Collection, conservation and propagation techniques of the old elm (Ulmus pumila) tree resources in Ke'erqin sand land.
Xu Jiuru;Cheng Shiming;Zou Shouyi;Zhang Weidong;Zhu Xinyun;HanYusheng.College of Biology, Beijing For. Univ.,100083,P. R. China.\;
It was found by the investigation in our research project that only about 30 elm trees aged more than 100 years remain in the Ke'erqin sand land which covers more than 10 million hectares. In this region, the main plant community is grassland with sparsed elm. To preserve these precious and excellent gene resources which have been endured long period of nature selection and have the capacity to adapt to adverse environment, a largest elm gene bank in China is being built. The main task of the gene bank is to collect and preserve the old elm trees in the region of Ke'erqin. Simultaneously, some representative elm genus, varieties and types which are adapted to the region have been collected. By the end of the year 2 000, the gene bank had collected 88 kinds of germplasm resources. It is anticipated that the area of the gene bank would reach 7 hectares and 100 kinds of germplasm resources would be collected by the end of 2002 when the gene bank be completely built. In order to permanently utilize these gene resources, two kinds of expanding propagation technique\|cutting and grafting were studied .