从旱生植物叶结构探讨其生态适应的多样性

A study on leaf structure and the diversity of xerophytes ecology adaptation

以西北地区６２种旱生植物的叶器官为研究对象，通过切片显微观察、生物学统计及模糊数学分析，探讨旱生植物生态适应的多样性，获得如下结果：①旱生植物依叶肉组成和细胞排列可划分为正常型、双栅型、环栅型、全栅型、不规则型、折迭型和无叶肉型； ②叶肉类型的演化是以正常型 与不规则型两条路线呈树枝状发展。演化较原始的偏向于中生，演化层次较高的更具适应旱生环境的能力；③旱生植物的叶肉类型与生活型具有相关性，与环境具有显著的相关性；④从模糊数学分析所获树状图看，叶性状可作为旱生植物分类的重要依据。将旱生植物的一级分类分为多浆与少浆两类是正确的；⑤旱生植物适应环境有两大趋势，即结构性状的趋同性与趋异性；⑥旱生植物适应环境胁迫有多种对策，常见有保护型、节约型、忍耐型、强壮型、逃避型等。

The leaves of 62 xerophytes in northwest China were investigated with structure observation under light microscope,the compute of biology statistics and fuzzy cluster analysis.The diversity of xerophyte′s ecological adaptation is discussed.The main experimental results are reported as follows. (1)Xerophytes may be divided into 7 types:normal,twoside plisade,ring palisade,total palisade,irregular,folding and no mesophyll in accordance with mesophyll structure and cell arrangement. (2)The evolution trend of xerophytet leaf structure is bronchial and there are 2 lines normal and irregular. (3)There are obvious interrelationships between the leaf structure and habitat,and between the leaf structure and habits. (4)According to the bronchial graph of fuzzy cluster analysis,the features of leafstructure might be an important basis,for classification of xerdphytes It seems proper to divided xerophytes into succulent and less succulent. (5)There are 2 tendencies in the xerophytes adaptation to the environments.They are differente or identical in morphological and structure. (6)Under an adaptation environment stress,xerophytes have varied strategies,such as protecting,thrift,restrain,strong and escape(avoid).