Evaluation Of Salt Adaptability Of Mangroves Based On Electrophysiological Characteristics

Salinity and periodic tides are the main limiting factors for mangroves distribution.At present,there are many and long time-consuming indexes to characterize the salt adaptability of mangrove plants.It also builds on the serious salt damage of mangroves,which has no prediction and quantitative effect.What is more,Sodium nitroprusside(SNP)is a commonly used donor for NO.It can alleviate the damage of mangroves under various abiotic stresses.In this paper,we used the inherent electrophysiological information to quickly characterize the salt adaptability of plants,providing a method for quickly ecaluating the salt adaptability of plants.Then we synthesized the growth and physiological characteristics to verifiy the feasibility of the electrophysiological information to ecaluate the plant salt adaptability.It could be used to evaluate the salt adaptability of different mangroves accurately,and the effect of applying exogenous NO donor sodium nitroprusside(SNP)on improving the salt adaptability of mangroves.(1)This study showed that the maximum rate of changes,the rate of changes,the acceleration in solute concentration of cell sap and salt resistance index in plant leaves under salt stress could be calculated by constructing a model of water potential and cell sap solute concentration.It could not only well reflect the salt adaptation ability of mangroves,but also predict and evaluate the salt adaptation ability of different plants in different development stages and different environments.(2)By analyzing the inherent electrophysiological information,the changes of salt and water content in plant cells were discussed.The salt adaptability of different plants could be quickly ecaluated.Among them,it is better to use the inherent water conductivity(IWCpc)and inherent transport capacity(ITC)to evaluate the plant salt adaptability.(3)The salt adaptability of the three mangrove plants was as follows: A.corniculata > R.stylosa > K.candel.The inundation tolerance was as follows: A.corniculata>K.candel>R.stylosa.The results showed that the growth of the three mangroves was better under 0.2 mol/L and 4h.The salt adaptability of mangrovescould be accurately ecaluated by using the inherent electrophysiological characteristics,growth and physiological characteristics.(4)Based on this,we could ecaluate the effect of applied SNP on improving the salt adaptation ability of mangroves.Three mangroves responded differently to exogenous applied SNP.SNP concentration,light,temperature affected the rate of NO release.SNP reduced the water requirement,slowed down its water loss,and improved the salt adaptability of K.candel.However,the growth rate of K.candel was lower than that without SNP,the antioxidant enzyme activity decreased,the soluble sugar content and MDA content decreased.The effect of SNP on A.corniculata and R.stylosa was not significant,which was due to the high salt adaptability of themselves,and 0.2 mol/L did not cause serious stress on them.But the difference between this two mangroves was significant,it was that their salt management strategy were different.