Investigating physiological and biochemical

 

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82 
 
 
Table 3.2.5. Effect of different levels of NaCl (mM) on Na
+
and K
+
contents in shoots of salt sensitive (S-907 and C-99-3-115)
And salt tolerant (637-72 and NO-303) genotypes of linseed.
 
Genotypes 
Na
+
 (%) 
K
+
 (%) 
Control 
NaCl
(100 mM) 
NaCl
(200 mM) 
Control 
NaCl
(100 mM) 
NaCl
(200 mM) 
S-907 
0.51±0.02
3.13±0.04
4.12±0.08
1.64±0.03 
1.17±0.09
0.49 ±0.06
C-99-3-115 
0.46±0.03
3.80±0.07
4.51±0.06 
1.65±0.05
1.06 ±0.07
0.88 ±0.06
637-72 
0.45±0.03
2.97±0.01
3.74±0.06
2.01±0.07 
1.71±0.02
2.57 ±0.08
NO-303 
0.44±0.02 
3.09±0.03
3.35±0.03
2.03±0.09 
1.53± 0.05
2.23 ±0.02
Each value is an average of 3 replications ± SE. 

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83 
3.2.3.9 Effect of salt stress on K
+
 contents in shoot 
Highly significant effects of treatments, genotypes and their interaction were 
observed when K
+
concentration was determined in the shoots of linseed genotypes. 
K
+
acts as inorganic osmoticum in some plants for regulation of osmotic potential of 
intra cellular structure and hence plays its role in retaining water contents within the 
plant body. Concentration of K
+
was highly affected in the shoots of linseed by the 
application of salinity (NaCl). The maximum K
+
contents were recorded in 200 mM 
NaCl in salt tolerant genotypes while the minimum K
+
contents were observed in salt 
sensitive genotypes at the same treatment (Table 3.2.5). Genotypes also showed 
significant difference for their K
+
accumulation in shoot and the maximum K
+
contents were noted in salt tolerant genotype 637-72 while the minimum K
+
contents 
were recorded in S-907 genotype. In control, K
+
concentration was highest (2.03%) in 
the shoot of NO-303 genotype while lowest concentration of K
+
(1.64%) was noted in 
the shoot of S-907 genotype. Application of salt stress progressively reduced the K
+
contents in the shoots of salt sensitive linseed genotypes and the maximum reduction 
in K
+
contents occurred in same genotypes at 200 mM NaCl but . At 100 mM NaCl, 
decrease in shoot K
+
contents ranged from 1.53% to 1.71% in NO-303 and 637-72 
and from 1.06% to 1.17% in S-907 and C-99-3-115 respectively. Similarly, at 200 
mM NaCl, K
+
accumulation in the shoots of salt tolerant genotype 637-72 (2.57%) 
was the maximum followed by NO-303 (2.23%) while salt sensitive genotype S-907 
had the minimum shoot accumulation (0.49%) of K
+
followed by C-99-3-115 (0.88%) 
(Table 3.2.5). Salt tolerant (NO-303 and 637-72) and salt sensitive genotypes 
(C-99-3-115 and S-907) differed significantly for their K
+
accumulation in their 
shoots. Genotype S-907 and C-99-3-115 reduced the K accumulation with increasing 
salinity but On the other hand, salt tolerant genotype 637-72 and NO-303 accumulated 
low K
+
in its shoot at control but with the application of salinity its shoot K
+
accumulation firstly decreased dramatically and then increased to the maximum level.