Trees

, Volume 27, Issue 3, pp 629–638

Relationship between hydraulic conductance and citrus dwarfing by the Flying Dragon rootstock (Poncirus trifoliata L. Raft var. monstruosa)

Authors

    • Instituto Valenciano de Investigaciones Agrarias
  • J. Rodriguez-Gamir
    • Instituto Valenciano de Investigaciones Agrarias
  • M. R. Martínez-Cuenca
    • Instituto Valenciano de Investigaciones Agrarias
  • D. J. Iglesias
    • Instituto Valenciano de Investigaciones Agrarias
  • E. Primo-Millo
    • Instituto Valenciano de Investigaciones Agrarias
  • M. A. Forner-Giner
    • Instituto Valenciano de Investigaciones Agrarias
Original Paper

DOI: 10.1007/s00468-012-0817-1

Cite this article as:
Martínez-Alcántara, B., Rodriguez-Gamir, J., Martínez-Cuenca, M.R. et al. Trees (2013) 27: 629. doi:10.1007/s00468-012-0817-1

Abstract

This work studied the hydraulic characteristics and physiological behavior of two trifoliate orange (Poncirus trifoliata L. Raft) varieties—Flying Dragon (FD) and Rubidoux (RT)—with contrasting size-controlling potential when used as rootstocks for citrus trees. Thus, Valencia orange scions growing on RT root system develop about 40 % more biomass than scions on FD. The anatomical study of xylem root tissue of both rootstocks showed that the number of vessels per cross-sectional area in RT almost doubled that found in FD, whereas diameter distribution did not vary significantly. Hydraulic resistance determined in rootstocks, and bud union segments were, respectively, 2- and 3.4-fold higher in trees on FD than in trees on RT. Root systems accounted for 46.5 and 55.2 % of whole-plant hydraulic resistance, whereas bud union segments represented 7.5 and 14.6 % of this parameter, the dwarfing rootstock (FD) having the highest values. Reduced hydraulic conductance in plants on FD rootstock diminished water potential in high evaporative demand periods, causing a reduction in stomatal conductance with respect to plants on RT. This leads to lower net photosynthetic CO2 assimilation, which may affect biomass production. Translocation of 13C-labeled photoassimilates from leaves to roots was lower in plants on FD than in plants on RT, indicating that in the dwarfing rootstock (FD) there may be a vascular resistance to sucrose transport at the budding union level. Findings show that reduced hydraulic conductance may be the main cause of rootstock-induced dwarfing in citrus grafted onto FD.

Keywords

Citrus rootstocksHydraulic conductanceDwarfing rootstock13C labeling

Copyright information

© Springer-Verlag Berlin Heidelberg 2012