Salt stress and leguminous crops: Present status and prospects - Legumes Under Environmental Stress: Yield, Improvement and Adaptations - page 30

(GSH) content more conspicuously in Pusa Vishal than
T44. Application of 0.5 mM salicylic acid (SA) increased
nitrogen and sulphur assimilation, GSH content and
activity of APX and GR. These results indicate that SA
application alleviates the salt-induced decrease in pho-
tosynthesis mainly through inducing the activity of NR
and ATPS, and increases antioxidant metabolism to a
greater extent in Pusa Vishal than T44 (Nazar et al.,
2011).
Enhancement of salt (NaCl) tolerance by pretreat-
ment with a sublethal dose (50 mM) of NaCl was
investigated in V. radiata seedlings. NaCl stress had
drastic effects on roots compared to shoots. Accompanying
observations were also made on reductions in length
and number of root hairs and branches - roots became
stout, brittle and brown in colour. Salt stress also caused
a gradual reduction in chlorophyll, carotenoid pigment
contents and chlorophyll fluorescence intensity. SOD
and catechol peroxidase activities increased under stress
conditions in both roots and leaves, whereas CAT
activity showed an increase in roots and a decrease in
leaves. But pretreatment with a sublethal dose of NaCl
overcame the adverse effects of stress imposed by NaCl
to variable extents, by increasing growth and photosyn-
thetic pigments of the seedlings, modifying the activities
of antioxidant enzymes, reducing malondialdehyde and
H 2 O 2 content, and increasing accumulation of osmolytes
like proline (Saha et al., 2010). In another study, Saha
and his associates (2012) studied the effect of salt stress
on ion contents, Krebs cycle intermediates and Krebs
cycle regulatory enzymes in growing mung bean seed-
lings. Sodium and chloride ion contents increased in
both root and shoot whereas potassium ion content
decreased in shoots of test seedlings with increasing
concentrations of NaCl. Organic acids like pyruvate and
citrate levels increased whereas malate levels decreased
under stress in both roots and shoots. Salt stress also
variedly affected the activities of different enzymes of
the respiratory chain (Saha et al., 2012).
The response of eight parents, namely LGG 450,
VRMGG Local, LGG 460, EC 30072, VRMGG 1, LGG
410, PMB 27 and VBN 1, and five hybrids, namely
LGG450/LGG410, VRMGG Local/PMB27, LGG460/
PMB27, EC30072/PMB27 and VRMGG1/VBN1, were
studied by Sunil Kumar et al. (2012) under different
salt stress conditions (control, 4 dS/m and 8 dS/m). A
range of characters were reduced with increased
salinity levels compared to controls. These included all

biometric characters such as number of branches per
plant, number of clusters per plant, number of pods
per plant, 100 seed weight, seed yield per plant and
leaf area index; biochemical characters and biophysical
characters, namely total chlorophyll content, nitrate
reductase activity, photosynthetic rate, transpiration
rate and stomatal conductance. All the hybrids
recorded higher levels of salinity tolerance for all the
characters compared to their respective parents, except
for transpiration rate and stomatal conductance.
Interaction effects between the genotypes and salinity
levels appeared significant for most of the studied char-
acters. From the study it can be opined that salt stress
reduced all the parameters under different salinity
levels. Again among the parents and hybrids, VRMGG1/
VBN1 was found to be relatively salt tolerant (Sunil
Kumar et al., 2012).

2.4.2 Faba bean
The genus Vicia comprises about 140 species of flowering
plants. Several species of this genus are native to Europe,
North America, South America, Asia and Africa. Faba
bean, or broad bean ( Vicia faba L.), is an important pulse
crop in the Mediterranean region, west Asia, China and
Australia where it is adapted to neutral-alkaline soils. In
many cases faba bean is grown as a rain-fed crop on
saline-sodic soils where growth and yield are limited
by salinity (Tavakkoli et al., 2012). Further, faba bean
is considered particularly sensitive to abiotic stress
(in particular osmotic stress due to lack of water or
enhanced soil salinity) and often suffers from severe
yield losses (Hanafy et al., 2013).
Delgado et al. (1994) and Cordovilla et al. (1996, 1999)
compared the effect of salinity on growth and produc-
tivity and found pea and faba bean to be significantly
affected and soybean and common bean to be moder-
ately affected. Cordovilla et al. (1996, 1999), working on
the growth and symbiotic performance of faba bean
inoculated with R. leguminosarum bv. Viciae salt-tolerant
(GRA19) or salt-sensitive (GRL19) strains and treated
with 100 mM NaCl, showed that salinity significantly
decreased the dry matter yield of both shoots and roots.
The results also showed higher levels of nodule mass
and reduced nitrogen fixation in response to salinity
(Cordovilla et al., 1999).
A study was conducted by Amira and Qados (2011) to
see the effect of NaCl concentrations (0.0, 60, 120 and
240 mM) on growth, osmotic potential, chlorophyll