Comparisons on the Xylem Embolism Characters and Anatomies of Five Rubber Clones

Maintaining an intact water column within the vascular system is vital to the water supply and vigorous growth of a plant.However,plant xylems are easily to be embolized when they are subjected to stresses such as water deficit and mechanical injury.The objective of this research is to investigate the relationships between xylem embolism vulnerability,embolism refilling ability,vessel anatomy and drought resistance of different rubber tree clones.GT1,Reyan7-33-97,PR107,Renken525,Reken523,which demonstrated diverse growth performances and drought resistances were selected as the plant materials.Embolism vulnerability curves,refilling abilities of embolized xylem from 2.5 MPa pressure collar inducements and xylem anatomies of the five clones were examined.The results indicated that the five clones were all relatively vulnerable to xylem cavitation and also easily to be refilled when the stresses were released.However,there were some divergences between clones,which could be interpreted by their xylem anatomies.Although some correlations could be found between xylem embolism traits and drought resistance of the rubber clones,more elaborative work should be conducted with the simultaneous involvement of cavitation occurrence,embolism refilling ability,stomatal regulation and drought resistance strategy of the rubber tree clones.