不同类型盐胁迫对春小麦种子萌发及幼苗生长的影响OA

To clarify the effects of different types of salt stress on seed germination and seedling growth of spring wheat,this study used two main spring wheat varieties(Yongliang 4 and Nongmai 2)cultivated in the Hetao Irrigation District of Inner Mongolia as experimental materials.Three types of salt stress(neutral salt,alkaline salt,and composite salt)were applied at different concentration gradients.Seed germination characteristics,seedling growth,and biomass accumulation were measured.The salt tolerance threshold and limiting concentra-tion value for each index were calculated.The salt damage grades of different varieties were evaluated,and redundancy analysis of stress ions as well as the construction and analysis of a partial least squares structural equation model were performed.The results showed that different types of salt stress had varying degrees of inhibitory effects on seed germination and seedling growth of the two wheat varieties.The inhibition intensity ranked as follows:alkaline salt stress(Na2CO3,NaHCO3)＞composite salt stress(NaCl,Na2SO4,Na2CO3,and NaHCO3)＞neutral salt stress(NaCl and Na2SO4).The effects of different salt stress ions were ranked as:cations(Na+)＞alkaline anions(CO32-,HCO3)＞neutral anions(SO4,Cl).Different spring wheat varieties also exhibited different responses to various types of salt stress.Under neutral salt stress and alkaline salt stress,there were no significant differences between Nongmai 2 and Yongliang 4 in terms of the mean values of salt tolerance threshold and limiting concentration(P＞0.05).Under composite salt stress,significant differences were observed between the two varieties(P＜0.05).In addition,there were significant differences in the effects of seed germination performance of the two varieties on the aboveground traits of seedlings(P＜0.05).Overall,Nongmai 2 exhibited stronger tolerance to various types of salt stress than Yongliang 4 from seed germination to the seedling stage.The above findings provide an important reference for the research on the mechanism of salt tolerance in spring wheat and the selection and breeding of new salt-tolerant varieties.