Seasonal changes of whole root system conductance by a drought-tolerant grape root system
View/Open
Author
Alsina, Maria Mar
Smart, David R.
Bauerle, Taryn
Stockert, Christine
Negron, Claudia
Publication date
2010-09-17ISSN
0022-0957
Abstract
The role of root systems in drought tolerance is a subject of very limited information compared with above-ground
responses. Adjustments to the ability of roots to supply water relative to shoot transpiration demand is proposed as
a major means for woody perennial plants to tolerate drought, and is often expressed as changes in the ratios of leaf
to root area (AL:AR). Seasonal root proliferation in a directed manner could increase the water supply function of
roots independent of total root area (AR) and represents a mechanism whereby water supply to demand could be
increased. To address this issue, seasonal root proliferation, stomatal conductance (gs) and whole root system
hydraulic conductance (kr) were investigated for a drought-tolerant grape root system (Vitis berlandieri3V. rupestris
cv. 1103P) and a non-drought-tolerant root system (Vitis riparia3V. rupestris cv. 101-14Mgt), upon which had been
grafted the same drought-sensitive clone of Vitis vinifera cv. Merlot. Leaf water potentials (cL) for Merlot grafted
onto the 1103P root system (–0.9160.02 MPa) were +0.15 MPa higher than Merlot on 101-14Mgt (–1.0660.03 MPa)
during spring, but dropped by approximately –0.4 MPa from spring to autumn, and were significantly lower by –0.15
MPa (–1.4360.02 MPa) than for Merlot on 101-14Mgt (at –1.2860.02 MPa). Surprisingly, gs of Merlot on the droughttolerant root system (1103P) was less down-regulated and canopies maintained evaporative fluxes ranging from 35–
20 mmol vine21 s21 during the diurnal peak from spring to autumn, respectively, three times greater than those
measured for Merlot on the drought-sensitive rootstock 101-14Mgt. The drought-tolerant root system grew more
roots at depth during the warm summer dry period, and the whole root system conductance (kr) increased from
0.004 to 0.009 kg MPa21 s21 during that same time period. The changes in kr could not be explained by xylem
anatomy or conductivity changes of individual root segments. Thus, the manner in which drought tolerance was
conveyed to the drought-sensitive clone appeared to arise from deep root proliferation during the hottest and driest
part of the season, rather than through changes in xylem structure, xylem density or stomatal regulation. This
information can be useful to growers on a site-specific basis in selecting rootstocks for grape clonal material
(scions) grafted to them.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
633 - Field crops and their production
Pages
11
Publisher
Oxford University Press
Is part of
Journal of Experimental Botany
Citation
Alsina, María Mar, David R. Smart, Taryn L. Bauerle, Felicidad De Herralde, C. Biel, Christine M. Stockert, Claudia Negrón, and Robert Savé. 2010. “Seasonal Changes of Whole Root System Conductance by a Drought-tolerant Grape Root System.” Journal of Experimental Botany 62 (1): 99–109. doi:10.1093/jxb/erq247
Program
Fructicultura
Protecció Vegetal Sostenible
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2590]
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc/4.0/