There has recently been a substantial amount of research done on sorghum as a biofuel feedstock because of its low water usage and fertilizer requirements. In the first session after lunch on Tuesday April 20, 2010, Vermerris, Saballos, Kresovich, Murray, Rooney, Pederson, Sattler, and Xin research on the genetics of sorghum was presented. They said that Sorghum is best known as a grain crop, but sweet sorghum is very similar to sugar cane in chemical composition. There is also forage sorghum. Sorghum plants are diploid, C-4, annuals that are produced from seeds; they have low-input requirements and a high yield potential. The genome has been sequenced. When sugar production is examined, sorghum “stacks up favorably against sugar cane and switchgrass,” according to the presentor. According to Vermerris et al., the ultimate goal in sustainable biofuel production is to minimize inputs and maximize outputs—this applies to grains, biomass, and sugar. They would ideally like to optimize crops to produce food, fodder, heat, biofuels, and biproducts.They said that sugar accumulation is poorly understood and that it depends on juice volume and cell wall modification. Their research is being done on several groups of Brown Rib Mutants; two of these mutants are the Bmr6 and the Bmr 2 mutants. Of the 19 Bmr mutants, Bmr 2 and Bmr 6 are the most promising for genetic modification. The mutants are being used because they are easier to convert to higher sugar yielding plants. There are 14 different copies of this one particular gene related to sugar production in sorghum, so it has taken them a long time to actually isolate it. Eventually, they succeeded. Vermerris et al. used several mapping techniques and then different cloning techniques in their research. The results will be published later this year.
Summary of the 1:00 session on the Genetic dissection of bioenergy traits in Sirghum by Vermerris, Saballos, Kresovich, Murray, Rooney, Pederson, Sattler, and Xin