MISCANTHUS  genetic experiment © Aline Waquet

Miscanthus, a very promising plant...

The benefits of miscanthus

Miscanthus, a perennial crop that uses vegetative propagation methods, produces high yields thanks to a highly efficient nitrogen-recycling system. The crop can therefore be grown with very little nitrogen fertiliser, which accounts for its highly beneficial energy balance.

By Pascale Mollier - Maryse Brancourt-Hulmel - Hubert Boizard - Fabien Ferchaud, translated by Inge Laino
Updated on 04/19/2013
Published on 02/15/2013

Miscanthus harvest at Courcelles en Chaussy agricultural college.. © INRA, BERNARDI Yves
Miscanthus harvest at Courcelles en Chaussy agricultural college. © INRA, BERNARDI Yves

A perennial crop

Miscanthus is a perennial plant of the Poaceae family that resembles sugar cane.  It yields a crop each year thanks to rhizomes, underground storage organs that produce buds that develop to become stems (or canes).  Once planted, miscanthus produces one crop a year for up to 25 years.  The canes develop in summer and can reach three or four metres in Europe, depending on species. The canes are harvested starting from the second or third crop year, either in autumn or winter. The following cycle begins again in spring, from the rhizomes.

Miscanthus x giganteus bud ('Estrées-Mons).. © INRA, PREUDHOMME Matthieu
Miscanthus x giganteus bud ('Estrées-Mons). © INRA, PREUDHOMME Matthieu

Vegetative reproduction

Miscanthus uses vegetative reproduction methods; varieties are therefore clones of the plant. Fertile species of the plant can also reproduce by seeds.

A high-yielding plant

Miscanthus is a particularly promising crop plant thanks to its highly efficient use of nitrogen, water and sunlight. It is a C4 plant, meaning it produces a basic organic acid consisting of four carbon atoms during photosynthesis.

A highly efficient nitrogen recycling system

At the end of the vegetative cycle, after flowering, when the canes wilt and dry out, nitrogen is transferred from the exposed parts of the plant to the rhizomes, which serve as nitrogen storage organs for the next vegetative cycle”, explains Maryse Brancourt, who studies the plant and its genetic enhancement. “That is why we can grow miscanthus practically without nitrogen fertilisers, which makes the plant that much more beneficial, because it takes a lot of fossil fuel to produce nitrogen fertilisers.

A genome that resembles that of known plants

The drawback of miscanthus is that it has a large genome: a haploid genome is estimated at 2.5 billion base pairs. The base chromosome number of the Miscanthus genus is 19 chromosomes with ploidy levels that range from two to six times as much. Nevertheless, it has the tremendous advantage of being very close, taxonomically, to sorghum and maize, all three plants belonging to the Andropogoneae tribe. A recent comparative genomic study between M. sinensis and sorghum, maize, rice and Brachypodium distachyon (1) has even revealed that sorghum is the closest to miscanthus syntenically,* which dramatically expands the genomic resources available for miscanthus genetics and breeding.
*The two species have analogous gene sequences for the same chromosomes.

Experiments in Estrées-Mons

Two long-term experiments were begun in 2006 at INRA’s Estrées-Mons site, near Lille: “Biomass and Environment” and “Miscanthus Genetics”. Assays aim to identify those species that have the most energy potential when the entire plant is used, build knowledge of how the plant functions to adapt growing practices accordingly, and finally to assess production systems in terms of energy, the environment and from an economic point of view. These energy crop tests were implemented within the framework of the Industries and Agro-resources competitive cluster in Picardie Champagne-Ardenne, and of several research projects at national and European level (cf part 5 of this report).

(1)    Ma et al.2012. High resolution genetic mapping by genome sequencing reveals genome duplication and tetraploid genetic structure of the diploid Miscanthus sinensis. Plos One, 7(3): p. 1-11

Etymologically...

The name miscanthus refers to the floral biology of the plant and derives from two Greek words: mischos, which is the small stem or stalk that connects the flower to the stem and anthos, which refers to the flower itself.

Geographic origin of the Miscanthus genus (according to Hodkinson et al, 2002).

The origins of miscanthus

Miscanthus was introduced in Denmark from Japan in 1930. Miscanthus is a genus consisting of anywhere from 12 (sensu stricto) to more than 20 species (sensu lato). The number of miscanthus species varies because the genus includes natural inter-specific hybrids, of which the most well-known is M. x giganteus, a cross between M. sacchariflorus and M. sinensis. Many species occur naturally in Asia, especially China.