First insights into the functional role of vasicentric trhacheids and parenchima in eucalyptus species with solitarya vessels: Do they contribute to xylem efficiency or safety ?

MARIA E. FERNANDEZ; ARIEL G. MEYRA; JOSE A. BAROTTO; ALEJANDRO MARTINEZ MEIER; JAVIER GYENGE; SILVIA MONTEOLIVA

TREE PHYSIOLOGY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2016 vol. 36 p. 1485 - 1497

0829-318X

p { margin-bottom: 0.25cm; line-height: 120%; }Therelationship between hydraulic conductivity (ks) and vulnerability tocavitation (VC) with size and number of vessels has been studied inmany angiosperms. However, few are the studies linking other celltypes (vasicentric tracheids (VT), fibre-tracheids, parenchyma), withthese hydraulic functions. Eucalyptusis one of the most important genera in forestry worldwide. Itexhibits a complex wood anatomy, with solitary vessels surrounded byVT and parenchyma, which could serve as a good model to investigatethe functional role of the different cell types in xylem functioning.Wood anatomy (several traits of vessels, VT, fibres and parenchyma)in conjunction to maximum ks and vulnerability to cavitation werestudied in adult trees of commercial species with medium to high wooddensity (E.globulus,E.viminalisand E.camaldulensis).Traits of cells accompanying vessels presented correlations withfunctional variables suggesting that they contribute to bothincreasing connectivity between adjacent vessels -and, therefore, toxylem conduction efficiency- and decreasing the probability ofembolism propagation into the tissue, i.e. xylem safety. All threespecies presented moderate to high resistance to cavitation (mean P50values= -2.4 to -4.2 MPa) with no general trade-off betweenefficiency and safety at the interspecific level. Results in thesespecies do not support some well-established hypotheses of thefunctional meaning of wood anatomy.