Study On Physiological Characteristics Of Atriplex Canescens Under NaCl And Na₂SO₄ Salt Treatments

Under the background of increasing salinization of the land,the cultivation of salt-tolerant plants are becoming increasingly important.This paper chooses Atriplex canescens of Chenopodiaceae as the research object,choosing Qaidam saline region of Qinghai Province as the research area.Using indoor pot control method,NaCl and Na2SO4 salt treatments were respectively applied to Atriplex canescens and set 0,100,200,300 and 400 mmol·L-1 concentration gradient.Measuring the growth index,penetration ability and photosynthetic characteristics of Atriplex canescens under different salt condition.To study the effects of salt treatment on the growth and physiological differences of Atriplex canescens.Get the following main conclusions:(1)In this study,the soil moisture content at the maximum net photosynthetic rate was used as the optimum moisture for the growth of Atriplex canescens seedings,fitting the net photosynthetic rate with the soil water content,and then calculate to get the optimum soil moisture condition for normal growth of Atriplex canescens seedings is 18%;(2)Atriplex canescens is a saline specie with strong salt resistance ability,with the increase of salt concentration,the plant height,ground diameter and biomass increment were increased first and then decreased.Compared with the control,the treatment of NaCl and Na2SO4 with salt concentration of 100-300 mmol·L-1 promoted the growth of seedlings to some extent,when the concentration of salt reaches 400 mmol·L-1,the growth of Atriplex canescens seedings has been inhibited to some extent,and the inhibition degree of NaCl was greater than Na2SO4;(3)Under NaCl and Na2SO4 two kinds of salt treatments,compared with the control,the net photosynthetic rate and chlorophyll content ofAtriplex canescens seedings showed a tendency to increase with the increase of salt concentration,in the concentration range of 100-400mmol·L-1,the higher the salt concentration,the stronger net photosynthetic rate and chlorophyll content,and the promotion degree of Na2So4 is greater than NaCl.While the transpiration rate and stomatal conductance oF Atriplex canescens seedings showed a tendency to increase first and then decreased,100-200 mmol·L-1 were significantly higher than the control,and the increase degree of NaCL was less than Na2SO4.When the concentration reached 300 or 400 mmol·L-1 was lower than the control,and the reduce degree of NaCl was less than Na2SO4.(4)Compared with the control,the proline,malondialdehyde,soluble sugar,soluble protein,SOD and POD activity of Atriplex canescens seedings were increased differently with the salt concentration increased under NaCl and Na2SO4 salt treatments.The increase in the range of 100-300 mmol·L-1 showed NaCl was greater than Na2SO4,That indicated the Atriplex canescens seedlings suffered more damage in the NaCl environment;(5)Applied regression analysis,get the optimum concentration range for Atriplex canescens seedings growth under NaCl treatment was 0-272.6mmol L'1,under Na2SO4 treatment was 0-272.6mmol·L-1,so the most optimum concentration range is larger of Atriplex canescens seedings growth normally in sulfate saline-alkali soil.