A Genetic Linkage Map Of Wild Chrysanthemum Species Indigenous To Korea And Its Challenges

Chrysanthemum is widely used as an ornamental plant because it has tremendously diverse in morphologies including flower shapes, sizes, colors and plant architecture. However, genetic study on this crop is not intensively performed and many of genetic features are not known yet. Although several linkage maps of Chrysanthemum based on a variety of molecular markers were developed, all of them used Chrysanthemum cultivars which are mostly hexaploids. In the current study, we present a linkage map of an F1 population crossed between two parents, C. boreale (2n = 2x = 18) and C. indicum (2n = 2x = 18), which are wild Chrysanthemum species collected in South Korea. Forty-eight linkage groups were formed but a few linkage groups had clustered markers which are very tightly linked. Thus, cytogenetic analysis was performed to explain this phenomenon. As a result, chromosomal rearrangements including reciprocal translocation seems to be involved in the two parents used in the current study. We discuss what these chromosomal rearrangements cause to construct genetic linkage maps. We also suggest possible solutions to improve the quality of this linkage map in the near future. The results in the current study suggest that it needs to be very cautious to choose species for breeding in Chrysanthemum. (C) 2018 Friends Science Publishers