关键词: 草地早熟禾, 干旱胁迫, 表皮特征, 解剖结构, 光合特性

Abstract: To explore the responses of leaf epidermal characteristic,anatomical structure and photosynthetic characteristics of Poa pratensis to drought stress,six materials of P. pratensis were selected in our study,of which include three introduced varieties from the United States:'Blue Ghost' 'Comet' and 'Martha',two native wild populations from Yingxian and Hunyuan in Shanxi,and the 'Taihang' P. pratensis variety bred in our laboratory. Weighing method was used to control the subsequent evapotranspiration rate (ET),and two different water gradients (W1:60% ET,W2:100% ET) were set,the leaves of six materials were taken and sliced by free-hand sectioning and paraffin sectioning to observe the epidermal characteristics and leaf anatomical structure under optical microscope,and the photosynthetic characteristics of these materials were measured. The results showed that the anatomical structure of most P. pratensis materials under W1 treatment were significantly lower than those under W2 treatment,while there was no significant difference in the ratio of length to width of stomas in the both upper and lower epidermis of each material between W1 and W2 treatments. The intercellular CO₂ concentration of 'Blue Ghost' was the highest,which was 57.23% higher than that of the smallest Yingxian. Correlation analysis showed that net photosynthetic rate was significantly positively correlated with the leaf anatomical structure parameters and photosynthetic characteristics parameters. Drought stress caused the leaf of P. pratensis become thinner,the vascular bundle area decreased,and the photosynthetic efficiency of P. pratensis was decreased as well.

Key words: P. pratensis, Drought stress, Epidermis characteristic, Anatomical structure, Photosynthetic characteristics