Melon (Cucumis melo L.) is an important horticultural crop often cultivated in arid and semiarid regions of the world where salinity threatens to become, or already is, a problem. Although salt stress affects all growth stages of a plant, seed germination and seedling growth stages are known to be more sensitive for most plant species. The inhibitory effect of salinity stress on seed germination is due to an osmotic effect and/or ion toxicity. Hydro-priming is a method to improve germination and emergence in the seeds of many crops, under saline conditions. Hydro-priming involved soaking of seed in water before sowing. Although the effects of hydropriming treatment on germination of some seed crops have been studied, but relatively little information is available on the invigorating of melon seed under salt stress. The aim of this study was to evaluate the effects of hydro-priming on seed germination and early seedling growth of five Iranian melon varieties and one melon cultivar ‘Galia F1’ in response to salinity. A factorial experiment was performed as a completely randomized design with four replications (25 seeds per petri dish). The first factor was six varieties of melon (Khatooni, Suski-Sabz, Kashan, Samsuri, Ghobadlu and Galia F1) and five levels of salinity. For this purpose, the seeds of melons were soaked in distilled water for 24 h at 25 °C, as hydro-priming treatment. After imbibition, the seeds were transferred into 9 cm sterile petri dishes on filter paper and then were wetted with 10 ml distilled water (control) or saline water solution at 20, 40, 60 and 80 mM NaCl. The petri dishes were incubated in a growth chamber under 16/8 h light/dark cycle at 25±2°C and relative humidity of 65±5%. Computation of germinated seeds was done daily until the end of the fourteenth day. All data were analysed by SPSS software and Duncan’s Multiple Range Test was used to determine significance of differences between variables (p<0.05). The results indicated that salin
