Mutagenesis and Genomic Analysis in the Bioenergy Species Arundo donax

Giant reed (Arundo donax L.) is a perennial C₃ Poaceae species of emerging interest for bioenergy and phytoremediation exploitation. Recent investigations highlighted its high efficiency as to carbon accumulation and biomass production in the Mediterranean environment (>40 t of dry matter/ha/year), and for biogas or second generation bioethanol production. A. donax completely lacks sexual reproduction and only propagates vegetatively. As a  consequence, very little genetic variation is found between naturally occurring ecotypes precluding breeding efforts. We utilized physical mutagenesis with gamma and Fast-Neutron irradiation treatments of in-vitro leaf-derived plant materials in order to increase the genetic variability of the species. For gamma-ray treatment, LD50 was reached with irradiation doses between 40 and 60 Gy. Plants were regenerated, hardened in pots and transferred to the field after 11-18 months. A total of approx. 1,100 independently regenerated plants are currently available and phenotypic observations have started. The nature of the induced mutations is being investigated by means of a two-enzyme Genotyping-By-Sequencing approach on a subsample of the collection.  To our knowledge, these are the first results of artificially induced mutagenesis in A. donax. Project funded by the FP7 EU program WATBIO.