Dynamic of Gutta-percha Formation and Accumulation in Samara of Eucommia ulmoides

For better understanding the annual and year after year changes and regularities of gutta-percha content in samara of Eucommia ulmoides and for providing scientific theory for effective use of gutta-percha, studies were conducted in 2002 at the experimental demonstration base in Songxian County, Henan Province. Typical sample-tree selection and random selection were applied in this study. Integrated extraction was used to test the gutta-percha content rate. The results showed that gutta-percha content changes in samara could be divided into two stages. The content in kernel and pericarp performed a close relation with the growth of samara, which increased rapidly along with the samara's growth before the samara stopped to grow; while the content increased slowly after the samara's development. The gutta-percha content was in stable among the fruits from different ages of trees. Outstanding production increase was achieved through setting up orchards by grafting female branches on mature trees and by planting grafted saplings. Therefore, high-yield gutta-percha orchard could be established either by planting grafted saplings or by grafting female branches.