The phylogenetic origin of endangered species extinct in the wild is not always well understood, as a consequence of limited historical records of the original populations. Magnolia pseudokobus (Magnoliaceae) is one of only a few such woody plants in Japan. This triploid species was described in 1954 on Shikoku Island, but since then, no other individuals have been found in other locations. Currently, the only genet clonally propagated from the original tree can be seen in botanic gardens. In this study, we aimed to phylogenetically position M. pseudokobus by investigating genetic variations in the chloroplast genome, genome-wide SNPs, and microsatellites of focal and related species.

Phylogenetic trees based on the chloroplast genome and nuclear single nucleotide polymorphism (SNP) markers consistently showed that M. pseudokobus is well embedded within a clade consisting of M. kobus samples. Microsatellite analysis on a seedling of M. pseudokobus, which was cultivated adjacent to a M. kobus tree, showed that it was an interspecific hybrid. The genetic data suggest that M. pseudokobus was generated recently from M. kobus, allowing for the production of viable seedlings. Considering that the species is triploid and is not agamospermous, and any wild populations of M. kobus are not known from Shikoku Island, M. pseudokobus may be a ploidy variant of M. kobus, generated by spontaneous triploidization in M. kobus individual(s), which were possibly introduced by humans as ornamental tree(s). In conclusion, M. pseudokobus appears to be conspecific with M. kobus, and better recognized as M. kobus f. pseudokobus.

由于原始种群的历史记录有限，对在野生环境中灭绝的濒危物种的系统发生起源并不总是很了解。玉兰（Magnoliaceae）是日本仅有的少数几种木本植物之一。1954年在四国岛上描述了这种三倍体物种，但自那时以来，在其他位置未发现其他个体。目前，在植物园中只能看到从原始树无性繁殖的种系。在这项研究中，我们旨在通过调查叶绿体基因组，全基因组单核苷酸多态性以及局灶性和相关物种的微卫星中的遗传变异来系统地定位拟假单胞菌。

基于叶绿体基因组和核单核苷酸多态性（SNP）标记的系统发育树一致显示，假单胞菌很好地包埋在由M. kobus样品组成的进化枝中。上的幼苗微卫星分析M. pseudokobus，将其培养邻近M. kobus树，表明它是一个种间杂种。遗传数据表明，M. pseudokobus从最近生成M. kobus，允许生产可行的幼苗。考虑到该物种是三倍体的，并且不是无精子的，并且从四国岛的伪柯巴氏菌中不知道柯巴柯氏菌的任何野生种群。可能是kobus的倍性变异体，是通过kobus个体自发的三倍化产生的，可能是人类作为观赏树引入的。总之，假单胞菌似乎与kobus菌是同种的，并且更好地被认为是kobus f.。伪bus。