Effect of exogenous nitric oxide on the growth and photosynthetic characteristics of Trifolium pratense seedings under NaCl stress.

【Objective】 The objective of this study was to investigate the effects of exogenous nitric oxide on seedlings growth and photosynthetic characteristics of red clover(Trifolium pratense) seedlings under NaCl stress.【Method】 Using 50,100 and 150 μmol/L SNP(sodium nitroprusside),an exogenous nitric oxide donor as NO supply body was used to study the red clover seedling growth,net photosynthetic rate,transpiration rate and other photosynthetic indexes under 100 mmol/L of NaCl stress.【Result】 100 μmol/L SNP treatment could significantly alleviate the inhibitory effect of seedlings growth under the 100 mmol/L of NaCl stress(P0.05),and alleviate the effects of underground growth significantly better than on the ground growth;it could significantly increase net photosynthetic rate(Pn),stomatal conductance(Gs) and transpiration rate(Tr),lower intercellular CO2 concentration(Ci) in leaves of red clover.【Conclusion】 SNP can alleviate the inhibition effects under NaCl stress of the seedlings growth and photosynthesis of T.pratense significantly,and the best SNP treatment to relieve the stress of NaCl on the growth and photosynthetic characteristics of T.pratense's seedings is the concentration of 100 μmol/L.