Four new Eucommia ulmoides triploid cultivars, “Jingzhong No. 1”, “Jingzhong No. 2”, “Jingzhong No. 3” and “Jingzhong No. 4”, developed by Professor Kang Xiangyang’s research team from Beijing Advanced Innovation Center for Tree Breeding by Molecular Design of Beijing Forestry University, have been recently granted Right Certificate for New Varieties of Plants by the State Forestry Administration. Together with “Jingzhong No. 5”, “Jingzhong No. 6”, “Jingzhong No. 7” and “Jingzhong No. 8” authorized in 2018, eight triploid cultivars of Eucommia ulmoides have received the national certificates. Dr. Li Yun, a postdoctoral researcher of the Innovation Center, is the leading breeder of these new varieties.
The eight new Eucommia ulmoides triploid cultivars are characterized by fast growth, large leaves, and massive content of secondary metabolites such as medicinal components. Compared with those diploid counterparts, they grow 30% faster in average height and stem diameter, their mean leaf area and leaf thickness exceed those of the diploids by 45% and 30% respectively, and they contain aucubin, chlorogenic acid, geniposide and geniposidic acid 1.5~2.0 times the amount of the diploids. Plantation of the eight new triploid cultivars of Eucommia ulmoides can significantly increase the yield of leaves, gum and drug ingredients to effectively reduce the cost of raw materials for production. It can also provide excellent materials for emerging gum industry, pharmacy, and feed additive industry chain, and serve as a new energy force driving the adjustment of national industrial structure.
Significant difference in growth and morphology between diploid Eucommia ulmoides (left) and triploid Eucommia ulmoides “Jingzhong No.1” (right)
Eucommia ulmoides is dioecious and also the single species in the Eucommia genus in the Eucommiaceae family, thus with limited crossbreeding effect. Professor Kang Xiangyang’s research team has created a new way to solve the technical problems of chromosome doubling in Eucommia ulmoides gametes by focusing on the development and utilization goals of Eucommia ulmoides in industries such as gum and pharmaceutical production, and relying on relevant studies financed by the National Natural Science Foundation of China. A batch of Eucommia ulmoides triploid (2n=3x=51) new germplasm have been obtained for the first time in the world by the team and it has then selected and bred 8 new triploid cultivars of Eucommia ulmoidesincluding “Jingzhong No. 1”. The dream of Eucommia ulmoides breeders for 30 years has been eventually fulfilled.
The research team suggests that the application of new triploid cultivars such as “Jingzhong No. 1” adopt the production mode of “seedling forest” cultivation, mechanized harvesting and whole-plant utilization. The specific process goes as follows: row compact planting cultivation of strip forest; mechanized flat stubble harvesting; mechanized debarking and defoliation, high temperature drying and de-enzyming, and mechanized kneading to separate leaf vein and mesophyll; comprehensive utilization by location: leaf vein and bark for gum, leaf meat for medicine or feed additives, and stem for scrimber. This process helps achieve the goal “one raw material, multiple benefits”, thus promoting the development of Eucommia ulmoides industry.
Relevant data show that Eucommia ulmoides (Eucommia ulmoides Oliv.) is a multi-purpose economic tree species characteristic of China. Its bark and leaves function as medicine and the leaf is rich in more than 70 active ingredients including chlorogenic acid, pinoresinol diglucoside, geniposidic acid and aucubin. It provides excellent raw material for the development of modern traditional Chinese medicine, health care products and functional food, as well as the best feed substitute after the 2020 national ban on adding antibiotics to feed. Besides, it is a tree species with great potential for gum utilization in temperate zone in China. The bark, peel and vein are high in gutta-percha, which is used for the development of new functional materials with such properties as thermoplasticity, thermoelasticity, low temperature plasticity, tear resistance, wear resistance, corrosion protection, radar wave penetrability, energy absorption and shock absorption, and shape memory. These materials can be widely used in automobile manufacturing, shipbuilding, high-speed railway, communication, medicine, electric power, food, water conservancy, construction, sports and other fields. (A19)