The Effects Of Different Saline-alkaline Stress On Seed Germination Of Elymus Dahuricus And Medicago Sativa

Soil salinization has become the world’s irrigated agriculture resource constraints to sustainabledevelopment.Its main function is to stress the high Na+concentrations of toxic effects,osmotic effect,high pHon three factors.Laboratory simulation of complex artificial saline habitats,so completely natural salineconditions placed under manual control,the creation of human salinity stress on a variety of complex naturalhabitats operability conditions for the comprehensive management of a large number of saline soilimprovement,restoration the use of saline resources,improving plant salt tolerance,development andutilization of halophytes provide a theoretical reference.Songnen Plain is one of the most serious soil salinization area,but also our important natural pasturesand livestock production base.Selection of strong salinity on Songnen Plain,the most representative andwidely planted Elymus quality forage grass family (Elymus dahuricus) and legume alfalfa (Medicagosativa) as the research object,according to the Songnen grassland saline composition characteristics of soilsalinity, simulate a variety of different salt concentration gradient consisting do stress on seed germinationtreatment,NaCl,Na2SO4,NaHCO3and Na2CO3according to different components and different concentrationsof salt were designed four single,a alkaline salt mixture (NaHCO3: Na2CO31:1),a neutral mixed salts (NaCl:Na2SO41:1),four kinds of mixed salt (NaCl:Na2SO4:NaHCO3:Na2CO31:1:1:1),for seed germination,seedlingroot length,plant height,root dry weight,fresh weight,dry weight and fresh weight,the indicators chlorophyllcontent,POD activity and malondialdehyde were measured,and the use SPSS.17software statistical analysisof data by changing the relationship between the various indicators,summed up the effect of different saltcomposition of growth between the two grass seed germination and each treatment,salinity differencesbetween species.For the study of seed germination of salinity,improve governance saline-alkali soil,the areasalinization of soil improvement and recovery provides a theoretical basis.The results show that:the low concentration of neutral salt solution alone can promote seed germination.Under salt stress four single alkaline salt stress (NaHCO3,Na2CO3) was stronger than the neutral salt (NaCl,Na2SO4),alkaline stress synergies Na+and pH values greater impact than the obvious.Increase the salinesolution concentration,varying degrees of suppression and prevent seed germination.With the increase of Na+and pH,Elymus seedling and root growth was affected to varying degrees,the chlorophyll content changedlittle,but MDA and POD content activity increased significantly.Alfalfa seedlings and roots to promotegrowth at low concentrations,high pH on the growth of alfalfa was significantly higher than Na+concentration (P<0.05),in alkaline solution Na2CO3,low alkali stress concentration (20mmol/L) whenobviously inhibition of germination and growth of alfalfa.The ability to withstand alkaline stress Elymus canreach100-120mmol/L.Elymus dahuricus of salinity tolerance was stronger than legume alfalfa (Medicago sativa),especiallyagainst alkaline stress (NaHCO3,Na2CO3) damage when Elymus performed significantly better than alfalfa (P<0.05).Comprehensive Evaluation of Two findings salinity ability to forage on a reasonable basis for theselective cultivation of saline-alkali soil type and planting high-quality forage with practice and guidance.