Investigating physiological and biochemical

2.3.3. Agronomic traits of salt tolerance 
Although crop yield is most important criterion for the assessment of salinity 
tolerance of any crop, yet seed germination rate, root dry weight, shoot dry weight, 
number of tillers, leaf damage, leaf size, flowering, fruit size, seed size and survival 
rate have been suggested to be the very important agronomic traits of salt tolerance 
(Goudarzi and Pakniyat, 2008; Akram et al., 2011; Ghaloo et al., 2011). During salt 
stress, timing of crop development is severely affected and it is also worth mentioning 
that plant growth stages are not related to one another in terms of their salinity 

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49 
tolerance. Agronomic traits reflect the interaction of physiological mechanisms, 
genetic and environmental factors and affect of this interaction on crop growth and 
yield (Zhou et al., 2010). In different research papers, it is claimed that plant growth 
attributes should be observed and measured throughout the growth period of crop 
plants so that the salt sensitive growth stages and agronomic traits could be identified 
precisely (Erdem et al., 2001).
2.3.4 Yield and oil contents
Salt stress tolerance of oilseed crops is a complicated phenomenon as it is 
significantly modified by environmental conditions such as cultural, climatic and 
biological factors (Mahmoodzadeh, 2008). Root zone salinity affects many crops in 
terms of their growth and yield. The reduction in crop yield may be due to the 
hampered balance of plants for water and nutrients. Limited and imbalanced uptake of 
water and nutrients by plant roots is due to high osmotic stress and sodium and 
chloride toxicity (Rameeh et al., 2012). 
Linseed has very high activity of antioxidants and is being considered among the 
most important source for oil and antioxidants. This very high activity of antioxidant 
is due to the presence of ascorbic acid which is the present in huge amount in linseed 
(Westscott and Muir, 2003; Morris, 2005). Linseed possesses high omega fatty acid 
ratio and now a days, it is thought to be the richest and cheapest of omega-3 fatty acid 
(Okuyama et al., 2007). 
Many researchers claimed different results by the application of salt stress on 
some parameters of high value in crop plants. Both qualitative and quantitative 
parameters were severely affected by the application of salt stress. For example, 
increasing salinity reduced nearly all parameters of growth in Nigella sativa, amount 
of essential oil and growth of Chamomile (Razmjoo et al., 2008) and yield of lemon 
bark in terms of essential oil (Ozturk et al., 2004). Effect of salt stress on essential oil 
quality in lemon verbena showed the increased amount of geranial as salinity level 
was increased (Tabatabaie and Nazari, 2007). On the other hand, findings of the 
previous researchers are contradictory (Sarah et al., 2010). Francois (1996) observed 

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50 
that hybrids of sunflower did not show any reduction in seed yield up to 4.8 dS m
-1
salinity level while oil contents of sunflower remained unaffected by increased 
salinity up to 10.2 dS m
-1
. Rameeh et al., (2012) observed that seed yield of rapeseed 
genotypes was significantly affected and reduced by Cl
-
ion under saline conditions.