Last year, Nishiwaki was surprised to find a M. sacchariflorus plant, which was adjacent to some M. sinensisplants,with heavy seed set. M. sacchariflorusin Japan normally spreads vegetatively rather than through seed. Nishiwaki collected this seed, grew it out, and then used flow cytometry to determine the genome size of each of plants. Genome size can be used to detect hybridization events. In analyzing several seeds, their research revealed three triploid plants, which, based on some preliminary molecular analysis, were confirmed to be hybrids.

Researchers hope these new triploid plants will express phenotypic traits similar to that of the high-yielding M. x giganteus. But if they don’t, Stewart said they can still serve as sources of genetic variation that might express resistance to recently identified diseases and pests in the M. x giganteus.

M.x giganteus, the first known natural Miscanthus hybrid, was originally found in Japan and then made its way to Europe where it was initially used as an ornamental grass for estates or large gardens, Stewart said. It’s a highly productive grass that’s cold-hardy, notably for plants that use C4 photosynthesis, which are mostly found in the subtropics and tropics.

Itis a popular candidate for bioenergy production because it can grow up to 15 feet tall, creating more biomass than other varieties of Miscanthus.

Stewart and his team have received funding to continue searching for hybrids and to build up a diverse collection of plants of several native Miscanthus species throughout Japan. This collection will serve as a resource for the Energy Biosciences Institute located in the Institute for Genomic Biology at the U of I. Future research will also address the phylogenetic relationship of these hybrids with other Miscanthustaxa, and also their agronomic potential relative to the commonly cultivated M. xgiganteus.  

Stewart’s research was published in the American Journal of Botany.

Researchers included Aya Nishiwaki, Shotaro Kuwabara, Hiroya Matuura, Ryo Akashi, Sachi Yamaguchi and Genki Ishigaki of the University of Miyazaki; Aki Mizuguti of the National Institute of Agro-Environmental Sciences; Yo Toma, Tomomi Miyashita and Toshihiko Yamada of Hokkaido University; and Lane Rayburn and Ryan Stewart of the U of I.