Abstract
Malus sieversii (Ledeb.) M. Roem. is recognized as the ancestor of the cultivated apple tree. It has a valuable gene pool, and in the last decades, it becomes endangered in Kazakhstan. The genetic diversity of 13 clone-varieties of Sievers apple tree (Malus sieversii) of Dzungarian population from the introduction collection of the Main Botanical Garden in Almaty (Kazakhstan) and 31 samples from three natural populations were assessed using eight polymorphic ISSR markers. The phylogenetic relationship of the clone-varieties with the natural population was estimated using ribosomal (ITS) and chloroplast DNA (rps16 intron, trnL intron, trn L-trn F). The data revealed a high genetic diversity of various clones and samples of Sievers apple tree of the Dzungarian populations. As a result of phylogenetic and cluster analysis the studied clones and samples of M. sieversii from natural populations formed a cluster, samples of supposedly hybrid origin formed 2 clusters, and no clustering was detected depending on geographical distance. The data demonstrate that there is an active information exchange between the populations.