The Comparative Study Of Salt Tolerance Of Rhus Chinensis Mill. And R.Taisanensis S.B.Liang

With the aggravation of global warming,the problem of soil salinization is becoming more and more serious.A large area of salinized land has been abandoned,which has become an ecological environment problem facing the whole world and seriously restricted the development of global economy.How to improve,develop and utilize salinized land has become an important problem in the field of agriculture.Breeding salt tolerant plants and studying the mechanism of salt tolerance are one of the effective ways to improve soil salinization.Therefore,Rhus chinensis Mill and R.taisanensis S.B.Liang seedlings were treated with different concentrations of NaCl(CK,100mmol/L,200mmol/L,300mmol/L)and different salt stress times(1d,5d,10d).The morphological changes and physiological responses of the two species of Rhus in salt stress were compared,and their salt tolerance was evaluated comprehensively by membership function and other methods.In order to select salt tolerant germplasm and provide theoretical basis for afforestation and afforestation in saline alkali land.The main results are as follows:1.The effects of salt stress on the apparent damage of the leaves of two species of Rhus :When the concentration of NaCl was less than 200 mmol/L,the apparent damage of the leaves of the two species was not obvious compared with the control;when the salt concentration was higher than 200 mmol/L or the stress time was longer than 5 days,the leaf damage of the two species was significantly aggravated.Under the same treatment,the damage degree of leaf curl,rust spot and dry phenomenon of Rhus chinensis Mill was significantly higher than that of R.taisanensis S.B.Liang.2.The effects of salt stress on photosynthetic parameters of two species of Rhus : under the same stress time,the net photosynthetic rate,stomatal conductance and transpiration rateof the two species of Rhus chinensis seedlings decreased with the increase of salt concentration,the intercellular carbon dioxide concentration of Rhus chinensis Mill seedlings increased first and then decreased,and the intercellular carbon dioxide concentration of R.taisanensis S.B.Liang seedlings increased continuously Under the same salt concentration,with the increase of salt stress time,the net photosynthetic rate,stomatal conductance and transpiration rate decreased,while the intercellular carbon dioxide concentration increased.R.taisanensis S.B.Liang has stronger photosynthetic capacity under salt stress.3.The effects of salt stress on the physiological indexes of two species of Rhus : under the same stress time,the chlorophyll content of the two species of Rhus seedlings showed a continuous downward trend with the increase of salt concentration,the contents of various antioxidant enzymes(SOD,cat,APX)and soluble protein first increased and then decreased with the increase of salt concentration,and the POD and MDA continued to increase with the increase of salt concentration;under the same salt concentration treatment,The increase of stress time will make MDA content continue to increase,and to a certain extent,enhance the activities of various enzymes and osmoregulants.The physiological indexes of R.taisanensis S.B.Liang are active and show stronger tolerance.4.Comprehensive evaluation of salt tolerance: the salt tolerance of Rhus chinensis Mill and R.taisanensis S.B.Liang seedlings was evaluated by membership function calculation,correlation analysis and principal component analysis.The results showed that: the comprehensive evaluation of salt tolerance of R.taisanensis S.B.Liang was higher than that of Rhus chinensis Mill,and had stronger salt tolerance.