Preliminary quantitative trait loci analysis for biomass traits in Miscanthus sinensis

In light of rising energy costs, lignocellulosic ethanol has been identified as a renewable alternative to the petroleum based transportation fuels. In an attempt to reach government mandated ethanol production levels, potential biofeedstock candidates have been investigated and accessions within the genus Miscanthus have been identified as leading contenders in the Midwestern United States due to their high yield and efficiency. The sterile nature of the widely studied M. x giganteus clone precludes crop improvement via traditional breeding methods. An alternative strategy to introduce genetic variability and advance performance is through the breeding of M. sinensis, one of the progenitor species of M. x giganteus. The obligatory outcrossing nature of Miscanthus prohibits the formation of inbred lines making it necessary to evaluate large segregating populations from crosses between heterozygous parents. In addition, a plant establishment period of three years is needed to accurately determine the true phenotypic performance of progeny. Establishing correlations between traits exhibited during the establishment phase and plot yields and developing a marker assisted selection program would allow earlier selection. With this in mind, a QTL study was conducted in a pseudo testcross mapping population segregating for flowering time, height, leaf width, and yield. An initial look at the genetic architecture underlying traits important to biomass production in a population of 221 progeny from the cross of M. sinensis accession ‘Grosse Fountaine’ with M. sinensis ‘Undine’ identified 42 QTLs across 15 traits. The use of spring emergence as a covariate to account for variation resulting from the establishment effect increased the power to detect QTLs. Synteny between sorghum and Miscanthus has been utilized to identify a plausible gene candidate underlying a flowering time QTL. This analysis sets the foundation for fine mapping, positional cloning, and the development of a marker assisted selection program in the ongoing effort to improve Miscanthus as a biofuel crop