As a wild apple species native to central Asia, Malus sieversii (Ledeb.) Roem. is distributed in a wide region covering most of the Tienshan Mountains. Malus sieversii is a useful genetic pool for apple breeding since rich with diversity. In this paper, we first describe the species range of this endangered species. We then describe an in situ reserve that has been established. We also investigated some reproductive characteristics of M. sieversii including pollen germination, seed dormancy, and seed viability. Both stratification and seedcoat removal efficiently released seed dormancy and accelerated seed germination. Pollen germination rate is around 60%. Our data suggest that injurious insects and human activities, rather than reproductive characters, limit the renewal of M. sieversii.
Meiling Yang, Fang Li, Hong Long, Weiwei Yu, Xiuna Yan, Bin Liu, Yunxiu Zhang, Guorong Yan and Wenqin Song
Qing Shen, Hua Bian, Hai-yan Wei, Li Liao, Zhi-yong Wang, Xiao-yan Luo, Xi-peng Ding, Zhenbang Chen and Paul Raymer
analysis. Based on the genetic resemblance matrix, the PCA was conducted on 58 P. vaginatum accessions and four cultivars to further understand the ecological distribution of different accessions. Figure 3 presents the distribution of the different
Rebecca M. Harbut, J. Alan Sullivan, John T.A. Proctor and Harry J. Swartz
diverse ecological distribution of the Fragaria species ( Darrow, 1966 ) and the ecological differentiation within species that has been observed in previous studies ( Hancock and Bringhurst, 1978 ) may be exploited to develop strawberry genotypes with a
Kevin Fort, Joaquin Fraga, Daniele Grossi and M. Andrew Walker
the faster leaf and root growth rates of the mesophyte Quercus marilandica to selection that maximized resource uptake in a resource-rich soil, but at the cost of reduced stress tolerance, sufficient to contribute to a differential ecological