Tao K L, Khan A A
New York State Agricultural Experiment Station, Cornell University, Geneva, New York 14456.
Plant Physiol. 1979 Jan;63(1):126-8. doi: 10.1104/pp.63.1.126.
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.
用英斯特朗万能材料试验机测量了穿透完整生菜（莴苣）种子、果皮、胚乳和胚所需的力。在6、12和24小时黑暗条件下浸泡的种子，穿透胚乳大约需要0.6牛顿的力。在6小时和12小时，光照或黑暗条件下用赤霉素浸泡的种子，穿透胚乳大约需要4.2牛顿的力，而在24小时时仅需约0.15牛顿。在所有处理和时间下，穿透胚所需的力保持恒定，约为0.3牛顿。胚乳强度的变化似乎与胚根突出没有直接关系。
