Investigating physiological and biochemical

3.2.3.13 Effect of salt stress on K
+
/Na
+
 ratio in shoot
K
+
/Na
+
ratio was highly affected in the shoots of linseed genotypes by the 
application of salinity (NaCl) and K
+
/Na
+
ratio decreased significantly between 
control and 200 mM NaCl (Table 3.2.7). Linseed genotypes differed significantly 
regarding K
+
/Na
+
ratio in their shoots and the maximum K
+
/Na
+
ratio was recorded in 
the shoots of salt tolerant genotypes 637-72 and NO-303 while the minimum K
+
/Na
+
ratio was noted in the shoots of salt sensitive genotypes S-907 and C-99-3-115. At 

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87 
control, shoot K
+
/Na
+
ratio did not differ to great extent between salt tolerant and 
sensitive genotypes but increasing NaCl salinity sharply declined the K
+
/Na
+
ratio in 
the shoots of all linseed genotypes. An abrupt decrease in shoot K
+
/Na
+
ratio was 
measured at 100 mM NaCl and it decreased from 4.51-4.62 to 0.57-0.49 in 637-72 
and NO-303 genotypes and from 0.38-0.28 to 0.12-0.19 in S-907 and C-99-3-115 
genotypes respectively. At 200 mM NaCl, shoot K
+
/Na
+ 
ratio of salt tolerant 
genotypes 637-72 (0.69) and NO-303 (0.67) was more as compared to salt sensitive 
genotypes C-99-3-115 (0.19) and S-907 (0.12). Compared to root K
+
/Na
+
ratio, 
linseed genotypes showed significant variations for their shoot K
+
/Na
+
ratio at all the 
treatment levels (Table 3.2.7).
3.2.3.14 Effect of salt stress on K
+
: Na
+
 ratio in leaves
Ratio of K
+
/Na
+
was highly affected by the application of NaCl salinity in the 
leaves of linseed and a significant reduction in leaf K
+
/Na
+
ratio was noted among 
treatments. The maximum K
+
/Na
+ 
ratio was recorded in the leaves of plant grown in 
non saline control while the minimum K
+
/Na
+
ratio was recorded at highest NaCl 
level of 200 mM (Table 3.2.7). At control, leaf K
+
/Na
+
ratio did not differ to high 
extent but increasing NaCl concentration significantly decreased leaf K
+
/Na
+
ratio of 
all genotypes. The maximum reduction in leaf K
+
/Na
+
ratio occurred at the highest 
NaCl concentration of 200 mM. For example, leaf K
+
/Na
+
ratio reduced from 
15.07-10.72 to 0.21-0.20 in S-907 and C-99-3-115 genotypes with increasing salinity 
of 100 mM NaCl and from 18.55-11.51 to 0.50-0.49 in salt tolerant genotypes 
NO-303 and 637-72 at the same stress level. At 200 mM NaCl, leaf K
+
/Na
+ 
ratio of 
637-72 (0.42) and NO-303 (0.60) was higher than that of C-99-3-115 (0.05) and 
S-907 (0.09) (Table 3.2.7). 

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88 
Table 3.2.7. Effect of different levels of NaCl (mM) on K
+
: Na
+
ratios in roots, shoots and leaves of salt sensitive (S-907 and C-99-3-115) and 
salt tolerant (637-72 and NO-303) genotypes of linseed.