不同苜蓿品种萌发期和苗期耐盐性评价OA

To investigate the effects of NaCl treatment on the growth and physiological characteristics of different al-falfa varieties during germination and seedling stages,this study utilized five varieties(Banongke No.1,Aohan,Zhongmu No.3,Zhongtian No.3,and Zangmu No.1)as experimental materials.During the germination stage,treat-ments included 0%(control),0.4%,0.8%,and 1.2%NaCl,with growth indices measured accordingly.At the seedling stage,growth performance under 0%(control),0.4%,and 0.8%NaCl treatments was evaluated,and changes in antioxi-dant enzyme activities,osmoregulatory substances,and Na⁺/K⁺accumulation were analyzed.The results indicated that during germination stage,as NaCl concentration increased,germination rate,germination potential,vigor index,root length,shoot length,and fresh seedling weight of all five varieties declined.The 0.8%NaCl treatment significantly in-hibited seed germination and growth across all cultivars,with Banongke No.1 exhibiting the highest germination poten-tial,showing a statistically significant difference(P<0.05)compared to the other four varieties.The 1.2%NaCl treat-ment severely suppressed germination,reducing the germination rate of Zhongtian No.3 to nearly zero.At the seedling stage,increasing NaCl concentrations inhibited the growth of all alfalfa varieties.However,Banongke No.1 showed a significant increase in root biomass compared to control under elevated NaCl levels,with a marked difference(P<0.05)from the other four varieties at 0.8%NaCl treatments.Na⁺content in leaves,stems,and roots generally increased with the increase of NaCl concentration for all alfalfa,showing significant differences from control(P<0.05).Under 0.8%NaCl treatment,Banongke No.1 displayed the smallest increments in Na⁺content in leaves and stems compared to con-trol,with values of 30.84 mmol/g and 40.5 mmol/g,respectively.With rising NaCl concentrations,K⁺content in stems and roots,as well as the K⁺/Na⁺ratio in stems,roots and leaves of all alfalfa generally decreased.With rising NaCl con-centrations,malondialdehyde content initially increased and then declined,soluble protein content decreased progres-sively,while proline content,superoxide dismutase,peroxidase,and catalase activities all increased,showing signifi-cant differences from control(P<0.05)under 0.8%NaCl treatment.Based on a comprehensive salt tolerance evalua-tion,the ranking of salt tolerance during germination stage was Banongke No.1>Zhongmu No.3>Zangmu No.1>Aohan>Zhongtian No.3;and at the seedling stage,the order was Banongke No.1>Zhongmu No.3>Zhongtian No.3>Zangmu No.1>Aohan.These results indicate that Banongke No.1 exhibits stronger salt tolerance than Zhongmu No.3,Zangmu No.1 surpasses Aohan in salt tolerance,and Zhongtian No.3 demonstrates greater sensitivity to NaCl during germina-tion stage than at the seedling stage.