摘要
运用生态解剖学的方法对岷江上游干旱河谷海拔梯度上乡土优势灌木——四川黄栌(Cotinus szechuanensis)的叶片解剖特征进行了比较分析.观测的解剖学参数有叶片总厚度、表皮厚度、栅栏组织厚度(P)、海绵组织厚度(S)、P/S的比值、主脉厚度(V)、主脉中直径>50μm导管分子的数目及直径.结果表明:1)四川黄栌叶片具有中生型结构特征,但在不同海拔高度存在差异,这是其适应干旱环境的结构基础.随着海拔的升高,叶总厚度、栅栏组织厚度、P/S值和主脉厚度以及导管分子数目等均呈增大趋势,而导管分子直径减小;表皮厚度、海绵组织厚度等无明显差异.2)多元统计分析显示,叶肉组织厚度和叶片总厚度主要受温和度的影响,并随着温和度的降低而增大;P/S值和导管分子数目主要与年降水量和土壤含水量的变化有关,随着水分增加,P/S值和导管分子数目增大,而导管分子直径减小.因此,岷江上游干旱河谷地区年降雨量、土壤含水量与温和度是影响四川黄栌叶片解剖结构的主要环境因子.
Leaf anatomical charactersistics and their relationship with ecological factors of Cotinus szechuanensis growing at different elevations in the dry valley of the upper Minjiang River were investigated. Measurements were made with leaf thickness, epidermal thickness, palisade mesophyll thickness, spongy mesophyll thickness, the ratio of palisade mesophyll thickness to spongy mesophyll thickness （P/S ratio）, vein thickness, vessel （ 〉50 μm） number and their diameters at the elevations of 1 670, 1 770, 1 850 and 1 950 m. The results showed that the leaves of C. szechuanensis had mesophyte characteristics which were different across elevations; these differences contributed to their adaptation to a range of drought environment; the leaf thickness, vein thickness, vessel number, palisade mesophyll thickness and the P/S ratio were increased, while vessel diameter was reduced with increasing elevation, but no significant differences in epidermal thickness and spongy mesophyll thickness were found along the elevations. The multivariate statistical analysis revealed that thickness of mesophyll and total leaf were mainly affected by temperateness. Annual rainfall and soil water content positively correlated with the P/S ratio and vessel number, while negatively correlated with vessel number. Therefore, the result of this study suggests that drought and high temperature in growth period are the main factors affecting the anatomical characteristics of C. szechuanensis leaves in the dry valley of the upper Minjian River. Fig 1, Tab 3, Ref 28
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2007年第4期486-491,共6页
Chinese Journal of Applied and Environmental Biology
基金
中国科学院知识创新工程项目(KZCX2-XB2-02
KZCX3-SW-339)
"西部之光"人才计划项目~~
关键词
干旱河谷
四川黄栌
海拔梯度
叶片
生态解剖
乡土物种
dry valley
Cotinus szechuanensis
elevation gradient
leaf
eco-anatomical
native species
