Effects of salinity different levels on germination indices in four varieties of sunflower (Helianthus annuus L.)

ABSTRACT: Salinity stress is one of the most common constraints to crop productivity in the world. Therefore it is of prime necessity trying to find suitable resistant genotypes to this limiting factor. In order to study of effects of salinity on germination of four genotypes of sunflower an experiment was done in in Biotechnology Laboratory, Islamic Azad University- Karaj Branch. The experiment was conducted according to completely randomized design as factorial having two factors with four replications. Four genotypes including Azargol, Euroflor, Megasun ,Hisun and salinity at five levels consisting of 0, -0.3, -0.5, -1, -1.5 MPa were applied. Results of data analysis showed that the effect of genotype was significant (p < 0.01) in all the traits nearly. Also, salinity stress effect was significant (p < 0.05) for PDW, SDW, PFW but it was significant (p < 0.01) for RDW, RFW, SFW, GP, GR, PL, RL, RL/PL ratio and SV. Furthermore, results revealed that genotype salinity level interaction was significant (p < 0.05) for PDW, RDW, RFW and for PFW, SFW, PL, RL, RL/PL ratio, SV (p < 0.05). When saline stress was increased, all of the investigated features were decreased in all the genotypes. According to the results, germination rate was more sensitive than germination percentage to salinity stress and as the levels of salinity were enhanced, germination rate was declined to 39.64 percent in -1.5 MPa. Hisun genotype had the highest value of PDW, PFW, RFW, SFW, and PL. In addition, Azargol genotype had the maximum value of RDW, SDW, RL, SV and the highest amount of GP, GR and RL/PL ratio was recorded for Euroflor genotype.