Comparative Research On Effects Of Zn²⁺ And NA On Salt Toxicity Of Glycine Soja And Glycine Max

The Glycine soja populations BB52(the salt tolerant) and N23227(the salt sensitive),the Glycine max cultivar Lee68(the salt tolerant) were used as the experimental materials.After the selection of chloride channel inhibitors and the determination of their concentration,the ion absorption,ion toxicity and photosynthesis in seedlings were studied under salt stress with additional chloride channel inhibitors.The results are as follows:Zn²⁺and NA had no obvious influence on the seed germination.However,they showed different effects under NaCl stress.Absorption of Cl^-was inhibited by additional 20μmol·L^-1 Zn²⁺,the relative electrolytic leakage and MDA content were obviously decreased compared to the NaCl treatments.However,The content of chlorophyll was obviously increased.The effect of 20μmol·L^-1 Zn²⁺ was more obvious than that of 10μmol·L^-1 Zn²⁺.Plus additional 20μmol·L^-1 NA showed the reverse.During the treament of 150 mmol·L^-1 NaCl for 6 days,BB52 and Lee68 accumulated more Na⁺ and Cl^-in roots and stems in contrast to N23227,but the content of Na⁺ and Cl^-in leaves was lower than N23227.The content of Cl^-in roots, stems and leaves were decreased after plused additional 20μmol·L^-1 Zn²⁺,while the content of K⁺ was still maintained a higher level.The effects were reversed under additional 20μmol·L^-1 NA.After treament of 150 mmol·L^-1 NaCl for 6 days,the contents of K⁺ in seedlings, NO₃^-,chlorophyll and the osmotic potential in leaves of the three experimental materials were decreased compared to control,the contents of Cl^-,MDA and relative electrolytic leakage were obviously increased under NaCl stress.Under NaCl stress with additional 20μmol·L^-1 Zn²⁺,the contents of K⁺,NO₃^-,chlorophyll,and the osmotic potential were increased,the contents of Cl^-,MDA and relative electrolytic leakage were obviously decreased compared to the NaCl treatments.The NaCl stress with additional 20μmol·L^-1 NA showed the reverse.After treament of 150 mmol·L^-1 NaCl for 6 days,the content of chlorophyll,Pn (net photosynthetic rate);Ci(intercel lular CO₂ concentration);Gs(stomatal conductance);Tr(Transpiration rate) and Fv/Fm were obviously decreased compared to control,but Ls(stomatal limitation value) was increased.Under NaCl stress plus additional 20μmol·L^-1 Zn²⁺,most of the physiological indexes were increased obviously compared to the NaCl treatments except Ls.The NaCl stress with additional 20μmol·L^-1 NA showed the reverse.So it can be concluded that the additional 20μmol·L^-1 Zn²⁺ may alleviate the chloride/salt toxicity of soybean seedlings under NaCl stress.