Determination of xylem water flow velocity of some Prunus shoots by dye infusion technique

Abstract

Water movement in xylem vessel presents hydraulic system. The hydraulic system may encounter embolism (cavitation) caused by environmental stresses. Tracer dyes are distributed within the xylem and can be monitored by sectioning the tissue called dye infusion technique. The current experiment determined the optimal conditions for acid fuchsin dye infusion technique to monitor the water-conducting pathways in shoots of sweet cherry and peach trees. Shoots from 18-year-old sweet cherry cultivar 0900 Ziraat grafted onto Gisela 5 and 2-year-old peach cultivar Rich May grafted onto Garnem and GF 677 were used in the experiment. Xylem functionality and xylem water flow velocity (VXW) were evaluated by dye infusion technique. The intensity of acid fuchsin staining in the shoots increased with dye concentration. In sweet cherry trees, VXW decreased with the time course and 120 mn had the lowest VXW value. In peach, VXW of GF 677 was found further compared to Garnem. The experiment showed that the dye infusion technique is reliable for the visualization of water-conduction pathways and xylem functionality. Furthermore, the technique can be used in the studies of bud dormancy break of trees and stresses.