Department of Botany, University of Missouri, Columbia, Missouri 65201.
Plant Physiol. 1969 Jun;44(6):923-8. doi: 10.1104/pp.44.6.923.
Potted cabbage plants were grown in growth chambers at 25 degrees day and 15 degrees night and hardened successively at 5, 0, and -3 degrees . Leaf growth was determined by measuring leaf area, hardiness by freezing at a series of temperatures and determining percent survival. Leaf growth increased progessively with leaf number, reaching a maximum rate of growth and final area in the tenth and eleventh leaves when the plants become potbound. Leaf growth continued at hardening temperatures of 5 or 0 degrees , the Q(10) being 2.0 to 2.5. Ability to harden also increased with leaf number, paralleling the growth rate of the leaves just before hardening as well as the growth rate and the total growth during hardening. The above results were similar whether prolonged (several weeks) or brief (24 hr) hardening was utilized.
盆栽甘蓝在 25℃日温和 15℃夜温的生长室内生长，并依次在 5℃、0℃和-3℃下进行硬化处理。通过测量叶面积来确定叶生长，通过在一系列温度下冷冻并确定存活率来确定抗寒性。叶生长随叶片数量的增加而逐渐增加，当植株长到盆满为患时，第十和第十一片叶片达到最大生长速度和最终面积。在 5 或 0 度的硬化温度下，叶生长仍在继续，Q(10)值为 2.0 至 2.5。硬化能力也随叶片数量的增加而增加，与硬化前叶片的生长速度以及硬化期间的生长速度和总生长量平行。无论是使用长时间（数周）还是短时间（24 小时）的硬化处理，都会得到类似的结果。
