Interspecific Hybridization Between Elephantgrass and Pearl Millet and Selection of Hybrids With High-Biomass Production and Enhanced Biosafety.

Elephantgrass (Pennisetum purpureum) is one of the best adapted, warm season perennial grasses for subtropical and tropical regions of the world. It is a C4 monocot and has the ability to produce large amounts of biomass. The biofuels industry has identified elephantgrass as one of the most productive feedstocks for lignocellulosic biofuel production in the southern US. However, elephantgrass is listed as invasive in Florida by the Florida Exotic Pest Plant Council. Plant propagation and establishment of new elephantgrass plantings occur through vegetative plant parts. Therefore, unlike most seeded crops, seed production is not necessary for elephantgrass biomass production and its suppression will significantly reduce its potential for invasiveness. Interspecific hybridizations between elephantgrass (2n=4x=28) and pearl millet (2n=2x=14) results in genotypes that display male and/or female sterility due to their triploid (2n=3x=21) nature. We produced more than 3000 triploid, interspecific hybrids between elephantgrass and pearl millet. Phenotypic variability present in these hybrids allowed selecting lines which produced similar or higher biomass amounts as the seed producing elephantgrass cultivar Merkeron. We will present data describing the biomass yield and the sterility of interspecific hybrids evaluated in replicated field trials.