Publication
Title
Differential response of two almond rootstocks to chloride salt mixtures in the growing medium
Author
Abstract
It was examined how essential cations, Ca2+ and K+, can mitigate the toxic effects of NaCl on two different almond species (Prunus amygdalus Batsch) rootstocks, Garnem (GN15) and Bitter Almond. The tree growth parameters (water potential (I-w), gas exchange, nutrient uptake) and leaf chlorophyll (Chl) content were measured in control and NaCl-treated plants with or without KCl or CaCl2 supplements. The addition of CaCl2 and KCl to Bitter Almond trees reduced their dry weight, shoot growth and leaf number although net photosynthetic assimilation rate (A) was not affected. These results indicated that changing of photo-assimilates flux to proline and/or soluble sugars synthesis may help to increase leaf I-w. The Garnem trees also did not respond to the CaCl2 and KCl addition indicating that the plants are already getting enough of these two cations (Ca2+ and K+). In both rootstocks, NaCl in the medium reduced growth attributes, I-w, A, stomatal conductance (g (s)), and leaf Chl content. When CaCl2 and KCl fertilizers were added together with NaCl to Bitter Almond trees, leaf K+ and Ca2+ contents increased while Na+ and Cl- decreased leading to higher Ca/Na and K/Na ratios, but shoot growth was not improved and even declined compared to NaCl-treated trees. It appears that the addition of salts further aggravated osmotic stress as indicated by the accumulation of proline and soluble sugars in leaf tissues. The addition of KCl or CaCl2 to NaCl-treated GN15 trees did not increase A, leaf I-w, and shoot growth but improved ionic balances as indicated by higher Ca/Na and K/Na ratios. The reduction in A was mainly due to non-stomatal limitations in GN15, possibly due to the degradation of Chl a, unlike Bitter Almond, for which the reduction of A was due to stomata closure. The improvement in ionic balances and water status of Bitter Almond trees in response to addition of KCl or CaCl2 was apparently offset by a high sensitivity to Cl-; therefore, no-chloride salts should be the preferred forms of fertilizers for this rootstock. Both rootstocks were sensitive to soil salinity and cation supplements were of limited value in mitigating the effect of excessive salt concentrations.
Language
English
Source (journal)
Russian journal of plant physiology
Publication
2016
ISSN
1021-4437
Volume/pages
63:1(2016), p. 143-151
ISI
000370370300017
Full text (Publishers DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 05.04.2016
Last edited 27.03.2017
To cite this reference