Abstract

Nineteen ecotypes of alfalfa (Medicago sativa) from Iran were evaluated for their salt tolerance based on responses of their seed germination with increasing salinity levels. Seeds of alfalfa were obtained from various parts of Iran under diverse climatic zones. The study was conducted at Putra Malaysia University during March 2008. Seeds were placed in petri dishes on filter papers immersed in solutions with six levels of salinity (0, 50, 100, 150, 200 and 250 mM) using sodium chloride as the salt. Data on seed germination performance were observed over a period of 20 days. Results showed that there were significant effects of salinity levels, ecotypes, and interaction between salinity and ecotype on germination percentage, germination rate and germination index. Reactions of ecotypes to salinity levels relative to all germination parameter were variable so that there are wide ranges of salt tolerance between the ecotypes. Ecotypes originating from the arid and cold areas were more tolerant than other areas.

Key words: Salt tolerance, Iranian alfalfa ecotypes, germination.