First Advisor

Richard D. Tocher

Term of Graduation

Summer 1978

Date of Publication

7-31-1978

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Biology

Department

Biology

Language

English

Subjects

Dwarf mistletoes -- Seeds, Germination, Plants -- Respiration, Photosynthesis

DOI

10.15760/etd.2730

Physical Description

1 online resource (vi, 48 pages)

Abstract

Germination, respiration, and photosynthesis in seeds of dwarf mistletoe (Arceuthobium) were studied. The effects of 1 hour soakings of seeds in aqueous solutions of 1, 2, or 3% H2O2 or 1, 2, 3, 4, or 5% Chlorox on germination of seeds were tested. Germination rates for seeds from three consecutive years (1975-1977) were obtained. Germination rates varied widely. This variance transcended subtle changes in treatment. Pretreatment of seeds with Chlorox resulted in significantly lower germination rates than those of the control. Chlorophyll concentrations were determined for seeds and aerial shoot tissue of four species. Seeds of A. douglasii had the highest chlorophyll concentration (0.39 mg/g fresh weight) while seeds of A. tsugense had the lowest concentration (0.25 mg/g fresh weight). Net O2 uptake by seeds of A. campylopodum in dark and in light was measured by manometric and polarographic methods. The mean values were 353 μ1 O2 g-1h-1 in the dark and 201 μ1 O2 g-1h-1 in the light. The difference between these rates is apparently due to O2 evolution during photosynthesis. In light the seeds can fix 43% of the CO2 produced by respiration. Experiments in which seeds were exposed to 14CO2 in light confirmed that the seeds are able to fix CO2. Extraction of seeds with ethanol showed that 97-99% of the incorporated 14C was ethanol soluble. Ten to sixteen percent of the ethanol fraction was chloroform soluble while the rest was H2O soluble. Ion exchange separation of the H2O phase showed that 11-25% of 14C activity was cationic, 15-29% anionic, and 53-67% neutral.

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Comments

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Persistent Identifier

https://archives.pdx.edu/ds/psu/16995

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