中文摘要：

本研究以生长在中国科学院吐鲁番沙漠植物园荒漠干旱胁迫下的梭梭属植物为研究对象，结合吐鲁番沙漠植物园几种重要环境因子，定期测定梭梭属植物生长季内同化枝净生长量、PPO活性。结果表明，两种梭梭在大气干旱严重的7～8月出现部分同化枝脱落和“生长休眠”；在整个生长季内，PPO活性与梭梭属植物生长速率呈显著正相关，PPO活性可以作为衡量梭梭属植物生长的指标之一；大气干旱是制约梭梭属植物生长的关键因子。

英文摘要：

This paper aims at Haloxylon Bunge in the desert of periphery of Turpan Eremophytes Botanic Garden, Chinese Academy of Science, under drought stress, combining variations of groundwater level of Turpan Eremophytes Botanic Garden, volume of growth of assimilational twig and change of polphenol oxidase（PPO）activity in season of growth of H. ammodendron were determined. The result indicated that from July to August, assimilational twigs of Haloxylon Bunge have abscission and growth dormancy; in the whole season of growth, PPO activity is positively interrelated with growth rate of Haloxylon Bunge. Their trends of variation are the same in the whole season of growth, so PPO activity is able to be one of indexes of judging by the growth rate of Haloxylon Bunge. However, the groundwater level is not related to the growth rate and PPO activity of Haloxylon Bunge,dry air is the key factor of restricting growth of Haloxylon Bunge, super-xerophyte.