Mutagenesis and Genomic Analysis in Arundo donax

Arundo donax L. (giant reed) is a perennial C3 Poaceae species of Mediterranean-subtropical origin and is characterized by high carbon accumulation efficiency, making it one of the most promising plants for bioenergy and phytoremediation exploitation. A. donax is highly polyploid, completely lacks sexual reproduction and propagates vegetatively. Very little genetic variation is found between ecotypes, which makes A. donax domestication and genetic improvement a challenge. We utilized physical mutagenesis with Gamma and Fast-Neutron irradiation treatments of A. donax in-vitro cultures in order to increase the genetic variability of the species. For the Gamma-ray treatments, LD50 was reached with irradiation doses between 40 and 60 Gy. Plants were regenerated, hardened in pots and transferred to field. A total of approximately 1,100 independently regenerated plants are currently available and mutants for plant height and habitus, leaf shape and color and other traits have been identified. We have additionally started to phenotype the collection for mutants affected in cell wall/cellulose/lignin, in order to identify clones potentially improved in bioenergy production. To our knowledge, these are the first results of artificially induced mutagenesis in A. donax. The molecular nature of induced mutations are being investigated with NGS-based genotyping means. Project funded by the FP7 EU program WATBIO.