Sorghum bioenergy genotypes, genes and pathways
Abstract
Sorghum (Sorghum bicolor [L.] Moench) is the fifth most economically
important cereal grown worldwide and is a source of food, feed, fiber and fuel.
Sorghum, a C4 grass and a close relative to sugarcane, is adapted to hot, dry adverse
environments and this plant is a potentially important bioenergy crop for Texas. The
diversity of the twelve high biomass sorghum genotypes was analyzed using 50 simple
sequence repeats (SSR) markers with genome coverage. The accumulation of biomass
during sorghum development was studied in BTx623, an elite grain sorghum genotype.
Genetic similarity analysis showed that the twelve high biomass genotypes were
quite diverse and different from most current grain sorghum genotypes. The ratio of
leaf/stem biomass accumulation was higher early in the vegetative phase during rapid
canopy development and lower later in this phase when stem growth rate increased. This
resulted in an increasing ratio of stem to leaf dry weight during development. Numerous
cellulose sythase genes have been putatively identified in the sorghum genome. The
relative level of Ces5 RNA in leaves decreased during vegetative phase of development
by ~32 fold. There was no change in the relative abundance of Ces5 RNA in stems.
Also there was no change in the relative abundance of Ces3 RNA in either stem or leaves during the vegetative stage. The knowledge gained in this study may contribute
to the development of sorghum bioenergy hybrids that accumulate more biomass and
that are modified in composition to make them more amenable to biofuels production.
Citation
Plews, Ian Kenneth (2007). Sorghum bioenergy genotypes, genes and pathways. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2432.