Leaf (or assimilation branch) epidermal micromorphology of desert plant in arid and semi- arid areas of China

Aims Leaf epidermal micromorphology is an important adaptation of desert plants to arid environment. A micromorphological analysis of leaf epidermal tissue of desert plants was carried out in order to obtain qualitative and quantitative data on epidermal characteristics and to evaluate the long-term adaptive strategy of desert plants to aridity in desert conditions.
Methods The leaf (or assimilation branches) materials were sampled for more than 200 natural populations of 117 desert plant species from 74 genera and 28 families, in arid and semi-arid areas of China. The characteristics of leaf epidermal micromorphology of desert plants were then measured by scanning electron microscopy (SEM). Characteristics of epidermal cell, trichome, stomatal, cuticular wax on adaxial and abaxial surface are presented.
Important findings Leaf epidermal micromorphology of desert plants showed abundant diversity in different classification levels. The desert plants adapted to environmental stress can be divided into 11 basic morphological types according to the structure of the epidermis, and their characteristics of leaf epidermal morphology were classfied into 6 main types according to the relationships between stress resistance and structural characteristics of epidermal micromorphology and their appendages. The main epidermal appendages of desert plants (such as trichome, cuticular wax) and epidermal structures (concave-convex and papillary structure, stomata) could cooperate with each other to improve the resistance of desert plants to drought and other adverse environmental stress by resisting the strong light and reducing leaf transpiration.