The distribution of wild apple germplasm in Northwest China and its potential application for apple rootstock breeding.

摘要

China is one of the major germplasm centers of Malus species and is the origin of more than 25 species. Northwest China includes the three provinces of Shaanxi, Gansu and Qinghai and the two autonomous regions of Ningxia Huis and Xinjiang Uighur. It contains an unusually high diversity of wild apple germplasm resources comprising 16 Malus species. The species and ecotypes in the Qinling Mountains are richest, accounting for 80% of those in the Northwest China (65% of those of all China). Among the 16 species, the ecotypes of are most abundant and they are mainly found in humid conditions. M. sieversii is mostly distributed in the valleys of the Tianshan Mountains with its central distribution area being the counties of Yili, Gongliu and Xinyuan in Xinjiang, covering 14,000 ha. The wild Malus species of China are differentiated and adapted to local climates. Chinese wild Malus has been used for rootstocks for a long time in China. Among them, the seedlings of are widely used for rootstocks. However, it is important to make an additional effort to incorporate the desirable genes of this germplasm into dwarfing apple rootstocks.