羊草和披碱草盐碱胁迫生理响应比较研究OA

This study established gradient stress treatments of pH,NaCl,NaHCO₃,and Na₂CO₃ to compare the stress tolerance differences between Leymus chinensis and Elymus dahuricus.Evaluated parameters included growth indices such as seedling leaf length,root length,and fresh weight,as well as physiological indicators including chlorophyll content,relative electrical conductivity,malondialdehyde(MDA)content,superoxide anion(O-2·)content,antioxidant capacity,and osmoregulatory substance levels in mature leaves.A comprehen-sive evaluation was conducted using principal component analysis(PCA)in conjunction with the membership function value(MFV)method.The results demonstrated that alkaline salts(NaHCO3,Na2CO3)exhibited sig-nificantly stronger inhibitory effects compared to neutral salt(NaCl)and high pH conditions.With increasing Na⁺concentration and pH levels,the growth inhibition of L.chinensis was less pronounced than E.dahuricus.Addi-tionally,L.chinensis exhibited a smaller reduction in chlorophyll content,lower increase in relative electrical con-ductivity and malondialdehyde(MDA)levels,less accumulation of superoxide anion radicals(O-2·),and stron-ger antioxidant capacity compared to E.dahuricus.Additionally,L.chinensis accumulated higher levels of osmo-regulation substances(soluble sugars,soluble proteins,proline).The PCA-MFV comprehensive evaluation con-firmed consistent conclusions between seedling phenotype and mature plant physiological indices,demonstrating that L.chinensis possessed significantly superior comprehensive saline-alkali tolerance compared to E.dahuricus.This research provides a theoretical foundation for vegetation selection and breeding in saline-alkali soil.