Clipson N J W, Flowers T J
School of Biological Sciences, University of Sussex, Falmer, Brighton BN1 9QG.
New Phytol. 1987 Mar;105(3):359-366. doi: 10.1111/j.1469-8137.1987.tb00873.x.
Rates of ion transport and transpiration were measured during the day and night in whole seedlings of Suaeda maritima growing over a range of salinities, in order to calculate concentrations of sodium and potassium in the xylem during these periods. Mean sodium concentration in the xylem was maximal at 56 mol m Na with an external salinity of 200 mol m NaCl. The sodium concentration in the xylem was greater in the dark than in the light at all external salinities investigated. Comparison of the external sodium with that in the xylem indicated that sodium was more strongly excluded from the transpiration stream as salinity increased. The mean concentration of potassium in the xylem declined as external NaCl concentration increased, although selectivity for potassium increased at higher salinities. Results are discussed in relation to osmotic adjustment in S. maritima.
为了计算在这些时期木质部中钠和钾的浓度，在一系列盐度条件下生长的盐地碱蓬全株幼苗的白天和夜晚测量了离子运输速率和蒸腾速率。当外部盐度为200 mol m NaCl时，木质部中的平均钠浓度在56 mol m Na时达到最大值。在所研究的所有外部盐度条件下，黑暗中木质部的钠浓度均高于光照下。外部钠与木质部中钠的比较表明，随着盐度增加，钠从蒸腾流中被更强地排除。尽管在较高盐度下对钾的选择性增加，但随着外部NaCl浓度增加，木质部中钾的平均浓度下降。结合盐地碱蓬的渗透调节对结果进行了讨论。
