Differences of Growth and Development Characteristics of Different Tolerance Soybean Strains to Low-potassium Stress

Two soybean strains,T40 tolerant to low-potassium and GD8521 sensitive to low-potassium,were used to study the differences of growth and development characteristics in pot experiment under low and normal potassium treatments.Under low K treatment stress,the flowering stage of T40 was longer than under normal K treatment.Stem diameter and the number of branches reduced by 11.4% and 14.38%,respectively.However,the nodes of main stem increased by 16.12%.The stem dry weight reduced by 32.71% at branching stage.At podding stage,plant dry weight,leaf dry weight and stem dry weigh reduced by 8.75%,5.56% and 2.65%,respectively.The Plant dry weight,grain weight per plant reduced by 3.74% and 9.85% at maturity stage,while stem and pod husk dry weight increased by 0.68%.The pods per plant increased by 9.13%,while seeds per plant reduced by 1.93%.The results also showed that low-K stress made the flowering stage of GD8521 shorten.The Stem diameter and the number of branches reduced by 27.5% and 47.63 %,while the nodes of main stem increased by 21.84%.The stem dry weight reduced by 40.81% at branching stage.Plant dry weight,leaf dry weight and stem dry weigh reduced by 35.37%,26.53%,and 37.89% at podding stage,respectively.The plant dry weight,grain weight per plant and stem and pod husk dry weight reduced by 38.58%,40.99% and 36.71% at maturity stage,respectively.The pods per plant and seeds per plant reduced by 23.55% and 26.01%,respectively.T40 showed higher stability for growth and development characteristics and had more tolerance to low-K stress than GD8521.