Life Sciences Commons^™

Determination Of The Temperature Response Curves For Abscisic Acid And Its Derivatives In Economically Important Horticultural Crops, Jaleh Daie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Part I

Four-week old tomato (Lycopersicon esculentum Mill.) seedlings were exposed to different constant temperatures of 15, 25, 35, or 45 C. To determine the effect of temperature on Abscisic Acid (ABA) young and old leaves were harvested at 0, 6, 12, 24, or 48 h and free, hydrolyzable and total ABA were measured using gas liquid chromatographic methods. Temperature had a significant effect on free, hydrolyzable and total ABA in both young and old leaves. Time had a significant effect as a cubic function on all ABA measurements in old leaves but in young leaves a significant effect …

Ultrastructural Localization Of Solanidine In Potato Tubers, Shau-Ron Han

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solanine, the green substance in potato, Solanum tuberosum L., tubers, is a toxic glycoalkaloid that is a potential human health hazard. To control the formation of this glycoalkaloid a greater understanding of its site of synthesis is needed. Labelling of solanidine, a direct precursor in the biosynthesis of solanine, with digitonin may indirectly locate the site of solanine synthesis in tubers. A study using ultrastructural cytochemical techniques was initiated to explore this possibility.

Sprouted tips and peridermal complex (periderm and cortex) tissue were fixed three different ways: (1) glutaraldehyde only, (2) osmium tetroxide and glutaraldehyde, and (3) glutaraldehyde-osmium tetroxide-digitonin mixture. …

Effects Of Host Plant Patch Size And Surrounding Plant Type On Insect Population Dynamics, Lynn A. Maguire

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of the present study was to investigate how plant spatial patterns and insect behavior interact to influence the population dynamics of insects using the plants. The study included three phases: l) field experiments using collards (Brassica oleracea) and the crucifer insect fauna; 2) simulation models representing the population dynamics of an insect herbivore as functions of insect dispersal behavior and host plant patch size; and 3) model-field syntheses integrating model predictions and field variability estimates to choose an appropriate spatial scale for future field experiments or applications.

In field experiments on surrounding plant type, collards were …

Chlorophyll Fluorescence Probe Of Ultraviolet-B Photoinhibition Of Primary Photoreactions In Intact Leaves, Robert S. Nowak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Damage to primary photosynthetic reactions caused by environmental stress can be assessed by measurement of chlorophyll fluorescence induction in intact leaves. This approach was applied in studies of ultraviolet-B photoinhibition of photosynthesis in Pisum sativum L. and Rumex patientia L. leaves. At ultraviolet-B dose rates insufficient to cause inhibition of net photosynthesis, changes in the magnitude of fluorescence transients did occur, which suggested direct effects on chloroplast pigments in Pisum and inhibition of photosynthetic electron transport between the photosystems in both species. Leaves of these two species subjected to a much higher dose rate had a significant reduction of net …