Effects of Seed Soaking in Fulvic Acid Solution on Seed Germination and Seedling Growth in Medicago sativa under PEG Simulated Drought Stress
The seed germination,seedling growth and physiological and biochemical indexes of stress resistance of Medicago sativa were discussed in this paper as the different treatments (CK,10％ PEG,0.03％FA+10％ PEG and 0.05％ FA+10％ PEG) were carried out in the experiments.The results showed that:(1) M.sativa seed germination rate,germinating energy,germination index,vigor index and seedling chlorophyll content,membrane stability indexcatalase (MSI) and root activity were downward trend.The growth rate of stem length and biomass were decreased,but the contents of malondialdehyde (MDA),hydrogen peroxide (H2O2),proline and soluble sugar of seedling leaves increased with the increasing of treatment duration.The activities of catalase (CAT) and glutathione reductase (GR) decreased firstly and secondly increased and finally decreased.The activities of superoxide dismutase (SOD) and peroxidase (POD) and superoxide anion (O2) increased firstly and then decreased under the simulated drought stress.The growth and development of M.sativa were inhibited significantly under the simulated drought stress and the seedling suffered from drought stress.(2)As being treated with the fulvic acid,the M.sativa seed germination rate,germinating energy,germination index,vigor index,and seedling' stem length,biomass,proline and soluble sugar contents were increased significantly.The treatment of fulvic acid also significantly alleviated the decline in the content of chlorophyll,root activity and MSI,promoted the activities of SOD POD,CAT and GR relatively,and even reduced the contents of MDA,H2O2 and the level of reactive oxygen species.It is thus clear that the seed germination and seedling growth and development of M.sativa were significantly inhibited under 10％ PEG solution simulated drought stress.In soaking seeds with fulvic acid,the content of osmotic adjustment substances was increased and enzyme activities were protected to effectively reduce oxidative damages caused by drought stress to the seedling of M.sativa,enhanced overall drought resistance of plants and maintained their normal growth.Besides,relatively significant effects were achieved by 0.05％ FA in maintaining the seed germination and seedling growth of M.sativa under drought stress.
NETL
NSTL
万方数据
维普
