15-01: Improving water soluble sugar content in perennial rye-grass: Developing grasses for production of biofuels and bulk chemicals

The bioconversion of feedstock by fermentation to biofuels and other bulk chemicals is dependent on the quantity of accessible sugars. Soluble sugars are readily extractable and any increase in this fraction has implications in the economics of a biorefining process. Perennial rye-grasses are temperate grasses which can grow on marginal land, achieve similar biomass yields to other lignocellulosic crops used for biofuel production and require low annual inputs, especially when grown with clover as a nitrogen source. IBERS have embarked on breeding programmes to increase the levels of water soluble sugars (WSC) in these grasses, to improve their potential as a biorefining feedstock. Current varieties are highly digestible with low lignin content and WSC levels typically in excess of 30% (dry weight basis).

Studies have been carried out on genes involved in the synthesis and breakdown of these soluble sugars. Quantify trait loci (QTL) have been identified which explain some of the variation in WSC and segregation of homologue genes with phenotype has been observed. Findings will be presented and discussed in the context of enhancing the quality of ryegrass as a biorefining feedstock.