Abstract:
Salt stress constitutes on
e of the most significant environmental constraints that limit
legume production, especially in arid and semi
-
arid regions. This study aimed to evaluate
the effect of salt stress (0, 60, and 120 mM of NaCl) on growth, nodulation process,
nitrogen uptake an
d mineral nutrition content of
Vicia faba
L. plants inoculated with
native Moroccan rhizobia isolated from root nodules of faba bean plants grown in the
Marrakech
-
Haouz region. Three
Rhizobium leguminosarum
strains (RhOF34, RhOF125
and RhOF15), which had d
ifferent tolerance to salinity, were used to inoculate faba bean
plants. The results showed that chronic exposure to salinity affected growth and symbiotic
parameters of
V. faba
differently
.
Shoot biomasses were reduced under salinity stress
especially in
the plants inoculated with the salt sensitive strain (RhOF15). The nodulation
of faba bean roots sharply decreased under 120 mM salt treatment, particularly with the
sensitive
Rhizobium
strain. The total nitrogen content decreased with increasing salinity,
except for the plants inoculated with the tolerant strain RhOF34, which kept a high
nitrogen content. Sodium and calcium concentration increased sharply in plant tissues
with increasing salt stress, while the potassium concentration decreased. RhOF34 stra
in
reduced Na
+
, Ca
2+
and K
+
absorption by faba bean plants. Inoculation with the salt
tolerant strains RhOF125 and RhOF34 led to an increased plant biomass, nodules
number, and nitrogen content; and seemed to protect faba bean plants against the toxic
effe
cts of salinity.
Keywords:
M
ineral nutrition,
Plant nutrition
, R
hizobia
,
Salt tolerance, Salt tolerant strains.
