Effects Of Salt Treatments On Characteristics Of Growth And Photosynthesis Of Lycium Ruthenicum Murr.

In order to improve the utilization efficiency of saline-alkali land in the Qaidam Basin,increase the economic benefits of the economic salt-tolerant plant Lycium Ruthenicum Murr.(LRM),and achieve the dual effects of improving the ecological environment and promoting local economic development.This paper studies the salt tolerance mechanism of LRM,to provide a theoretical basis for the introduction and domestication and the extensive planting of it.In this study,a pot experiment was conducted using annual LRM as a material to study the response of NaCl(NC),Na2SO4(NS)and NaHCO3(NH)(100 mmol·L-1,200 mmol·L-1,300 mmol·L-1,400 mmol·L-1 and 500 mmol·L-1)treatment on LRM.The characteristics of physiological and growth of LRM were measured and analyzed.The conclusions are as follows:(1)The three kinds of salt treatments of NC,NS and NH affected the characteristics of osmotic regulatory,photosynthetic and growth of LRM.The contents of membrane lipid peroxidation MDA were increased under salt treatment.In order to carry out normal growth under salt treatment,the contents of osmotic regulatory substances Pro,SS and SP in leaves were increased to produce an adaptive mechanism for salt treatment.LRM has a certain adaptive ability under 100 mmol·L-1 salt treatment,which can maintain the requirement of normal growth.(2)Salt stress reduced the chlorophyll content of the leaves of LRM,which had an effect on photosynthesis.When the salt concentration was 100 mmol·L-1,the Pn of LRM was larger than CK.The effect of salt treatment on Pn was changed from the stomatal limiting factor to the non-stomatal limiting factor in the salt concentration of 200-300 mmol·L-1.(3)The time point at which the maximum or minimum values of Fo,Fm and Fv/Fm appeared corresponded to Pn of LRM,at which occurred photoinhibition or midday depression of photosynthesis.The higher the salt concentration,the smaller the minimum values of Fv/Fm,and the lower the utilization efficiency of light energy of LRM.LRM had certain adaptability to the salt treatment environment after 15 days of salt treatment.The transfer process of photosynthetic electron QA to QB under 100 mmol·L-1 treatment did not hinder,but with the increase of salt concentration,the electron transport capacity of PSII reaction center,thylakoid membrane and electron donor side of LRMboth the receptor and the receptor side were affected to varying degrees.(4)The changes of salt treatment on the physiology and photosynthetic characteristics of LRM affected the height and biomass.The NCI and NS1 did not significantly affect the AH of LRM.The growth characteristics of NC2 and NS2 treatment showed hysteresis.Salt treatment began to have a significant effect on the growth of between 200 and 300 mmol·L-1.The alkaline salt NH inhibits the growth of black carp seedlings more than the neutral salt NC and NS.Because the higher pH value in alkaline salt inhibited the growth and absorption capacity of root,it has an effect on the physiological and photosynthetic characteristics of LRM.In conclusion,the salt treatment with 100 mmol L-1 will not have a significant effect on LRM.The salt tolerance threshold of LRM is between 200-300 mmol·L-1.The inhibition of alkaline salt NH on LRM is greater than that of neutral salt NC and NS.