Investigating physiological and biochemical

 
Genotypes 
Na
+
 (%) 
K
+
 (%) 
Control 
NaCl
(100 mM) 
NaCl
(200 mM) 
Control 
NaCl
(100 mM) 
NaCl
(200 mM) 
S-907 
1.45±0.10
5.04±0.07
7.99±0.02
2.86±0.06 
1.30±0.03
0.45 ±0.05
C-99-3-115 
1.43±0.05
5.62±0.09
10.11±0.06 
2.88±0.07
1.69 ±0.05
0.55 ±0.08
637-72 
1.36±0.07
7.06±0.09
12.63±0.02
3.14±0.03 
2.03±0.08
1.19 ±0.03
NO-303 
1.38±0.05 
5.75±0.08
10.31±0.06
3.16±0.07 
2.26± 0.08
2.46 ±0.05
Each value is an average of 3 replications ± SE. 

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81 
3.2.3.8 Effect of salt stress on Na
+
 contents in shoot
Accumulation of toxic ions like Na
+
and Cl
-
in shoot is one of the effective 
mechanisms of salt tolerance in different crop plants. Accumulation of Na
+
ion was 
highly affected by the application of salinity (NaCl) and shoot Na
+
contents were 
significantly increased in linseed genotypes. As described earlier, increasing NaCl 
concentration increases Na
+
concentration in growth media as well as in plant parts. 
Thus the maximum Na
+
contents were recorded at 200 mM NaCl while the minimum 
Na
+
contents were noted at control (Table 3.2.5). There was significant difference 
between genotypes for the accumulation of Na
+
in their shoots but trend of Na
+
accumulation was quite different than that observed in roots. Thus maximum Na
+
accumulation was noted in the shoots of salt sensitive genotype S-907 and C-99-3-115 
while minimum Na
+
was accumulated in the shoot of salt tolerant genotypes 637-72 
and NO-303. Under controlled conditions, linseed genotypes did not show much 
difference among themselves but increasing salinity sharply increased shoot Na
+
accumulation in all the genotypes. At 100 mM NaCl, for example, it increased from 
0.51% to 3.13% in S-907 genotype and from 0.44% to 3.09% in NO-303 while at 200 
mM NaCl, Na
+
build up in the shoots of salt sensitive genotypes S-907 (4.12%) and 
C-99-3-115 (4.51%) was more than that in salt tolerant genotypes 637-72 (3.74%) and 
NO-303 (3.35%) (Table 3.2.5). Response of salt tolerant genotypes was different 
compared to salt sensitive genotypes for their Na
+
accumulation in shoot. Overall, salt 
sensitive genotypes showed high build up of Na
+
in shoots as compared to salt 
tolerant genotypes which might have caused injurious effect on physiological and 
biochemical processes and overall growth and development of salt sensitive 
genotypes.