干旱胁迫下梨枣抗旱性研究

为探索陕北黄土丘陵区梨枣的抗旱性与耐旱能力，以大规格盆栽梨枣（Ziziphus jujuba Mill.cv.Lizao）2年生苗木为试验材料，在连续不供水情况下研究了梨枣的萎蔫到致死过程。依据干旱缺水后枣树生长衰退过程中的特征将枣树萎蔫致死分为：暂时萎蔫、初始萎蔫、表征永久萎蔫及耐旱致死四个阶段。结果表明：梨枣的初始萎蔫系数在2.017%～3.054%之间，平均为2.494%；表征永久萎蔫系数在1.199%～1.998%之间，平均为1.489%，永久萎蔫系数在1.250%～1.489%之间；耐旱致死点为1.250%，致死时间为135±11 d。试验结果证明枣树是一种十分抗旱的树种，在半干旱黄土丘陵区枣树不会出现干旱致死。

Drought resistance of pear jujube under drought stress

In order to explore the drought-resistant ability of pear jujube (Ziziphus jujuba Mill.cv.Lizao) in Loess Plateau region of northern Shaanxi, a pot experiment was conducted with 2-year old seedlings as the material, and its process from wilting to death was investigated under continuously unirrigated condition. The degenarative process of pear jujube under unirrigated condition was classified into four periods: temporary wilting, initial wilting, apparent permanent wilting and drought caused death. The results showed that the initial wilting coefficient of pear jujube was between 2.017% and 3.054% with an average of 2.494%; the apparent permanent wilting coefficient was between 1.199% and 1.998% with an average of 1.489%; the permanent wilting coef ficient was between 1.250% and 1.489%; the drought lethal point was 1.250% and the lethal time was 135±11 days. It was concluded that pear jujube was a kind of drought-resistant fruit tree, and it could not become dead of drought in semi-arid loess hilly regions.