Studying the effects of different levels of salinity which caused by NaCl on early growth and germination of Lactuca Sativa L. seedling

Soil salinity is one of the most important constraints that limit crop production in arid and semi arid regions. Seed germination is a critical stage in the history of plants and salt tolerance during germination is crucial for the establishment of plants that grow in saline soils. This research was carried out in order to test the effects of different salinity levels on germination and early growth of lettuce (Lactuca Sativa L.). The experiment was carried out using completely randomized design in four replication in 2011 Zabol University laboratory Iran. The results showed that by increasing salinity, percentage and race of germination decreased, So that, in the 150 mM of salinity level, germination reached to minimized (8.33%). Other measured parameters such as plumule length, radicle length, dry and wet weight decreased as well. All the results analyzed by SAS statistical software and comparison of average had done by Duncan test on 5% possible level