Drought stress is one of the most important limiting factor for growth and production of crop plants worldwide. Since arid and semi-arid climate and then water deficit is prevalent in Iran, this research was aimed at studying the impact of irrigation regimes on gas exchange properties, proline content, soluble carbohydrates, yield and yield components of four genotyes of oilseed pumpkin. A 4-replicate split plot, randomized complete block experiment was conducted at the Lavark Research Farm, College of Agriculture, Isfahan University of Technology-Isfahan, Iran at 2010. Three irrigation regimes based on evaporation from a Standard justify; MARGIN: 0in 0in 0pt; unicode-bidi: embed; DIRECTION: ltr; tab-stops: 273.55pt; mso-line-height-alt: .6pt" Key words: Oilseed pumpkin, drought, proline, gas exchange properties, yield .
