Effects of Water Deficiency on the Activities of Key Enzymes Involved in the Starch Synthesis and the Accumulation of Starch for the Transgenic Rice Plants Carrying Antisense Wx gene during Grain Filling Some technical problems in studies on DNA markers of Chinese materia medica Ⅱ Discussing on RAPD technology and methodology Study on the Dynamic Changes of the Major Carbohydrate Content and the Related Enzyme Activities during the Microcorm Development of Colocasia esculenta