Biotechnology of miscanthus

Abstract

Miscanthus x giganteus is a natural hybrid C4 grass genotype of great size and of a proven utility for biomass cropping, but its growing range is restricted by cold susceptibility. New requirements for fermentability and many other characteristics have also arisen over the last 10 years. However, the Miscanthus x giganteus genotype is not very easily included in breeding programmes because it is a sterile triploid hybrid and cannot produce seed. The genetic resources of the parental species M. sinensis and M. sacchariflorus and related species are being collected, studied and analysed using many new genomic and transcriptomic molecular tools. Breeders have selected new cultivars from within the genetic pool of Miscanthus sinensis and have also created new Miscanthus x giganteus and other interspecific hybrids. There is also progress in creating new intergeneric hybrids with close relatives such as sugarcane and sorghum. Initially the main purpose of biotechnology research was to develop cheaper micro-propagation methods for Miscanthus x giganteus, because rhizome propagation was so expensive. More recently, methods of in vitro polyploidy have been developed in the hybrid and two parental species, which will allow the creation of new hybrid combinations and the exploitation of the greater size of polyploids. Genetic transformation by particle bombardment and via Agrobacterium has also been achieved relatively recently and is now being applied to several characteristics potentially involved with fermentation for ethanol production.