Date of Award:
5-1-1980
Document Type:
Thesis
Degree Name:
Master of Science (MS)
Department:
Biology
Department name when degree awarded
Life Sciences:Biology
Committee Chair(s)
Michael A. Walsh
Committee
Michael A. Walsh
Committee
M. C. Williams
Abstract
An investigation of sieve element development in roots of Lemna minor L. was made under conditions of prolonged darkness and sucrose supplemented media. As a prelude to this study several small experiments were performed to determine whether or not sucrose in the nutrient solution is actually absorbed by the plant. Results of the dry weight analysis and osmotic values of nutrient media indicated that sucrose uptake does occur. In the prolonged darkness experiment, evidence was obtained that suggested better preservation of tonoplasts and smooth endoplasmic reticulum occurred in sieve elements that have a lowered solute concentration due to deprivation of light. Extended periods of darkness in conjunction with a sucrose supplemented medium resulted in the production of large electron opaque bodies in the developing sieve elements. The appearance of these cells suggested that tremendous surging of the protoplast had occurred. The increased solute concentration in tissue from the sucrose supplemented media caused disruption of the sieve element contents during fixation. The large electron opaque bodies found in the sieve elements may represent a channeling of the excess energy that is available to these cells into lipid storage forms.
Recommended Citation
Palmer, Julie Mitchell, "The Effects of Sucrose Concentration and Prolonged Darkness on Sieve-Element Ontogeny in Experimentally Grown Lemna minor L." (1980). Biology. 458.
https://digitalcommons.usu.edu/etd_biology/458
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