Effects Of Salt Stress On Seed Germination And Seedling Growth Of Two Compositae Ground-cover Plants

The seeds of Aster alpinus L.and Achillea sibirca of the genus gaillardia are tested materials,using different concentrations(0%,0.3%,0.6%,0.9%,1.2%,1.5%NaCl,Na2SO4,MgCl2Single-salt solution and compound salt solution(NaCl,Na2SO4)to stress the Aster alpinus L,the germination percentage,germination potential,germination index and relative salt damage rate of the Aster alpinus L seeds were measured,and the leaf area,germ length and embryo root length of seedlings were determined after seed germination.The effect of salt stress on the germination of Aster alpinus L seeds was investigated,and the salt tolerant range was determined,which was beneficial to screening high salinity germplasm resources,and it was beneficial to the popularization of cover plants in saline soil.The results showed that:(1)under the stress of salt NaCl,Na2SO4,MgCl2 solution and compound salt solution,the germination of the seeds of Aster alpinus L was inhibited.With the increase of the concentration of salt solution,the germination rate,germination potential and germination index of the seed were decreased,and the relative salinity was increased.However,the inhibitory effect of different salt solution on seed germination was different,and the inhibition was:NaCl>compound salt>Na2SO4>MgCl2.(2)Under salt stress,the growth of the seedlings of alpine Aster was inhibited,and with the increase of salt concentration,the leaf area,embryo length and embryo root length of the alpine aster seedlings decreased.Among them,under the Na2SO4 stress,the seedlings could not grow and the difference was significant when the concentration reached 1.5%,and the MgCl2 stress had a great influence on the embryo root of the alpine aster seedlings,and the radicle stopped growing at the concentration of 0.6%.The effects of NaCl,Na2SO4,MgCl2 and NaCl solution were used to simulate the effects of salt stress on the yield of the seeds of Achillea sibirca using 0,0.3%,0.6%,0.9%,1.2%and 1.5%deal with.The results showed that:The effect of four kinds of salt solution on the seed germination of Yarrow was:NaCl>complex salt>Na2SO4>MgCl2.Within a certain range,the higher the salt concentration,the stronger the inhibitory effect.Salt stress inhibited seedling growth.With the increase of salt concentration,the length of radicle and embryo became smaller and the leaf area also showed a decreasing trend.