An Attempt to Restore the Fertility of Miscanthus × giganteus

Abstract

Miscanthus × giganteus is a popular industrial plant with great potential in ecological agriculture. It forms numerous rhizomes that are important in the sequestration of carbon dioxide. The plant can be a source of lignin and cellulose, biomass for renewable energy production, and can be used in small garden architecture, or to strengthen the banks of landslides. Breeding this species is difficult, as it is a sterile allotriploid with 57 chromosomes. The aim of the study was to obtain fertile plants of this species by treating its callus and regenerants with chromosome doubling agents such as colchicine, oryzalin, trifluralin, and caffeine at variable concentrations and durations. Callus cells naturally showed large variations in the number of chromosomes but only euploid cells regenerated plants. Treatment of the regenerants with 1252 µM colchicine for 18 h allowed for obtaining two hexaploid shoots; however, they died before flowering. Colchicine and oryzalin stimulated the formation of mixoploid shoots. The investigated substances, except for caffeine, were highly toxic to plants. M. × giganteus plants with 114 chromosomes may die because such a high number of chromosomes may be unfavorable for cells of this species.