Crossability between Transgenic Blue Chrysanthemums and the Wild Chrysanthemum Species <i>Chrysanthemum japonense</i> var. <i>japonense</i>

Abstract

Transgenic chrysanthemums (Chrysanthemum morifolium) with blue flower colors have already been created, and are expected to be commercialized. However, cultivated chrysanthemums are known to cross with wild species native to Japan, and careful studies are needed to assess the risk of these transgenes escaping into wild Chrysanthemum populations. We previously reported on the transmission of transgenes from the model cultivar 'Taihei' to interspecific progeny. For this study, we used the recently developed cultivar 'Sei Arabella' and a promising breeding strain (T37) as transgene hosts, and performed crosses between these lines and the wild species Chrysanthemum japonense var. japonense. We found relatively high seed set rates (20.6%-83.4%) after artificial, reciprocal pollinations, and the inheritance and segregation of the transgenes in the hybrid progeny were confirmed by PCR. Some of the transgenic progeny exhibited blue flower colors and contained modified anthocyanins, like their transgenic parents. These results were similar to those obtained with 'Taihei' and thus suggested that the risk of transgenes escaping to wild species could be quite high. Therefore, it will be important to investigate techniques to reduce this risk.

Excision of DNA fragments with the <i>piggyBac</i> system in <i>Chrysanthemum morifolium</i>

“…Several interesting transgenic C. morifolium have been developed, with traits such as insect resistance (Shinoyama et al 2002) and naturally impossible violet and blue flower colors (Noda et al 2013(Noda et al , 2017. For the commercial use of transgenic C. morifolium, it is legally necessary to confer sterility to these plants to avoid gene transfer in the area where it can pollinate wild species (Aida et al 2018(Aida et al , 2020. Genome editing is one of the potential methods to systematically modify traits, such as sterility.…”