous culture experiments. In batch cultures, cells were removed from nutrient-replete media and resuspended in nutrient-deficient media according to a 2('3) factorial design in fractional replication. Cells were analyzed 3 and 9 days after transfer to treatment media. Of the 3 nutrients, only silica had a significant effect on a biochemical variable. Silica deficiency caused a significant increase (300%) in the amount of cellular protein. Cellular protein was also significantly different …

Wild Rides And Wildflowers: Philosophy And Botany With Bikes, Scott Abbott, Sam Rushforth

Scott Abbott

This book bears only passing resemblance to any book we have read to date. We hope it is comical, perhaps in ways that will remind readers of NPR’s “Car Talk,” where listeners share the good natured and sometimes acidic banter between brothers who also know a lot about cars. We hope it is moving, not in the extended ways Terry Tempest Williams often achieves, but through surprising comments and stories that accompany the bike rides and that, over the course of four years, add up to a larger picture. We hope it is informative, not in the comprehensive way John …

Uses Of Wild Plants In Ndumba, Eastern Highlands Province, Terence Hays

Terence Hays

For Papua New Guineans,l as well as for those who wish to understand them better, traiditional knowledge of the local natural environment is a priceless resource. In the face of increasing commitments to a cash economy, however, many communities are rapidly losing their awareness and appreciation of the rich animal and plant worlds which are immediately available to them. As Powell has recently observed (1976), the recorded information regarding traditional plant knowledge and uses has tended to be widely-scattered in the literature and relatively difficult to access, especially for those who stand to benefit the most from it. A recent …

Laboratory Method To Estimate Rain-Induced Splitting In Cultivated Blueberries, Kenneth Curry

Kenneth J. Curry

Preharvest rainfall that occurs when fruit are fully ripe or approaching full ripeness can result in detrimental fruit splitting in rabbiteve and southern highbush blueberries. This study was initiated to develop a laboratory method to model rain-related incidence of splitting in cultivated blueberries with the goal of predicting the incidence of splitting in blueberry cultivars and selections. Multiyear field surveys of rabbiteye and southern highbush cultivars show that the incidence of rain-related splitting is strongly cultiva-dependent. Laboratory values for forced splitting and naturally occurring rain-related field splitting data show a strong correlation indicating that the incidence of fruit splitting can …

Effect Of Cercosporella Rubi On Blackberry Floral Bud Development, Kenneth Curry

Kenneth J. Curry

Rosette, caused by the fungus Cercosporella rubi, is an important blackberry disease in the southeastern United States. This disease severely reduces fruit production, and its management has been erratic due to a limited understanding of the host-pathogen relationship. In this study, we expand on previous histological investigations of the development of C. rubi on blackberry at tissue and cellular levels from floral bud initiation through senescence of the flower. Symptomatic and asymptomatic floral buds were examined with light microscopy and both scanning and transmission electron microscopy (SEM and TEM, respectively). Fungal development on the surface of floral buds was …

Osmophore Development In Stanhopea Anfracta And S. Pulla (Orchidaceae), Kenneth Curry

Kenneth J. Curry

The developmental anatomy and morphology of the floral scent glands (osmophores) were examined daily from the late bud stage to post-anthesis, for 2 species which are considered to be at opposite poles in the evolutionary development of the genus. The osmophore of S. anfracta was studied using morphometric techniques to estimate volume density of selected cellular inclusions, whereas the osmophore of S. pulla was examined qualitatively. The volume density of starch/amyloplast in S. anfracta remained relatively constant throughout most of the two-day flowering period as did the degree of cell vacuolation. The flower of S. pulla lasts only one day, …

Improved Microassays Used To Test Natural Product-Based And Conventional Fungicides On Plant Pathogenic Fungi, Kenneth Curry

Kenneth J. Curry

Interpretive Summary: New effective fungicides are needed to control fungal pathogens that have developed resistance to currently used fungicides or to replace fungicides that have lost their registration for use on certain crops. Natural products are one source of these new fungicides. Prospective new fungicides are screened in vitro to identify products which inhibit germination of fungal conidia or prevent normal growth of fungal hyphae. In this paper we established standard conditions that improved the in vitro micro titer assays used in the initial screening of natural products as potential fungicides. The simple step of washing fungal spores prior to …

Comparative Genetics Of Seven Plants Endemic To Florida’S Lake Wales Ridge, Eric S. Menges, Rebecca W. Dolan, Rebecca Yahr, Doria R. Gordan

Rebecca W. Dolan

Here we submit that mathematical tools used in population viability analysis can be used in conjunction with floristic and faunistic surveys to predict changes in biogeographic range. We illustrate our point by summarizing the results of a demographic study of Lobelia boykinii. In this study we used deterministic and stochastic matrix models to estimate the growth rate and to predict the time to extinction for three populations growing in the Carolina bays. The stochastic model better discriminated among the fates of the three populations. It predicted extinction for two populations in the next 25 years but no extinction of the …

Tailor-Made Composite Functions As Tools In Model Choice: The Case Of Sigmoidal Vs Bi-Linear Growth Profiles, Winfried Peters, Tobias Baskin

Winfried S. Peters