Effect of drought and salinity stresses on growth and yield of linseed genotypes

In order to study the effect of salinity on dry mass production of linseed at vegetative phase and the effects of water deficit on some agronomics, grain yield, seed oil and protein content of six linseed genotypes two experiments were carried out in 2012. In pot experiment, four levels of NaCl salt including 0 (control), 35 (moderate salinity), 70 (high salinity) and 105 mM (severe salinity) were applied onto six linseed genotypes including C1, C2, C3, B, Khorasan and 33. Plants were grown to flowering and their Na, K, Naﲯ and dry mass were measured. In field experiment, three levels of soil moisture including irrigation after 75 (control), 115 (moderate water deficit) and 145 mm (severe water deficit) evaporation from Class-A Pan were applied to linseed genotypes. Plants were grown to physiological maturity and some growth attributes and seed oil and protein content and yield were measured. In the pot experiment, results showed that Na content and Naﲯ increased and K content and dry mass decreased with progressive salinity, to the extent that the moderate salinity was sufficient to negatively affect physiological, growth and dry mass attributes of linseed. Genotypes Khorasan and C3 were proven more tolerant to salinity. In the field experiment, growth, grain yield and its attributes were decreased with water deficit in all linseed genotypes but seed oil content remained unchanged and protein content decreased by nearly four percent. Since genotypes B and C2 indicated the least decreases in their grain yield, they may be considered as more drought-tolerant genotypes. Key words: Linseed, drought, salinity, growth, Na, K, yield.