Effect of water deficit stress on some physiological traits and water use efficiency of some Iranian melon landraces

In order to evaluate some Iranian melon landraces for water stress tolerance, an experiment was set out in a split plot design based on RCBD with three replicates in research field of University of Zanjan. Treatments were consisted of three irrigation levels (100, 66 and 33% of ETC) as main plots and 7 landraces of Iranian melon as subplots (‘Kali’, ‘Orshang’, ‘Mouri’, ‘Mozi’, ‘Shirazi’, ‘Ezmir’ and ‘Eyvanekey’). The results indicated that water deficit stress significantly increased proline content, peroxidase and catalase activity and reduced leaf relative water content (RWC), yield and vitamin C content. The highest water use efficiency (WUE) was observed in 66% water stress. The landraces had significant difference for physiological traits. The highest values of RWC, proline and vitamin C content were obtained in landraces of ‘Kali’ and ‘Mouri’. Also the highest POX activity, WUE and yield were obtained in landraces of ‘Ezmir’ and ‘Mozi’, respectively. According to the results ‘Eyvanekey’ and ‘Mozi’ with highest and lowest yield reduction under water deficit stress was tolerant and sensitive landraces respectively.