Influences of exogenous nitric oxide donor SNP on seed germination and seedling resistance of Poa pratensis under PEG simulated drought stress

Taking Poa pratensis as experimental material,the seed germination,seedling growth and stress resistance of Poa pratensis were studied under different treatments(CK,10% PEG,0.1mmol/L SNP+10% PEG and 1.0mmol/L SNP+10% PEG).The results showed that seed germination rate,germinating energy,germination index,vigor index and seedling chlorophyll content and catalase(CAT)activities decreased under drought stress compared with control,while malondialdehyde(MDA),hydrogen peroxide(H2O2),proline,soluble sugar contents and superoxide dismutase(SOD),peroxidase(POD)activity as well as superoxide anion(O-2·)increased.It showed that the growth and development of Poa pratensis were inhibited significantly under drought stress.After treated with exogenous nitric oxide donor SNP,the seed germination rate,germinating energy,germination index,vigor index,seedling chlorophyll content,proline,soluble sugar content,SOD,POD and CAT activity all increased,while the content of MDA,H2O2 and germination rate decreased.It showed that the growth and development of Poa pratensis were promoted,injury of drought stress was mitigated and drought resistance of individuals was improved.The drought resistance was significantly associated with the concentration of NO,and the protective effect was the most significant under the treatment of 0.1mmol/L SNP.