With the discovery of a hybrid of Miscanthus plants in Japan, researchers are no longer putting ‘all their eggs in one basket’.
“If M. x giganteus is the only variety available, there are certainly risks involved such as diseases or pests causing widespread establishment problems or yield losses,” says Ryan Stewart, Assistant Professor of Horticulture in the Department of Crop Sciences at the University of Illinois, USA.
“We are trying to find Miscanthus hybrids to increase our options. In doing so, it’s a way to hedge our bets.”
Miscanthus x giganteus is a sterile triploid (three sets of chromosomes) formed by a natural cross of Miscanthus sacchariflorus and Miscanthus sinensis. Because it is sterile, it can only be propagated by vegetative division, which is more difficult than propagating by seed.
“Because it’s a sterile clone, it’s more or less a dead-end for plant breeders because it can’t be improved through plant breeding,” Stewart says.
His team has investigated overlapping populations of tetraploid Miscanthus sacchariflorus and diploid Miscanthus sinensis in Japan hoping to find a triploid hybrid plant that may be similar in productivity to Miscanthus x giganteus. However, it is rare finding these in the wild.
“In Japan, even when two plant species are adjacent to one another, they may have very different flowering times, meaning the likelihood of finding a hybrid is very low,” Stewart adds.
With the help of Aya Nishiwaki of the University of Miyazaki and Toshihiko Yamada of Hokkaido University, Japan, Stewart’s team has found a Miscanthus sacchariflorus plant adjacent to Miscanthus sinensis plants with heavy seed sets – although Miscanthus sacchariflorus in Japan normally spread vegetatively rather than through seed.
Based on preliminary molecular analysis, the plants have been confirmed to be hybrids.
The hope is that these new triploid plants will have similar phenotypic traits to the high-yielding Miscanthus x giganteus. But if they do not, Stewart believes they can still serve as a source of genetic variation that might express resistance to recently identified diseases and pests in the Miscanthus x giganteus.
Miscanthus x giganteus can grow up to 15 ft tall, creating more biomass than other varieties of Miscanthus.