降香黄檀根系性状对石灰岩石砾的适应响应

Adaptive Response of Root Characteristics of Dalbergia odorifera to Limestone Gravel

以1年生降香黄檀幼苗为试验材料,采用全根和两室裂根系统,设置黑褐色石灰土和石砾2种基质,分析降香黄檀根系性状对整体和局部石灰岩石砾基质的适应性与协调关系。结果表明:与生长在全根系统黑褐色石灰土基质中的植物相比,生长于石砾基质和两室裂根系统中的植物苗高、地径增长量、生物量和根系总根长、根尖数、根平均直径和根尖基本分生组织厚度均降低,其中生长于石砾基质的显著性降低,但分枝密度均在不断增加。即在整株和局部根系组织策略上,降香黄檀主要通过优化各器官系统之间的资源分配和增加分枝密度,减小根平均直径从而增加与基质的接触面积来适应石灰岩石砾的胁迫。

Taking 1-year-old Dalbergia odorifera seedlings as experimental materials,using whole root and 2 compartment split root system,setting 2 kinds of substrates of dark brown lime soil and gravel,the adaptation strategy and coordination relationship of root traits of D.odorifera to the whole and local lime rock gravel matrix were analyzed.The results showed that compared with the plants grown in the black brown lime soil matrix of the whole root system,the plant seedling height,ground diameter growth,biomass,total root length,root tip number,average root diameter and root tip basic meristem thickness of the plants grown in the gravel matrix and 2 compartment split root system decreased,among which the plants grown in the gravel matrix decreased significantly,but the branch density increased continuously.That is,in the whole plant and local root tissue strategy,D.odorifera mainly adapts to the stress of limestone gravel by optimizing the resource allocation between various organ systems,increasing the branch density and reducing the average root diameter,so as to increase the contact area with the matrix.