Investigating physiological and biochemical

3.2.3.16 Partitioning of K
+
 ion in linseed genotypes at different salinity 
levels 
Application of salinity decreased the K
+
accumulation in roots but increased it in 
leaves (Fig. 3.2.2). Almost all the genotypes reduced K
+
accumulation in roots and the 
minimum K
+
accumulation was observed in salt tolerant genotypes at 100 mM NaCl.
In leaves of linseed genotypes, a different behavior of K
+ 
accumulation was recorded 
with the increasing levels of salinity. It was found that salt tolerant genotypes 
accumulated less K
+
in shoots than salt sensitive genotypes. For example, salt 
sensitive genotype S-907 accumulated 36% K
+
in shoot while salt tolerant genotype 
637-72 accumulated 31% K
+
in its shoot. Similarly, C-99-3-115 accumulated more K
+
(32%) than NO-303 (31%) at 100 mM NaCl. At 200 mM, genotypes followed the 
order as NO-303 > C-99-3-115 > S-907 > 637-72 in K
+
accumulation of shoot part. In 
leaf K
+
accumulation, all the genotypes of linseed showed different pattern among 
themselves. At control, K
+
accumulation was almost equal in both salt tolerant and 
sensitive genotypes, but with the application of 100 mM NaCl, accumulation of K
+
in 
leaves increased dramatically in tolerant genotypes 637-72. At 200 mM NaCl, 
genotypes expressed a mixed behavior and followed the different order of 637-72 > 
S-907 > C-99-3-115 > NO-303 for their leaf K
+
accumulation (Fig. 3.2. 2).
 
 
Fig 3.2.2. Distribution of K
+
ion in different parts of linseed genotypes at different salinity levels 
 

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91 
 
3.2.4 Discussion 
Lab experiment regarding germination of linseed genotypes revealed that an 
increase in NaCl concentration adversely affected seed germination and seedling 
survival percentage of four linseed genotypes. It was noticed that seed germination 
was 100% under normal conditions (control) but 200 mM NaCl solution reduced seed 
germination to 84% in salt tolerant genotypes while in salt sensitive genotypes, this 
percentage was even less (78-80%). These finding clearly indicate that seed 
germination of linseed is inhibited by the presence of salts in the growth medium. The 
results demonstrated genotypic variation in seed germination responses of linseed to 
salinity stress. The genotype NO-303 attained the highest final germination 
percentages at all the salinity levels but the reduction in germination due to increases 
in salt level was much lower than in the other genotypes. The reduction in seed 
germination under salt stress might be either due to the decreased rate of water uptake 
by the seed coat (osmotic shock) and/or alterations of enzymatic or hormonal 
activities by certain toxic ion accumulation as suggested by Kaya et al. (2006) and 
Atak et al. (2006). Salt sensitive genotypes were affected more by the application of 
salt stress in terms of reduction in seed germination as compared to salt tolerant 
genotypes. Reduction in linseed germination under salt stress has also been reported 
by Guo et al. (2012).
Salt tolerance during early seedling growth was assessed on the basis of absolute 
growth at the given salt concentration relative to control. The results demonstrated 
genotypic variations in seedling growth responses of linseed to salinity stress. 
Seedling survival of all the genotypes was significantly affected by NaCl and reduced 
to 50% in salt tolerant genotypes and 40% in salt sensitive genotypes. This reduction 
in survival of linseed seedling was highly correlated to germination percentage of 
seeds. It was observed with decreasing germination, survival of seedlings also 
decreased. Croser at al. (2001) found that there was a little effect of salinity on the 
emergence of picea glauca, P. mariana and Pinus banksiana, however, later seedling 
growth was reduced. We observed the same trend that the genotypes sensitive to 
salinity at germination stage may also show sensitivity at seedling stage. 

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92 
The variation in seedling growth and survival might also be due to seed reserves 
as higher seed weight resulted in vigorous seedling growth as speculated by Soltani et