摘要
为探究干旱环境下植物的水势日变化特征及其与内外因素的相关性,测定了民勤绿洲耐旱植物膜果麻黄(Ephedra przewalskii)和白刺(Nitraria tangutorum)幼枝的水势、含水量及K+、Ca2+、Na+、Mg2+含量。结果表明:膜果麻黄和白刺的水势日变化趋势大体呈U型,日最低水势分别为-4.91 MPa和-4.35 MPa。膜果麻黄体内的K+和Na+含量日变化不显著,而Ca2+和Mg2+含量变化趋势呈U型;白刺体内K+、Na+、Mg2+含量日变化明显,基本呈U型,Ca2+含量日变化不明显。膜果麻黄水势与光照强度及其体内的Ca2+、Mg2+含量密切相关;白刺水势与气温、体内Mg2+含量及含水量密切相关。影响这2种植物水势的因子并不完全一样,但Mg2+离子对二者的水势均具有显著影响。
In order to explore the diurnal variation of water potential of plants in arid area,and the correlation between water potential of plant with external environmental factors and contents of positive ions in plants,water potentials and the contents of four kinds of cations(potassium,calcium,sodium and magnesium ions)in the two drought-endurable plants Ephedra przewalskii and Nitraria tangutorumfrom the Minqin Oasis were determined and water contents of the two plants and soil water content were measured too.The results showed that diurnal changes of water potential of the two kinds of plants both followed U-shaped curves.Daily minimum values of water potential in E.przewalskii and N.tangutorumplant were-4.91 MPa and-4.35 MPa,respectively.No significant differences were observed on diurnal changes of potassium and sodium contents in E.przewalskii,but the changes of calcium and magnesium contents both showed U types.Diurnal variations of potassium,sodium and magnesium contents were obvious in N.tangutorum,followed U types,and only the change of calcium content was not significant.Regression analysis showed that the change of water potential of E.przewalskii was closely related with its calcium and magnesium contents and light intensity.The water potential of N.tangutorum was well related to magnesium ion and water contents in the plant,and temperature.Regulation factors for water potential of the two kinds of plants were not exactly the same,but the effects of magnesium ion on both water potentials were significant.
出处
《中国沙漠》
CSCD
北大核心
2015年第2期385-392,共8页
Journal of Desert Research
基金
国家自然科学基金项目(31160118
31460162
30960060)
