Sprout Water Potentials and the Influencing Factors in Ephedra przewalskii and Nitraria tangutorum
Received date: 2014-11-10
Revised date: 2014-12-22
Online published: 2015-03-20
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 tangutorum from 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. tangutorum plant 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.
Key words: water potential; Ephedra przewalskii; Nitraria tangutorum; cations
Chen Mingkai , Chang Guohua , Chen Yingquan , Gao Tianpeng , Shi Xiaoni . Sprout Water Potentials and the Influencing Factors in Ephedra przewalskii and Nitraria tangutorum[J]. Journal of Desert Research, 2015 , 35(2) : 385 -392 . DOI: 10.7522/j.issn.1000-694X.2014.00191
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