EXTRAORGAN FREEZING IN WINTERING FLOWER BUDS OF CORNUS-OFFICINALIS SIEB-ET-ZUCC
EXTRAORGAN FREEZING IN WINTERING FLOWER BUDS OF CORNUS-OFFICINALIS SIEB-ET-ZUCC
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DOI：
10.1111/j.1365-3040.1985.tb01407.x
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发表时间：
1985-01-01
影响因子：
7.3
通讯作者：
SAKAI, A
中科院分区：
文献类型：
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作者：
ISHIKAWA, M;SAKAI, A
以锦鸡儿花蕾为材料，研究了器官外冷冻作为提高其抗寒性的一种机制。药用植物et Zucc.差热分析（DTA）表明，C.药用植物的抗寒性主要来自于深层过冷，缓慢的降温速率也能提高小花的过冷能力。在缓慢逐步冷却（5. C h-1），小花含水量下降，鳞片（总苞片）含水量增加，导致鳞片内结冰。这是更广泛的初冬和早春芽比仲冬。在小花和鳞片之间的空间中添加硅油的花蕾也表现出类似的小花含水量减少和鳞片含水量增加。这表明，水分从小花向鳞片的迁移可能是通过花梗和花托，可能是通过它们的维管痕迹，而不是直接从小花表面以蒸汽的形式向冰槽迁移。沿着这一发现，推测了器官外冷冻的可能机制。
Extraorgan freezing as a mechanism for increasing cold hardiness was shown using flower buds of C. officinalis Sieb. et Zucc. Differential thermal analysis (DTA) revealed that florets in flower buds of C. officinalis owed their cold hardiness to deep supercooling and also that slower cooling rates increased the supercooling ability of florets. During slow stepwise cooling (5.degree. C h-1), the water content of florets decreased and that of scales (involucral bracts) increased, which resulted in accumulation of ice within the scales. This was more extensive in early winter and early spring buds than mid-winter ones. Flower buds with silicone oil in the space between florets and scales also showed a similar decrease in water content of florets and an increase in that of scales. This indicated that water migration from the florets to the scales probably took place by way of the peduncles and the receptacle, possibly through their vascular traces, and not directly from the surface of the florets to the ice sink in the form of vapor. Possible mechanisms of extraorgan freezing are postulated along with this finding.