The reaction of different cultivars of rice (Oryza sativa L.) to high and low salinity in vitro condition

Salinity is one of the most extensive environment stresses and is a limiting factor for the growth and development of crops، such as rice. Then، an experiment based upon completely randomized design with four low levels (0، 7. 5، 15، 22. 5) and four high of salinity (75، 150، 225 and 300 mM) with control as the first factor and nine cultivars of rice (dollars، Hasan Saraii، Mousa Tarom، Kamfiruz، Lenjan Askari، Gharib، Domsiah Mamassani، 304، Champa Yasouj) as the second factor with three replications was conducted in 2012 in the Yasouj University. Results showed that Hasan Saraii had salinity tolerance with the most germination percentage، germination rate and shoot length at high salinity levels (more than 75 mM)، and Domsiah Mamassani with the minimum of that traits had not any salinity tolerance. But in the low salinity (less than 22. 5 mM)، Hasan Saraii، Lenjan and Mousa Tarom had the highest percentage of germination. The maximum germination rate was due to Mousa Tarom and the maximum shoot length observed in Gharib variety. So it seems، if we would only consider the germination percentage، Hasan Saraii is the best variety and if the maximum germination percentage and rate are considered، the variety that would be considered is Mousa Tarom. Therefore، high salinity we should not just rely on the germination; but the germination rate should also be noted and in lower salinity due to different cultivars germination percentage، germination rate and dry weight of root should be paid much more attention.