Department of Botany and Plant Pathology, Colorado State University, Fort Collins, Colorado 80523.
Plant Physiol. 1976 Apr;57(4):612-6. doi: 10.1104/pp.57.4.612.
Grand Rapids lettuce (Lactuca sativa L.) seeds were given 35 C heat treatments to increase photodormancy in a subsequent 20 C dark period. Short heat treatments (1-5 hours) induced a significant germination percentage increase of from 16% to over 50% depending on seed lot. With longer heat treatments dark germination percentage was gradually reduced to zero. If given at the end of 35 C, far red or red followed by far red further increased the amount of dark germination.Thermodormancy also delayed red-stimulated germination by 10 hours or more when red was given following a long 35 C treatment. The presence of Pfr was required during this time since far red light remained effective in reversing at least 50% of the red stimulation for up to 16 hours compared to only 4 hours in nonheat-treated seeds.
大急流城生菜（生菜）种子经过 35°C 的热处理，以增加随后 20°C 的黑暗期的光休眠。短期热处理（1-5 小时）可使种子发芽率显著提高，从 16%提高到 50%以上，具体取决于种子批次。随着热处理时间的延长，黑暗发芽率逐渐降至零。如果在 35°C 结束时给予远红光或红光，然后再给予远红光，则黑暗发芽率进一步增加。热休眠还会延迟红光刺激的萌发时间，长达 10 小时或更长时间，当红光在长时间 35°C 处理后给予时。在此期间需要存在 Pfr，因为与未经热处理的种子相比，远红光在长达 16 小时内仍能有效逆转至少 50%的红光刺激，而仅为 4 小时。
