Studies on chemical constituents from twigs of Morus atropurpurea Effect of nitrogen and potassium combined application on mulberry (Morus atropurpurea Roxb.) leaf yield and quality,and silk cocoon quality Chemical constituents from root barks of Morus atropurpurea Chemical constituents in leaves of Morus atropurpurea and their α-glucosidase activity Pollen Morphology of Morus atropurpurea with Different Ploidies