It is very important to confirm and understand the genetic background of cultivated plants used in multiple applications. The genetic background is the history of crossing between maternal and paternal plants to generate a cultivated plant. If the plant in question was generated from a simple origin and not complicated crossing, we can easily confirm the history using a phylogenetic tree based on molecular data. This study was conducted to trace the origin of “Tottori Fujita 1gou” and “Tottori Fujita 2gou”, which are registered as cultivars originating from Phedimus kamtschaticus. To investigate the phylogenetic position of these cultivars, the backbone tree of the genus Phedimus needed to be further constructed because it retains inarticulate phylogenetic relationships among the wild species. We performed molecular phylogenetic analysis for P. kamtschaticus, Phedimus takesimensis, Phedimus aizoon, and Phedimus middendorffianus, which are assumed as the species of origin for “Tottori Fujita 1gou” and “Tottori Fujita 2gou”. The molecular phylogenetic tree based on the internal transcribed spacer (ITS) and psbA-trnH sequences showed the monophyly of the genus Phedimus, with P. takesimensis forming a single clade. However, P. kamtschaticus and P. aizoon were scattered in the tree. It was verified that “Tottori Fujita 1gou” and “Tottori Fujita 2gou” were embedded in a clade with P. takesimensis and not P. kamtschaticus. Therefore, origination from P. takesimensis was strongly supported. Based on these results, molecular phylogenetic analysis is suggested as a powerful tool for clearly tracing the origin of cultivated plants.

Chrysanthemum zawadskii Herbich is widely distributed from northern Europe to East Asia. It has been reported that various ploidy levels ranging from diploid (2n = 2x = 18) to decaploid (2n = 10x = 90) are distributed in Korea. The diploid populations of C. zawadskii, however, have limited habitats, with only four populations from two locations compared to polyploids that are widely distributed in Korea. During recent biodiversity research on the C. zawadskii complex, new habitats of diploid populations of C. zawadskii not reported earlier in Korea were identified. To understand the speciation mechanism accompanying polyploidization of the C. zawadskii complex, it was necessary to investigate the features of these new populations as to whether they identical to or different from previously reported diploid populations. For this purpose, we identified the number and karyotypes of somatic chromosomes in four new diploid populations and compared the morphological features. It was found that the new diploid populations differed slightly in terms of the size and color of the flowers and in the shape of the leaves, with continuous variations. Representative karyotypes of the new populations were included in previously reported diploid karyotypes, but the numbers and locations of satellite chromosomes differed. In addition, we found that one of them is a sympatric population with different ploidy levels, including diploid, tetraploid, and hexaploid. From these results, it was confirmed that morphological and cytological variations exist among diploid populations in the C. zawadskii complex.