scholarly journals Actions of Gibberellic Acid and Phytochrome on the Germination of Grand Rapids Lettuce Seeds

1974 ◽  
Vol 53 (2) ◽  
pp. 266-268 ◽  
Author(s):  
William Vidaver ◽  
A. I-Hsiung Hsiao
Keyword(s):  
Gibberellic Acid ◽  
Lettuce Seeds ◽  
Grand Rapids

Evidence for inhibitor involvement in thermodormancy of Grand Rapids lettuce seeds

1991 ◽  
Vol 1 (4) ◽  
pp. 263-267 ◽  
Author(s):  
J. G. Chris Small ◽  
Yitzchak Gutterman
Keyword(s):  
High Temperature ◽  
Temperature Treatment ◽  
Small Extent ◽  
High Temperature Treatment ◽  
Ultraviolet Region ◽  
Distilled Water ◽  
Osmotic Effect ◽  
Lettuce Seeds ◽  
Grand Rapids ◽  
Lower Temperature

AbstractProlonged imbibition and incubation of lettuce seeds at a supraoptimal temperature induces secondary dormancy. Such seeds no longer germinate when returned to conditions optimal for germination of non-dormant seeds. The possibility that inhibitors are involved in the induction of thermodormancy was investigated.Washing of thermodormant seeds restored germination to a small extent. However, continuous leaching of seeds during high-temperature treatment with distilled water, largely prevented the induction of thermodormancy. Such seeds were qualitatively similar to nondormant seeds, i.e. they required only light to germinate at a lower temperature and germinated in the dark if given GA3. The germination water from thermodormant seeds inhibited the germination of non-dormant lettuce seeds. The inhibition was not an osmotic effect. Absorbance in the ultraviolet region was higher in germination water from thermodormant seeds than that of non-dormant seeds. It is concluded that inhibitors are involved in the induction of thermodormancy of lettuce seeds.

scholarly journals Induction of Dormancy in Nondormant Seeds

1994 ◽  
Vol 119 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Anwar A. Khan
Keyword(s):  
Abscisic Acid ◽  
Lycopersicon Esculentum ◽  
Gibberellic Acid ◽  
Lactuca Sativa ◽  
Daucus Carota ◽  
Apium Graveolens ◽  
Lettuce Seeds ◽  
Moist Chilling ◽  
Dormancy Induction ◽  
Ga Biosynthesis

A gibberellic acid (GA) biosynthesis inhibitor, tetcyclacis, induced dormancy in nondormant seeds of lettuce (Lactuca sativa L.), tomato (Lycopersicon esculentum Mill.), pepper (Capsicum annuum L.), carrot [Daucus carota var. sativus (Hoffn.)], onion (Allium cepa L.), celery (Apium graveolens L.), and impatiens (Impatiens novette), as most of the seeds failed to germinate after washing under conditions that permitted germination before dormancy induction. In lettuce seeds, tetcyclacis and paclobutrazol were more effective in inhibiting germination in light than in darkness. A 16- to 24-h soak treatment with tetcyclacis was sufficient to induce dormancy in nearly all seeds. Tetcyclacis failed to induce dormancy if applied after 6 h presoak in water. Dormancy induced by tetcyclacis was released by GA4+7 (a mixture of gibberellin A4 and A7), light, and moist-chilling treatments. When GA4+7 was applied with tetcyclacis, dormancy induction was prevented under both favorable, e.g., 25C, and unfavorable, e.g., 5C, or low water potential (Ψ), germination conditions. Unlike tetcyclacis, abscisic acid (ABA) failed to induce dormancy in lettuce seeds. Thermodormancy induction in lettuce seeds at 35C was prevented by fluridone. However, neither ABA nor tetcyclacis countered its effect. Dormancy was also induced in lettuce seeds by ancymidol, flurprimidol, or paclobutrazol. Dormancy induced by tetcyclacis in pepper, tomato, carrot, and onion seeds was released by GA4+7, but not by irradiation or moist-chilling. Chemical names used: 5-(4-chlorophenyl)-3, 4, 5, 9, 10-pentaazatetracyclo [5.4.102,6.08,11]-dodeca-3, 9-diene (tetcyclacis); 1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1, 2, 4-triazole-1-yl)-3-pentanol (paclobutrazol); α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidine methanol (ancymidol); α-(1-methyl)-α-[4-(trifluoromethoxy) phenyl]-5-pyrimidine-methanol (flurprimidol); 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4 (1H)-pyridinone (fluridone).

Long-term storage of dormant Grand Rapids lettuce seeds in the imbibed state: physiological and metabolic changes

Planta ◽  
1983 ◽  
Vol 159 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Andrew D. Powell ◽  
David W. M. Leung ◽  
J. Derek Bewley
Keyword(s):  
Metabolic Changes ◽  
Long Term Storage ◽  
Lettuce Seeds ◽  
Grand Rapids ◽  
Term Storage
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