Effects of NaCl Stress on Seed Germination and Seedling Growth of Melon

The effects of NaCl stress on seed germination and seedling growth of melon were studied in order to provide theoretical basis for the varieties selection and salt resistant varieties breeding in saline-alkali area.Using Yangjiaogua,Dongfangxuemi,Heipilengzisu,Chaotianshengkaihua,Lvyuan and Hongzisugua as the materials,six NaCl concentrations were set including 0,0.5%,1.0%,1.5%,2.0% and 2.5%.The seed germination experiment was carried out using the filter culture method in laboratory,and the seedling growth was measured on mixture medium in multi-span solar intelligent greenhouse.The seed germination index(germination rate,germination potential,radicle length and hypocotyl diameter) and the seedling growth index(plant length,stem diameter,vitality index and dry weight) were determined.The salt tolerance of each variety was evaluated.The results showed that less than 1.0% of NaCl concentration had a positive effect to the seed germination.With the increasing of NaCl concentration,the germination potential and germination rate of each variety showed the downtrend,the young root growth was significantly inhibited,the seedling growth,vitality index and dry weight accumulation declined.The sensitivity to salt stress of six varieties was different.The salt tolerance of Heipilengzisu was the strongest,that of Dongfangxuemi,Lvyuan and Hongzisugua was the next,and that of Chaotianshengkaihua and Yangjiaogua was the worst.