Effects of Plant Growth Regulator on Cutting Propagation of Rhododendron latoucheae Effects of Drought Stress on Seed Germination and Seedling Physiological Characteristics of Rhododendron latoucheae Influences of Growth Media, and Hormone Types and Concentrations on Cutting Propagation of Rhododendron latoucheae Effects of hormone types and concentrations on cutting propagation of Rhododendron latoucheae and its evaluation