关键词: 极端条件, 黄刺条, 甘蒙锦鸡儿, 白皮锦鸡儿, 狭叶锦鸡儿, 生理特性

Abstract: The physiological characteristics such as photosynthesis, transpiration, stomatic regulation, water potential variation, chlorophyll fluorescence and proline accumulation etc. of four Caragana shrub species (Caragana frutex, C. opulens, C. leucophloea and C. stenophylla) under extreme soil drought condition and post-drought irrigation condition were studied. The results show that extreme soil drought coupling with high temperature, strong solar radiation and low air humidity made the physiological activity of four shrub species be limiting, therefore no obvious responses of various physiological indexes to the microclimatic factors could be observed; post-drought irrigation enabled the physiological activity of four shrub species to resume significantly, and their responses to the changes of microclimatic factors also became noticeable. Different species had different responsiveness to soil moisture variations, C. opulens exhibited a largest amplitude, while C. leucophloea showed a smallest amplitude. Physiological responses to soil moisture conditions demonstrate that C. opulens is a hygrophilous species, C. leucophloea has a low adaptability to soil moisture variation, but C. frutex and C. stenophylla have the largest adaptability.

Key words: extreme condition, Caragana frutex, C. opulens, C. leucophloea, C. stenophylla, physiological characteristics