摘要
百年欧洲赤松(Pinus Sylvestris L,)在休眠期,其主茎的形成层带约由5—6层细胞组成,春季,在近顶端和基部形成层差不多同时开始活动,首先形成韧皮部,3一4周后开始形成木质部,6月底—7月初,木质部形成减少,韧皮部形成有所回升。用一年生插条实验表明:具芽和去芽后施以 IAA 的插条中,形成层反应与百年大树主茎相似,而去芽后不加 IAA 的插条中,形成层只在开始时形成少量韧皮部细胞,随即进行横分裂,失去纺锤状形态。
The dormant cambial zone consisted of 5—6 cell layers in the main stem of Pinus sylvestris L. trees that were ca. 100 years old. Time of cambial reactivation was comparable at one (bot- tom) and s (top) meters above the ground. In spring, when the cambium reactivated, the num- ber of cambial cells slightly increased and phloem cells were formed. The production of xy- lem cells followed 3—4 weeks later. The formation of xylem cells decreased, whereas that of phloem cells increased between late June and early July. Cambial reaction in l-year-old cuttings that were debudded and treated aplcally with IAA in lanolin was similar to that in the ca. 100- year-old main stem. However, in debudded cuttings rreated with plain lanolin, the number of cells in the cambial zone decreased during the first week of culture, and only a few phloem ceils were formed. Later, the fusiform cambial cells of the cambial zone were divided transversely and lost their typical morphology. It is proposed that some factor(s) from roots may stimu- late the initiation of cambial cell division, because when the cambium reactivated, the number of cambial cells slightly increased in the ca. 100-year-old main stem, but decreased in the 1-year- old cuttings.
基金
瑞典农林科学委员会和中国国家自然科学基金资助项目~~
