which type of plants show successful grafting & why it is so?

The portion of a plant that is grafted on the other plant is called scion, and the plant in which grafting is performed is called stock. Grafting is used to improve variety of plants such as sugarcane, mango, apple, etc.

 For succesful grafting,  proper vascular connection is necassary.  Grafting is easy to be performed in dicots as compared to monocots such as oak.