An overview of Populus genetic resources in southwest China

Abstract

There are abundant genetic resources of Populus in southwest China, which play an important role in scientific research and practical application. These resources are unfamiliar to the rest of the world and their value has not been widely appreciated; hence the purpose of this paper is to present the resources to the world, and to encourage more attention to be paid to them. There are 28 species, 20 varieties, and about 10 natural hybrids of Populus in the region. Of the 28 species, 25 are endemic to China, and 18 of them are indigenous to southwest China. So the region is regarded as one of the nat-ural distribution and variation centres for Populus in China. The species fall into three floristic types: China-Japan, China-Himalayas, and ancient tropical; and show an obvious zonation in horizontal and vertical distribution with excellent adaptability to a wide range of environments. At present, only a few species are generally recognized, and to some extent grown and utilized, while most of them are still in natural conditions but face severe threat. It is therefore urgent to recognize, conserve and utilize these significant poplar resources.