Miscanthus can be vegetatively propagated by rhizome division but this process is time consuming. Developing an efficient tissue culture system would provide an alternative to rhizome division and be useful for breeding purposes. Tissue culture enables a large number of plants to be generated and stored regardless of the season. In addition, the risk of transferring diseases between fields is lower than propagation by manual rhizome separation [141].

Somatic embryogenesis and clonal propagation are two methods used for in vitro prop­agation of Miscanthus. With somatic embryogenesis, considerable differences exist in the capacity of explants types of the same genotype to produce an embryogenic callus and regenerate plants [142, 143]. The growth stage of inflorescences used for the somatic embryogenesis is very important, with younger inflorescences showing a significantly higher callus induction rate than more developed inflorescences [144,145]. Immature inflo­rescences are abundant and can easily be obtained from field-grown M. x giganteus during the summer or from greenhouse grown plants throughout the year. In vitro propagated plants are more cold tolerant in their first season than plants obtained in vivo [146]. Plants propa­gated from rhizome division are larger and have a higher yield than plants propagated via somatic embryogenesis [66]. In clonal propagation involving organogenesis, new plants are produced from shoots obtained from a culture of axillary buds [64, 147]. Plantlets from vegetative regeneration are genetically identical (Rambaud, personal communica­tion). In addition, clonal propagation can also be applied to seedlings. Figure 4.7 presents the different stages of the clonal propagation of Miscanthus from seeds.

This last efficient plant regeneration system would be helpful for genetic improve­ment through future biotechnology research. It is interesting, for example, to handle tissue culture in order to produce transgenes. Recently, particle bombardment-mediated transformation [148] and Agrobacterium transformations [149] were used to insert genes of interest in Miscanthus genome for agronomical genetic traits and introduce genetic variations.