| Eucommia ulmoides Oliv is the Chinese native valuable non-timber species, which is planted in 26 provinces from sub-tropic zones to worm-temperate zones in China. The bark of Eucommia ulmoides Oliv is a unique eximious herbal medicine and an important material for exporting of China. It is in the first category of Chinese herbal medicine, which can make physique muscular, benefit for liver as well as for kidney, and prevent from aging after long time taking. With straight trunk, beautiful shape of the tree, developing root system, fast growing, strong resistances, few plant diseases and insect pests, Eucommia ulmoides Oliv is a special outstanding non-timber species in hill mountainous areas and plains. It is also the most adaptable gutta-percha source tree around the world. Eucommia's pericarp, bark and leaf contain gutta-percha, which are the precious natural rubber resources in China. Furthermore, the unique function of duality of "plasticity and elasticity" and shape memory of gutta-percha high-elastomer makes it a quite foreground for industrializations.Previous studies have been given priorities to cultivations aimed at yielding both timber and bark due to the medicinal purpose of barks. Researches on nurse and utilization were mainly encircling bark yield. Active components in leaves were also under studied. There is no thorough report so far on gutta-percha in samara, bark and leaf.New ideas was put forward in this paper of running Eucommia orchard and horticulture as well as industrialization aimed at main problems in existence of producing and utilizing the tree. This study was supported by national key project "Selection and optimization cultivation of new Eucommia ulmoides Oliv clones of high-content of gutta-percha", national high-tech project "Rapid propagation and high yield cultivation technology of Eucommia ulmoides Oliv", national forestry administration project "Nurse technology for high yield gutta-percha of Eucommia ulmoides Oliv" and key project of Henan province "Integrated cultivation technology to enhance gutta-percha yield of Eucommia ulmoides Oliv ", etc.For the first time, years' of systematic studies were conducted in this paper on accumulation dynamic of gutta-percha formation, heredity diversity and selection of high yield gutta-percha clones. The regularities of gutta-percha development and its accumulation dynamic in wherever the organs like samara bark and leaf, provided theoretical foundations for utilizing Eucommia recourses reasonably and effectively as well as for developing high yield gutta-percha technology. Heredity diversity of Eucommia ulmoides was under studied by the properties of samara, bark and leaf; character of colony inherit variance was explored through investigating the variances character of gutta-percha inherit from different production areas and different clones; meanwhile, individual heredity diversity was opened out by comparison of inherit laws among different clones. The optimal approach and model for utilization and development of gutta-percha was put forward under the systematic studies on gutta-percha formation process in Eucommia trees and its heredity diversities. High yield gutta-percha clones was thus selected by means of determination and statistic analysis of fructification and growth characters among different clones, which provided superior clones for high yield gutta-percha and theoretical guidance for mass uses and scientific research on Eucommia in China.The annual accumulation of gutta-percha in samara could be divided into two stages. The change of gutta-percha content in pericarp and samara correlated closely along with the growth of samara before the samara stopped to grow. Gutta-percha content in pericarp and samara increased rapidly along withthe samara growth and continuously formed and accumulated but slower after the samara stopped to grow. Annual change curve of gutta-percha in both pericarp and samara was stable and so did the gutta-percha content among trees with different ages. Distinct production increase was obtaine... |
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