摘要
石斛(Dendrobium nobile Lindl.)为兰科多年生附生性草本植物,特化的假鳞茎是其营养贮藏器官,通过假鳞茎可实现克隆生长。该研究以野外调查发现的石斛株丛为研究材料,比较不同等级株丛假鳞茎合轴生长和高位腋芽的差异,分析高位株丛的定植方式,探讨石斛株丛生长及营养繁殖对附生环境的适应策略。结果显示:(1)石斛株丛的生长和扩大通过合轴生长的营养繁殖方式进行,假鳞茎基部具有2~3个储备芽,每年萌发1~2个新芽,随着生长年限的增加,形成大小不一的株丛。(2)株丛具有典型的高位腋芽营养繁殖特性,且主要形成于假鳞茎密集和老根密布的大株丛。(3)高位株丛母茎一端附着于附主树种上,在母茎软化和高位株丛的重力作用下,缩短了高位株丛与附主的距离,使其根系能够触及附主,完成高位株丛的定植。研究表明,附生植物石斛通过假鳞茎合轴生长的营养繁殖方式来增强并延续株丛寿命,高位腋芽的频发是株丛假鳞茎对拥挤等逆境的响应,高位株丛的定植依赖于母茎,这也是石斛对附生环境的一种生态适应策略。
The plant of Dendrobium nobile Lindl.is a perennial herbaceous epiphytic orchids.Its specialized pseudobulb used as nutrient storage organ and can be realized in the clonal growth,of which plays an important role in the vegetative propagation.This research studied the wild plant,compared to the difference of sympodial growth and high lateral bud on different levels of pseudobulb,and analyzed the engraftment way.Meanwhile,the adaptive strategy of its growth and vegetative propagation were discussed.Mainly results showed as following：（1）the seedlings grow and expand via vegetative propagation of sympodial.With 2-3bud in reserve of pseudobulb,it sprouts 1-2new bud and forms different seedlings as time goes on.（2）The seedlings have typical high lateral reproductive characteristics and mainly form from dense pseudobulb and roots.（3）The stems of high seedlings attach to the tree trunks,shorten the distance and complete engraftment way by stem intenerate and gravity.The results show that the pseudobulbof Dendrobiumvia sympodial vegetative propagation to enhance and extend lifetime.The adversity such as crowding of pseudobulb respond by frequent high bud germinating,and it is an ecological adaptive strategy of epiphytic environment like engraftment way of high seedlings depending on stem.
出处
《西北植物学报》
CAS
CSCD
北大核心
2017年第4期797-804,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家农业科技成果转化重点项目(cstc2014jcsf-nycgzhB80001)
重庆市科技惠民项目(2013GS500102-D2014-2)
重庆市科委自然科学基金项目(cstc2012jjA10140)
关键词
石斛
附生植物
假鳞茎
合轴生长
高位腋芽
营养繁殖
Dendrobium nobile Lindl.
epiphyte
pseudobulb
sympodial growth
high lateral bud
vegetative propagation
