关键词: 柠条, 中间锦鸡儿, 小叶锦鸡儿, 气体交换特征, 调节机制

Abstract: When soil water supply was adequate, the photosynthetic rate (Pn), transpiration rate (E) and stomatal conductance (Gs) of Caragana korshinskii, C. intermedia and C. microphylla increased greatly. The Pn and Gs values of the three shrubs were in order: C. intermedia > C. microphylla > C. korshinskii; the E values in the order: C. korshinskii > C. intermedia > C. microphylla. The diurnal chlorophyll fluorescence parameters of C. korshinskii, including Fv/Fo, Fm/Fo and Fv/Fm, were the highest and no significant reduction was observed in the daytime; the corresponding parameters of C. intermedia were the lowest and appeared low valley between 13:00~17:00, which indicated an obvious light suppression to the photosynthesis. The measured values of C. microphylla fluctuated between that of the above two species. The light suppression to the photosynthesis of the three shrubs terminated in the evening. Among the three shrubs, C. intermedia had a higher chlorophyll content, while the corresponding values of C. korshinskii and C. microphylla were approximate; the diurnal mean carotene content of C. intermedia was the highest, while C. korshinskii and C. microphylla had an approximate carotene content values. The water potential of C. korshinskii in a day was the lowest and fluctuated gently, while the corresponding values of C. intermedia and C.microphylla were higher and had larger diurnal reduction amplitude. Furthermore, they reached a lowest value between 15:00~17:00. The proline content of C. korshinskii in the daytime increased significantly, the corresponding value of C. intermedia also slightly increased but the increase in proline content of C. microphylla was not noticeable. In terms of the proline contents of the three shrubs they were arranged in the order: C. korshinskii > C. intermedia > C. microphylla.

Key words: Caragana korshinskii, C. intermedia, C. microphylla, gas exchange characteristics, regulation mechanism