外源精胺和亚精胺对盐胁迫下2种小麦幼苗生理特性的影响OA

To investigate the effects of exogenous spermine(Spm)and spermidine(Spd)on the growth and salt toler-ance of wheat seedlings,this experiment used two wheat varieties with different salt tolerances(Bainong 201,with strong salt tolerance;Aikang 58,with weak salt tolerance)as materials.It explored the regulatory effects of seed soaking with three con-centrations(0.05 mmol/L,0.10 mmol/L,and 0.20 mmol/L)of Spm and Spd on the growth parameters(germination rate,root length and shoot length)and physiological indicators including chlorophyll(Chl.)content,malondialdehyde(MDA)content,proline(Pro)content and peroxidase(POD)activity of wheat seedlings under different degrees(25 mmol/L NaCl,50 mmol/L NaCl,and 100 mmol/L)of NaCl stress.The results showed that,compared with the control(cultivation in distilled water),NaCl stress signifi-cantly inhibited wheat seed germination and seedling growth.The germination rate,root length,shoot length,chlorophyll content of Bainong 201 and Aikang 58 decreased significantly as the salt stress concentration increased,while the MDA content,Pro content,and POD activity increased sig-nificantly.Seed soaking with appropriate concentrations of Spm and Spd alleviated the inhibitory effects of salt stress on seed germination rate,root length,shoot length,and chlorophyll content in both Bainong 201 and Aikang 58.This treatment resul-ted in a decrease in MDA content and a further increase in Pro content and POD activity.Based on a comprehensive analysis using the membership function method,the results indicated that Spd was more effective than Spm in alleviating the toxic effects of salt stress on seedlings.Furthermore,its positive effect was more pronounced in the salt-sensitive variety Aikang 58 than in the salt-tolerant variety Bainong 201.Among the treatments,seed soaking with 0.10 mmol/L Spd demonstrated the best efficacy in mitigating NaCl stress-induced damage to wheat seedlings.