Vanguard of empire : 15th- and 16th- century Iberian ship technology in the Age of Discovery /
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1989.
|
| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Priming or osmoconditioning is a pre-germination technique which synchronizes and accelerates the rate of seed germination. In priming, seeds are placed in osmotically adjusted solutions which restrict the availability of water to the seed. The objectives of this study were 2 fold. First, a physical characterization of seed priming including the relationship of osmotic potential, specific salt influences and duration of the effective priming treatments. Secondly, it determine if physiological changes were detectable during or after seed priming. Pepper seeds (Capsicum annuum L. cv. Keystone Resistant Giant 3) were primed with several salts and PEG 8000, at -1.08 and -1.58 MPa, through 18 days. The effectiveness of the priming treatment was dependent on the osmotic potential and length of exposure to the priming solution. No specific ion effects were observed through 12 days of priming, although in extended treatments (15 and 18 days) significant differences were observed between the salt solutions. Priming solutions with the highest osmotic potential that delays germination, induced the greatest increase in the rate of germination. Priming with salts at either osmotic potential was significantly more effective then priming with PEG 8000. Seeds were metabolically active during the priming process. Seed respiration was detected during priming and suggested there was a prolonged extension of the interval between imbibition and radicle emergence. Seed respiration studies suggested that priming delayed, rather than arrested germination, thus permitting seeds sufficient time to advance to the stage prior to radicle emergence. When radicle emergence occurred during priming, seeds lost their ability to be re-dried without germination failure. Several physiological parameters were altered by priming. Soluble protein content, de novo protein synthesis, anaerobic metabolism (as measured by aldolase and alcohol dehydrogenase activity) and lipid metabolism (as measured by isocitrate lyase activity) were significantly enhanced during priming. Increases in soluble protein and enzymatic activity observed during priming were retained to various degrees once seeds were removed from the priming solutions and re-dried. When primed seeds were germinated, higher levels of soluble protein and enzyme activity were detected. |
|---|---|
| Item Description: | Typescript (photocopy). Vita. "Major subject: History." |
| Physical Description: | ix, 320 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |