东北岩高兰枝芽萌发及分枝生长特性研究

Study on the characteristics of shoot germination and branch growth in Empetrum nigrum var. japonicum

为探究濒危植物东北岩高兰枝芽萌发、分枝和枝条生长特性,以大兴安岭北部满归林业局高地林场石质山地东北岩高兰为研究对象,在疏林-林缘-石隙连续样带设置标准地,分别均等选取标准株和标准枝,调查枝芽形成的时间、类型、着生部位、萌发时间、1a枝长和枝径、样株1~5a枝的叶和不定根生长情况。结果表明:1)东北岩高兰越冬枝芽5月中下旬萌发,顶芽和近枝顶腋芽具早熟性,可在当年8月中下旬萌发,秋梢长度0.5~1.0cm,形成新枝的顶芽在密集叶包裹下越冬。2)顶端优势具多变性,形成"一优多强顶端优势"或"多强顶端优势",以适应多变的极端生境拓展种群生存空间。3)枝芽萌发抽枝分为5种类型,非近枝顶侧枝为偶见;各类型分枝率1.00~6.44,新枝数量差异较大。顶芽萌发对侧枝、特别是非近枝顶侧枝的抽生具有一定的抑制作用。4)3a枝匍匐生长且逐渐生根成不同匍匐茎克隆个体,形成与贫瘠生境中不同生存资源微生境相协调的生长发育响应策略,保证种群在总体干旱、贫瘠、多风极端生境下的不同微生境中生息繁衍。

In order to explore the germination,branching characteristics and branch growth characteristics of endangered plant Empetrum nigrum var.japonicum,the study was conducted on the rocky mountain of Gaodi Forest Farm of Mangui Forestry Bureau in the north of Daxing’an Mountains.Fixed standard plots were set up in the continuous transect of sparse forest,forest edge and rocky gap,standard plants and standard branches were selected equally to investigate the time,type,position,germination time of the buds and branches,1 year old branch length and diameter,growth of leaves and adventitious roots of branches in 1~5 year old sample trees.The results show that:1)The overwintering branch buds germinated in the middle and late May,but terminal buds and axillary buds of near branches were precocious,which could germinate in the middle and late August of the same year,and the length of autumn shoots was 0.5~1.0 cm,and the terminal buds that will form new branches overwintered under dense leaves.2)The apical dominance of terminal bud was variable,forming"one superiority,multiple strengths top dominance"or"multiple strengths top dominance"to adapt to changing extreme habitats to expand the living space of the population.3)There are 5 types of shoots,among them non-top side branches are occasionally;the branching rate of each type is 1.00~6.44,and the number of new shoots varies greatly.4)The 3 year old branches grow stolonically and root gradually into different stolon clones,forming a growth and development response strategy coordinated with the different survival resources in the poor habitat,so as to ensure the population to survive and reproduce in different microhabitats under the overall drought,barren and windy extreme habitats.