You are here
Ellison Abstract- 1993 Ellison et al (Xylem)
Ellison, A. M., K. J. Niklas, and S. Shumway. 1993. Xylem vascular anatomy and water transport of Salicornia europaea. Aquatic Botany 45: 325-339.
Abstract
The xylem anatomy, changes in vessel member diameter at stem nodes and branch junctions, and effects of these changes on water flow rates and water potential in greenhouse and field grown Salicornia europaea L. (Chenopodiaceae) have been investigated. There was a two-fold decrease in vessel diameter at branch junctions and stem nodes. In greenhouse grown plants, this decrease resulted in a 1000-fold decrease in water flow rates, and a four- to eight-fold increase in resistance to water flow across branch junctions and stem nodes relative to within-internode flow rates. However, in field grown plants, there were no differences in water flow across branch junctions and stem nodes compared with water flow within internodes. Water potentials in field plants were 3-15 times lower than in greenhouse plants. Under field conditions, hypersalinity is probably the key determinant of Salicornia water relations. Localized reductions in vessel member diameter in Salicornia appear to result from developmental changes in vasculature attending axillary bud growth. Reductions in Salicornia vessel diameter, therefore, may not be hydraulically functional adaptations per se. Rather, they may reflect a consequence of developmental branching.
