Abstract:
In this study, we assessed the relative contributio
n of organic and inorganic solutes to
osmotic adjustment (OA) in three almond rootstocks
subjected to four levels of soil
salinity. The results showed that leaf water and os
motic potentials were affected by
salinity in GF677 and Bitter almond, but less so in
GN15, suggesting a higher selectivity
for K
+
and Ca
2+
against Na
+
in this latter rootstock. GN15 excluded Na
+
and accumulated
Cl
-
. Nevertheless, in this rootstock, Cl
-
and Na
+
were the main osmolytes involved in OA,
while the osmotic role of K
+
, Ca
2+
and Mg
2+
was small. Proline had the highest relative
contribution of organic solutes to OA in the leaves
of GN15 and GF677, while in Bitter
almond it was not effective. The role of soluble su
gars was rather marginal in terms of OA
in all three genotypes. All three rootstocks displa
yed a degree of OA in the presence of
high NaCl concentrations in the growth medium, but
used different osmolytes to achieve
it. Therefore, breeders should be careful in choosi
ng biochemical parameters to assess OA
capability of
Prunus
genotypes.
Keywords:
Essential cations, NaCl, Proline,
Prunus
, Soluble sugars.
