Effect of salinity stress on germination characteristics and seedling growth of three Cantaloupe populations

In order to study the germination and seedling growth characteristics of three cantaloupe populations (Semsuri Varamin, Magase Neishabur and Green tile of Mashhad) at different salinity levels (3, 5, 7, 9 and 11 dS m-1 ), a factorial experiment was conducted based on a randomized complete blocks design with three replications in 2012 at Varamin Agricultural and Natural Resources Research Center. Results showed that three cantaloupe populations were significantly different in germination characteristics (radicle and plumule length, germination rate and fresh weight), as well as seedling growth (plant height, leaf area and fresh weight). The effect of salinity treatments on germination and seedling growth was significant, but the effect of salinity treatment and populations interactions was not significant. In germination stage, salinity tolerance index of Varamin (86%) had significant superiority to the other populations. In 3 to 11 dS m-1 salinity, fresh seedling weight decreased proportionally to salinity level by 7%. With increasing salinity levels, seedling leaf area decreased linearly. According to the results, increasing salinity more than 3 dS m-1 reduced germination rate and seedling weight of cantaloupe and therefore salinity of irrigation water should not be exceed 3 dS m-1 for proper establishment and acceptable emergence.