The Effect of Neutral Salt and Alkaline Stress with the Same Na+ Concentration on Root Growth of Soybean (Glycine max (L.) Merr.) Seedlings

Salt stress is a common abiotic that negatively affects crop growth and yield. However, there have been significant differences found on the effect degree management mechanism in plants under neutral salt alkaline stress. In this study, two soybean cultivars, Heihe 49 (HH49, saline-alkali tolerant) Henong 95 (HN95, sensitive), were hydroponically cultured treated with solutions of 25, 50, 75 mM Na+ form NaCl, Na2SO4, NaHCO3, Na2CO3. Plants (NaHCO3 Na2CO3) showed greater decrease root activity both cultivar seedlings than stresses (NaCl Na2SO4) 25–75 concentration. Alkaline (25–50 content) activated higher ability antioxidant defense (by enhancing activists superoxide dismutase (SOD), peroxidase (POD), ascorbate (APX)) increased content soluble sugars to level stresses. treatments reduced enzyme activities osmotic regulating substance content. Furthermore, was able induce DNA damage cell cycle arrest HH49 HN95 seedling roots. Treatment Na2CO3 induced least random amplification polymorphic (RAPD) polymorphism roots among all treatments, which could related early arrest.