Analysis of anatomical and functional traits of xylem in Humulus lupulus L. stems
V. Gloser, M. Baláž, P. Svobodahttps://doi.org/10.17221/63/2011-PSECitation:Gloser V., Baláž M., Svoboda P. (2011): Analysis of anatomical and functional traits of xylem in Humulus lupulus L. stems. Plant Soil Environ., 57: 338-343.
Hop plants have unusually low values of the ratio between internal area of xylem conducts and leaf area, indicating that their xylem conducts solutes very efficiently. In the present study we analyzed the structure and function of xylem in stems of field-grown hop plants. Vessels of secondary xylem (SX) were more potent to conduct solutes compared to primary xylem (PRX) as they were wider (maximal/mean diameter of SX vessels in basal stem segments was on average 209/73 μm compared to 82/40 μm in PRX) and longer (up to 75 cm, compared up to 30 cm in PRX). The contribution of PRX to total Kh of the segment was on average 45.0 ± 29.9% in apical, but only 1.8 ± 0.4% in basal stem segments with well differentiated SX. We discuss differences and non-linear relationship between measured hydraulic conductivity (Kh) and Kh calculated from vessel diameters and suggest a simplified approach suitable for routine evaluation of theoretical Kh of hop cultivars.Keywords:
Hagen-Poiseuille equation; Huber value; hydraulic conductivity; vessel diameter; vessel length