黑果枸杞幼苗对干旱胁迫的生理响应

以黑果枸杞（Lycium ruthenicum Murr.）幼苗为试验材料，采用称重控水的方法，设置4个水分处理水平（对照CK、轻度胁迫D1、中度胁迫D2、重度胁迫D3），研究黑果枸杞幼苗对不同程度干旱胁迫的生理生化响应。结果显示：① 随着干旱胁迫的加剧，黑果枸杞幼苗株高、基径生长量、生物量积累和叶重比在轻度胁迫下升高，中、重度胁迫下降低；根重比、根冠比在轻、中度胁迫下升高，重度胁迫下降低。② 随着胁迫时间的延长，各处理组脯氨酸（Pro）、可溶性糖含量逐渐升高，可溶性蛋白含量先降后升；丙二醛（MDA）含量先增后减再逐渐增加。③ 随胁迫时间的延长，各处理组超氧化物歧化酶（SOD）活性逐渐升高，过氧化物酶（POD）、过氧化氢酶（CAT）活性呈先升后降的趋势。综合分析认为，干旱胁迫下，黑果枸杞幼苗通过调整生长和生物量分配，减少地上部分水分散失，增加根系物质的积累，以吸收更多的水分，利用渗透调节物的积累来改变细胞渗透势，以便减少胞内水分流失。同时，通过提高保护酶活性来减弱膜脂过氧化对自身的伤害，表现出较强的耐旱性。

Physiological Responses of Lycium ruthenicum Murr. Seedlings to Drought Stress

The growth and physiological properties of Lycium ruthenicum Murr. seedlings under drought stress were studied so as to explore the defense mechanism of this plant species, reveal the mechanism of drought resistance in plants, and try to provide a theoretical basis for protecting, exploiting and utilizing the plant resources in the arid environment. L. ruthenicum Murr. seedlings were potted under four different soil moisture content levels, i.e. the optimal soil moisture content (CK), moderate drought stress (D1), moderate drought stress (D2), and severe drought stress (D3), which were controlled by weighing the soil and pots. The results were as follows: ① With increasing drought stress, the growth of plant height and base diameter, biomass and LMR of the seedlings were increased in treatment D1, but decreased in treatment D2 and D3; the RMR and root/shoot ratio were gradually increased in treatment D1 and D2, but decreased in treatment D3; ② The contents of Pro and soluble sugar were sharply increased in treatment D2 and D3; along with the drought stress time, the content of soluble protein was increased at first and then decreased; the content of MDA was increased at first, then decreased gradually, and increased again at last; ③ Along with the drought stress time, SOD activity was in an increase trend, the activities of POD and CAT were increased at first and then decreased. These results suggested that L. ruthenicum Murr. seedlings could reduce the water loss of aerial parts, increase the biomass of the roots to absorb more water, change the cell osmotic potential by accumulating the osmotic regulators to reduce the water loss within the cell and by regulating the growth and biomass allocation. Moreover, [WTBX]L. ruthenicum[WTBZ] Murr. can improve the activity of protective enzymes to weaken the role of membrane lipid peroxidation, and showed a strong drought tolerance.