4个地理种群唐古特白刺的抗旱性系统评价

在自然条件下以分布于兰州市九州台开发区（LZJ）、张掖市临泽县（ZYL）、武威市民勤县（WWM）和酒泉市金塔县（JQJ）4个地理种群的荒漠植物白刺（Nitraria tangutorum）为研究对象,对与其抗旱性相关的光合生理、水分生理、渗透调节以及酶活性等17项指标进行测定,采用隶属函数法、灰色关联度法以及主成分分析法对不同地理种群白刺的抗旱性进行了系统地评价。结果表明,不同地理种群白刺的抗旱性强弱顺序为：JQJ〉WWM〉ZYL〉LZJ,表现出随生境条件趋于恶劣而逐渐增强趋势,这是植物通过自身生理调节对外部环境条件产生适应的结果。17项指标在白刺的抗旱性中相互制约,相互依赖,综合调节着白刺的抗旱机制,但依赖于叶黄素循环的热能耗散机制和光抑制的光保护机制在白刺的抗旱机制中占有主导地位。

Systematic Evaluation on Drought Resistance of Nitraria Tangutorum from Four Geographical Populations

The drought resistance of Nitraria tangutorum from four geographical populations,i.e.,Jiuzhoutai District of Lanzhou City( LZJ),Minqin County of Wuwei City(WWM),Linze County of Zhangye City(ZYL) and Jinta County of Jiuquan City(JQJ),are investigated regarding physiological and biochemical indices,including net photosynthetic rate,chlorophyll,soluble sugar,proline,malondialdehyde,superoxide dismutase and peroxidase.Using the methods of subordination function,grey correlation analysis and principal component analysis,the relationship of drought resistance with the indexes were evaluated systematically.The results show that the drought resistance of Nitraria tangutorum from four geographical populations was in order as JQJ> WWM> ZYL> LZJ,indicating a increasing trend of drought resistance with increasingly adverse circumstances.T his implies that the plant adapted to environmental conditions through adjusting its physiological features.T he seventeen drought resistant indices were restricted by and relied on each other in comprehensively conditioning drought resistance of Nitraria tangutorum.However,the main two mechanisms,i.e.,the xanthophyll cycle-dependent thermal energy dissipation and the photoprotective mechanism of photoinhibition,played the leading roles in the drought resistant mechanisms of Nitraria tangutorum.