Abstract
The forces required to puncture intact lettuce (Lactuca sativa) seed and pericarp, endosperm and embryo were measured by the Instron Universal Testing Machine. It required about 0.6 newton to puncture the endosperm in seeds imbibed in the dark at 6, 12 and 24 hours. Endosperm of seeds imbibed in the light or in dark with gibberellic acid required about 4.2 newtons at 6 and at 12 hours and only about 0.15 newton at 24 hours. Forces required to puncture embryo at all treatments and times remained constant at about 0.3 newton. Changes in the strength of the endosperm do not appear to be related directly to protrusion of the radicle.
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Selected References
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- Borthwick H. A., Hendricks S. B., Parker M. W., Toole E. H., Toole V. K. A Reversible Photoreaction Controlling Seed Germination. Proc Natl Acad Sci U S A. 1952 Aug;38(8):662–666. doi: 10.1073/pnas.38.8.662. [DOI] [PMC free article] [PubMed] [Google Scholar]
- IKUMA H., THIMANN K. V. Photosensitive site in lettuce seeds. Science. 1959 Sep 4;130(3375):568–569. doi: 10.1126/science.130.3375.568. [DOI] [PubMed] [Google Scholar]
- Kahn A., Goss J. A., Smith D. E. Effect of Gibberellin on Germination of Lettuce Seed. Science. 1957 Apr 5;125(3249):645–646. doi: 10.1126/science.125.3249.645. [DOI] [PubMed] [Google Scholar]
- Klein S., Preiss J. W. Depth Controlled Deuteron Irradiation of Lactuca sativa Seeds. I. Effects On Germination and Growth. Plant Physiol. 1958 Sep;33(5):321–325. doi: 10.1104/pp.33.5.321. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewak S., Khan A. A. Mode of action of gibberellic Acid and light on lettuce seed germination. Plant Physiol. 1977 Oct;60(4):575–577. doi: 10.1104/pp.60.4.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rao V. S., Braun J. W., Khan A. A. Promotive effects of organic solvents and kinetin on dark germination of lettuce seeds. Plant Physiol. 1976 Mar;57(3):446–449. doi: 10.1104/pp.57.3.446. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scheibe J., Lang A. Lettuce Seed Germination: Evidence for a Reversible Light-Induced Increase in Growth Potential and for Phytochrome Mediation of the Low Temperature Effect. Plant Physiol. 1965 May;40(3):485–492. doi: 10.1104/pp.40.3.485. [DOI] [PMC free article] [PubMed] [Google Scholar]