The Technology Used for Synthetic Polyploid Production of Miscanthus as Cellulosic Biofuel Feedstock

Abstract

Background: The contemporary bioethanol production technologies are based on the utilization of plant lignocellulosic biomass. These technologies require conducting regular search, breeding, and creation of new energy crops. In particular, significant attention is paid to plants of the genus Miscanthus - perennial grasses that have a great potential as renewable energy sources. The main advantages of representatives of this species are considered to be high biomass yield, cold tolerance, a low requirement to soil conditions, long-term use of plantation, etc. M. × giganteus is the most promising species of the genus. The last is a sterile allotriploid originated through the hybridization of M. sinensis and M. sacchariflorus. Due to the problem with sexual reproduction, there is a lack of genotypes necessary for plant breeding programs to improve this species. Thus, polyploidization is an indispensable approach for obtaining new genotypes of M. × giganteus. Objective: The aim of this work is to review the attempts and methodologies employed to induce polyploidy in plants belonging to the genus Miscanthus. Methods: For this purpose, the concentrations and duration of treatment with different antimitotic agents in species, within this genus, have been considered. Methods for ploidy level determination and evaluation of biological and biochemical traits in the resulting polyploids have also been reported. Results: The application of antimitotic agents in vitro is the most effective and commonly used method of polyploidization in Miscanthus. The most effective antimitotic compounds appeared to be the well-known dinitroanilines, such as oryzalin and trifluralin, as well as new dinitroanilines with significantly lower phytotoxicity level. Conclusion: Polyploidization in Miscanthus has been investigated by various research groups worldwide. Currently, polyploid forms of M. sinensis, M. sacchariflorus and M. × giganteus have been obtained. The biological and biochemical traits of the obtained polyploids differ significantly from their original forms. However, the challenge of fertility restoration of M. × giganteus has not been resolved yet.