The auxins centrophenoxine and 2,4-D differ in their effects on non-directly induced chromosome doubling in anther culture of wheat (T-aestivum L.)

Doubled haploid technologies have become key tools for plant breeding. Using these techniques, the speed and efficiency of plant improvement processes can be significantly enhanced. Anther culture-based technologies have the potential to regenerate large numbers of doubled haploid plants without colchicine treatment. In an attempt to elucidate the influence of phytohormones on non-directly induced chromosome doubling, two synthetic auxins, 2,4-D and centrophenoxine, were tested in a wheat anther culture approach. Whereas the induction of androgenic embryo-like structures (ELSs) was efficient for both auxins, we observed a significantly higher frequency of chromosome doubling when using 2,4-D than when using centrophenoxine. When 2,4-D was added to the induction medium, a positive correlation between the size of ELSs and their ploidy level was detected by flow cytometry. The morphological selection of ELSs, a process that was included in routine operations of the method without significantly extending the input of time and effort, facilitates the production of fertile DH plants with a frequency of 60 %. Our findings may contribute to a more efficient production of doubled haploid wheat plants using a colchicine-free anther culture approach.