枝领
枝领（环枝组织，英文：branch collar）是树主干与枝条间类似肩膀的位子。枝领形状来自两种交替生长模式叠加而成，春天是枝条向下生长，夏季则换成主干的生长包覆其外，最终在枝条基部形成膨大的结构[1]。枝领被视为是枝条稳固的基础，其旋转与内部特征使枝条能够应付来自各方的压力[2] 。生理上，枝领也同时影响养分运输与生长模式 [3] [4]。枝领提供了生物性屏障，避免入侵与腐朽。同时可以有效的诊阻挡微生物 [1][5]。合适的修剪技术应保护枝领，以免造成腐朽或疾病等损伤树木[1]。
定义
在树艺学中，在主干和枝条间"肩"形的过度结构称为枝领或环枝组织 [6]。结构定义为从枝条基部起算，环形膨大的组织[7]。枝领或干领皆统称为枝领[6]。
形态学
随时间推移，主干扩张的形成层会渐渐覆盖新长出来的枝条组织，造成主干结构含住越来越多的枝条[1]。枝条的顶部形成"袋"状的结构，称为树裆(crotch)，其造成主干与枝条的细胞相互挤压[1]。枝领组织上形成的窄小通道和闭环都是大量贺尔蒙信号留下的路径[8]。
参考
- ^ 1.0 1.1 1.2 1.3 1.4 Shigo, Alex. How tree branches are attached to trunks. Canadian Journal of Botany. 1985,. 63(8), 1391-1401 (8): 1391–1401. doi:10.1139/b85-193.
- ^ Müller, Ulrich; Gindl, Wolfgang; Jeronimidis, George. Biomechanics of a branch – stem junction in softwood. Trees. 2006-09-01, 20 (5): 643–648. ISSN 1432-2285. doi:10.1007/s00468-006-0079-x （英语）.
- ^ Eisner, N. J.; Gilman, E. F.; Grabosky, J. C. Branch morphology impacts compartmentalization of pruning wounds. Journal of Arboriculture. 2002 [2022-03-09]. ISSN 0278-5226. （原始内容存档于2021-05-04） （英语）.
- ^ Gardiner, Barry; Quine, Christopher. The mechanical adaption of tree to environmental influences. Proceedings of 3rd Plant Biomechanics Conference: 71–82.
- ^ Nakanishi, Yoshihiro; Takesaki, Ken; Miyaji, Katsuhiko; Kitazawa, Hiroaki. Detection of Candidatus Liberibacter asiaticus from branch collars of citrus trees. Journal of General Plant Pathology. 2016-09-01, 82 (5): 248–253. ISSN 1610-739X. doi:10.1007/s10327-016-0666-7 （英语）.
- ^ 6.0 6.1 Shigo, Alex. How tree branches are attached to trunks. Canadian Journal of Botany. 1985,. 63(8), 1391-1401 (8): 1391–1401. doi:10.1139/b85-193.
- ^ TREES, ASSOCIATES and SHIGO. 2002. [DVD] Directed by A. Shigo. Durham, New Hampshire: Shigo and Trees, Associates.
- ^ Lev-Yadun, Simcha; Aloni, Roni. Vascular differentiation in branch junctions of trees: circular patterns and functional significance. Trees. June 1990, 4 (1). ISSN 0931-1890. doi:10.1007/BF00226240 （英语）.