常绿岩垂草抗旱生理特性分析

选用1年生常绿岩垂草为研究对象，设置持续干旱（7、14、21、28、35d）和定期浇水2个处理，在重庆夏季连续高温干旱条件下，测定叶片的各项生理生化指标，结果显示：在干旱胁迫下，岩垂草叶片含水率与土壤含水率呈同步降低趋势；脯氨酸含量与伤害率、可溶性糖含量有相似的变化趋势，均对干旱胁迫表现出敏感的变化；可溶性糖、脯氨酸等可溶物累积，渗透调节能力随干旱程度的加强而增强，植株吸收土壤水分能力同步增强，但在持续干旱条件下，细胞膜受损严重，其对干旱的适应能力达到极限后，相关指标又会下降；丙二醛测定结果表明，在伏旱高温环境下岩垂草细胞膜受损明显且呈现梯状变化规律，浇水并不能明显改善细胞膜受损程度；浇水处理与干旱处理叶绿素含量均表现出较特异的稳步升高趋势。

Analyses on Drought Resistant Physiological Characteristics of Lippia nodi.flora

The drought resistant physiological characteristics of Lippia nodiflora were studied under the continu- ous high temperature and drought conditions in the summer season in Chongqing by measuring a set of physiological and biochemical indices of the 1 year old sample plant leaves. The sampled plants were divided into two groups, i.e. , one group treated by drought stress without watering for different periods of time （ no irrigation in 7 d, 14 d, 21 d, 28 d, 35 d）, and one group as control. The results showed that under the drought stress, the leaf water content a leaves was decreased simultaneously with soil water content. The proline content changed in similar trend with soluble sugar content and the damage rate, all showing the sensibility to the change of drought stress. With the drought intensified, the osmotic adjustment ability was promoted as the accumulation of proline and soluble sugar was increased, indicating the water absorption ability from the soil was enhanced synergically. Under the persistent drought conditions, however, afte would be damaged seriously, and that in the environment with high r the drought intensity was beyond the adaptability of the plants, the cell membrane the related indexes would decline. The determination of malondialdehyde showed temperature and lasting drought stress, the cell membrane was damaged significantly gradient variation, and the severe membrane damage could not be reversed by irrigation. The chlorophyll content of the sample leaves showed a specific steady rising trend individually to each of the two groups.