Effect of exogenous melatonin on germination and seedling growth of melon(Cucumis melo L.)under salt stress
The aim of studying the effects of different concentrations of exogenous melatonin treatment on the germination and seedling growth of balloon cucumber under salt stress is to find the most suitable concentration of exogenous melatonin that can promote the germination of balloon cucumber seeds and alleviate the salt tolerance of seedlings.The experimental material is the melon variety Baogua.For the seed experiment,seeds were soaked in different concentrations of melatonin(MT)including 0 μmol/L MT(T0),50 μmol/L MT(T1),100 μmol/L MT(T2),200 μmol/L MT(T3),and 300 μmol/L MT(T4).A 180 mmol·L-lNaCl solution was used as the germination solution to simulate a salt stress environment.A complete blank control group(CK,0 μmol/L MT+0 mmol/L NaCl)was also set up.For the seedling experiment,a plug tray cultivation method was adopted.Seedlings were subjected to salt stress by watering with 180 mmol/L NaCl,and sprayed with 0 μmol/L MT(MT0)and 100 µmol/L MT(MT100)as the treatment groups.A complete blank control group(CK,0 μmol/L MT+0 mmol/L NaCl)was also set up.The salt tolerance alleviation effects of each treatment group were discussed by measuring and analyzing the growth,physiological,and biochemical indicators of each treatment group.The experimental results showed that salt stress significantly reduced the germination potential,germination rate,germination index,and other indicators of'Baogua'seeds.Similarly,the chlorophyll content,leaf length,leaf width,POD activity,and CAT activity of the seedling leaves were also reduced,while the malondialdehyde(MDA)content increased.After pre-treating the seeds with exogenous melatonin soaking and spraying exogenous melatonin on salt-stressed seedlings,all indicators showed some degree of alleviation.Among them,the T2 treatment significantly promoted seed germination-related indicators compared to the T0 group.The MT100 treatment group showed 30.92％increase in chlorophyll content compared to the MT0 treatment group,40.22％and 26.24％increase in POD and CAT activities respectively,and 26.23％reduction in MDA content.The comparison of the test results from various treatment groups indicated that 100 μmol/L MT was the optimal concentration for promoting germination of Baogua melon seeds,and it had a significant effect on alleviating salt stress in seedlings suffering from salt injury.
万方数据
维普
