Track 1-03: Development and Impact of Sown Temperate Species

Description

Alfalfa (Medicago sativa L.) has a high potential for sustainable bioethanol production, particularly because of its low reliance on N fertilizer (Samac et al. 2006). Genetic improvement for the accumulation of readily fermentable non-structural carbohydrates (NSC) and the saccharification of structural carbohydrate (SC) could significantly increase ethanol conversion rate. Genetic gains for these traits are tributary to the availability of screening techniques for the precise identification of superior genotypes with increased potential for the production of fermentable carbohydrates.

When assessing the genetic variability of parameters linked to cellulosic ethanol production (concentrations of NSC and SC), our results showed a large genetic variability within and among winter hardy- and biomass-type alfalfa cultivars (Duceppe et al. 2012). We also developed an efficient enzymatic assay to measure alfalfa stem degrade-ability, based on the quantity of glucose released by a customized commercially available enzyme cocktail. Despite its robustness, this test is labour intensive, thus limiting analytical capabilities. Near-infrared reflectance spectroscopy (NIRS) was previously shown to successfully predict enzyme released glucose in corn stover (Lewis et al. 2010). This approach allowed us to screen a large number of lignified alfalfa stem samples and to identify superior genotypes. Our objective was to determine if it is possible to develop alfalfa cultivars with superior cell wall (CW) degradability.

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Selection for Improved Saccharification Efficiency in Alfalfa Stems Assessed by Enzyme-Released Glucose

Alfalfa (Medicago sativa L.) has a high potential for sustainable bioethanol production, particularly because of its low reliance on N fertilizer (Samac et al. 2006). Genetic improvement for the accumulation of readily fermentable non-structural carbohydrates (NSC) and the saccharification of structural carbohydrate (SC) could significantly increase ethanol conversion rate. Genetic gains for these traits are tributary to the availability of screening techniques for the precise identification of superior genotypes with increased potential for the production of fermentable carbohydrates.

When assessing the genetic variability of parameters linked to cellulosic ethanol production (concentrations of NSC and SC), our results showed a large genetic variability within and among winter hardy- and biomass-type alfalfa cultivars (Duceppe et al. 2012). We also developed an efficient enzymatic assay to measure alfalfa stem degrade-ability, based on the quantity of glucose released by a customized commercially available enzyme cocktail. Despite its robustness, this test is labour intensive, thus limiting analytical capabilities. Near-infrared reflectance spectroscopy (NIRS) was previously shown to successfully predict enzyme released glucose in corn stover (Lewis et al. 2010). This approach allowed us to screen a large number of lignified alfalfa stem samples and to identify superior genotypes. Our objective was to determine if it is possible to develop alfalfa cultivars with superior cell wall (CW) degradability.