Significance With the establishment of the China National Botanical Garden in Beijing and the South China National Botanical Garden in Guangzhou, the construction of China national botanical garden system has entered a stage of substantial progression, and is steadily advancing in accordance with the principle of "establishment upon maturity". Based on the comprehensive consideration of such factors as major national strategies, characteristics of major climate types and typical vegetation regionalization, biodiversity hotspots, and needs of economic and social development, the Yili-Turpan National Botanical Garden has been included in the layout of China national botanical garden system. With unique regional and biodiversity characteristics, the Yili-Turpan National Botanical Garden is the only botanical garden in the temperate continental climate, and a treasure house for the collection, introduction and conservation of arid eremophytes. Arid areas constitute about one third of the Earth's terrestrial surface. As the only national botanical garden located in arid areas in China, the Yili-Turpan National Botanical Garden possesses unique plant diversity by incorporating many endemic species, including wild relatives of key crop plants and ancestor species of economic fruit trees. The conservation of plant biodiversity and the sustainable utilization of plant germplasm resources have gained more attention from parties to the Conference on Biological Diversity and local governments. However, due to extensive agriculture, unsustainable use and global climate change, biodiversity loss in arid areas has caused disproportionate impact on the ecosystem mainly as a result of low redundancy and high risk of trophic cascades in recent decades. Extensive collection and conservation of wild plant germplasm resources in arid areas and effective ex situ conservation are of great significance for the security of global biological resources.

Progress It is planned to integrate Yili Botanical Garden and Turpan Eremophytes Botanical Garden, both established in Xinjiang by Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences (CAS), into Yili-Turpan National Botanical Garden, a new national botanical garden that is proposed to be incorporated into the national botanical garden system. Turpan Eremophytes Botanical Garden and Yili Botanical Garden are highly complementary in terms of species conservation. By implementing ex situ conservation in the two botanical gardens, the full coverage of eremophytes conservation in Northwest China can be achieved, and more temperate eremophytes germplasm resources can be collected and preserved, so that the protection of temperate eremophytes germplasm resources can be more effective, extensive and scientific, which is of far-reaching significance for the construction and scientific layout of China national botanical garden system. The goal of Yili-Turpan National Botanical Garden is to construct an ex situ conservation system for plants in arid areas, build a new germplasm bank covering arid areas in Central Asia, Africa and Northwestern China, and build the world's largest comprehensive botanical garden in arid areas that integrates such functions as ecological protection, species conservation, scientific research, development and utilization, experimental demonstration, science popularization and education, and tourism. In the first phase, an alpine forest vegetation conservation area, 10 species conservation exhibition areas, 4 unique economic plant collection conservation areas, 5 experimental demonstration areas for plant resources development and utilization, 5 eremophytes conservation exhibition areas and river wetland landscape exhibition area are planned for construction, with more than 10, 000 plant species (varieties) to be collected and preserved. In addition, a germplasm resource bank of plants in arid areas is to be established to facilitate the implementation of scientific research on conservation of biodiversity, preservation and sustainable utilization of plant resources such as ornamental medicinal aromas, breeding of important forest fruit resources, and development and utilization of sand control plant resources in arid areas. Moreover, it is planned to actively promote the expansion and extension of science popularization, by setting up a comprehensive science popularization service system, and organically combining general science popularization with in-depth science popularization.

Conclusions and Prospects Yili-Turpan National Botanical Garden will, according to the overall construction arrangement of China national botanical garden system, build an ex situ conservation system for plants in arid areas based on enhanced coordination and joint efforts. It will also strengthen scientific and technological support to promote the application of relevant achievements in China, and deepen international exchanges to contribute to the building of the world's largest comprehensive botanical garden in arid areas that integrates such functions as ecological protection, species conservation, scientific research, development and utilization, experimental demonstration, science popularization and education, and tourism. In the future, Yili-Turpan National Botanical Garden should fulfill the historical mission of ex situ conservation and scientific research of wild plant resources in arid areas to lay a solid foundation for achieving China's biodiversity conservation goals and building a beautiful China, and should help materialize president Xijinping's requirement of the role of "core area of the Silk Road Economic Belt" to better provide scientific and technological support and Chinese solutions for the implementation of the "Belt & Road" initiative and the construction of a community with shared future for mankind.