Evaluation of advanced sorghum lines for bioethanol production related traits

Transcription

1 Evaluation of advanced sorghum lines for bioethanol production related traits Nemera Shargie - ARC, South Africa Awadhi Mashombo Dep t of Agric., Dodoma, Tanzania Julia Sibiya - UKZN, South Africa 21 st Century Global Sorghum Conference, April 2018 Century City, Cape Town

2 Background Sorghum has diversity of uses human consumption, animal feed, raw material for industry and can be processed into malted foods, beverages and beer, dried stalks used as a cooking fuel the production of ethanol Bioethanol production from renewable feedstocks plays an important role in reducing both the environmental pollution and consumption of crude oil. Grain sorghum high starch content drought, heat, waterlogging tolerance and salinity resistance rapid growth (short life cycle) wide adaptability nitrogen usage efficiency

3 Cont d Global sorghum production and Fuel ethanol production Fig 1 Global Sorghum producing areas (FAOSTAT, 2016)

4 Cont d Ethanol yield and conversion efficiency are the two most important quality traits of cereal grains when they are used to produce fuel ethanol Both ethanol yield and fermentation efficiency have been used to evaluate the performance of grain sorghum as a feedstock in ethanol production Starch is hydrolysed to fermentable sugars, which in turn fermented to ethanol and carbon dioxide

5 Cont d Ethanol yield and efficiency of conversion - starch content of the grain, tannin content in the grain, protein content and digestibility. The starch content in most sorghum genotypes ranges between 60 77%. On average this starch difference should result in up to 15% calculated difference in ethanol yield per unit grain used. Variation in starch content - growth environment, plant genetics, harvesting method and storage

6 Cont d In ethanol production the increase of the tannin content had a strong negative effect on the process efficiency In order to develop sorghum genotypes with desirable traits for ethanol production it is necessary to quantify agronomic and grain quality characteristics of diverse set of sorghum germplasm

7 Objectives To quantify the agronomic and grain yield potential of sorghum germplasm To evaluate and identify sorghum lines/varieties based on starch content, protein content and protein digestibility.

8 Germplasm 50 accessions (45 of advanced breeding lines + 5 varieties/landraces) Field Evaluation Genotypes were evaluated in 3 replications of a 10 x 5 alpha lattice design at 2 locations. Lab Evaluation %starch analysed using Near-Infrared Spectroscopy (NIR) %protein-total soluble proteins were extracted according to (Kanellis and Kalaitzis, 1992) Protein digestibility: in vitro pepsin protein digestibility method as described by (Mertz et al., 1984)

9 Means and mean squares from ANOVA of 10 quantitative characters Character Range Mean MS Error MS LSD (P<0.05) C.V SD Days to 50% flowering ** Days to maturity ** Plant height (cm) ** Panicle length (cm) ** Panicle width (cm) ** No. of panicles/plot ** Panicle weight (kg/plot) ** Grain yield (kg/plot) ** No. of grains /panicle ** grain weight (g) **

10 Mean grain yield, %starch, %protein, and protein digestibility of selected sorghum lines Accession Grain yield (t/ha) %Starch %Protein Protein digestibility (%) 05Potch ELC # ELC # ELC # ELC # Framida ELC # ELC # ELC # ELC # ELC # , M Macia Maseka Range Mean

11 Starch content(%) Starch content (%) Red White Yellow Brown Light brown Colour group Colour group Fig. 3 Average starch content in grain sorghum according to grain colour groups Fig. 4 Average protein content according to colour groups Protein digestibility (%) Protein digestibility(%) Colour group Fig. 5 Average protein digestibility in grain sorghum according to grain colour groups protein content (%) Red White Yellow Brown Light brown Protein content(%) Red White Yellow Brown Light brown

12 Phenotypic correlation coefficients showing pair-wise association among starch content, protein content, protein digestibility and grain yield. Trait Starch content Protein content Protein digestibility Grain yield Starch content - Protein content -0.65** - Protein digestibility 0.66** -0.34* - Grain yield

13 Summary The 50 sorghum lines/varieties differed substantially in terms of both grain physical and chemical quality characteristics and potential bioethanol production performance Time of planting had significant impact on the performance of the genotypes The breeding lines/lines with high starch content, low protein content, and high protein digestibility were 05-Potch-151, ELC#47, ELC #69, ELC#45, and ELC#42 and showed desirable characteristics for bioethanol production

14 Cont d There are clear relationships between some grain quality characteristics and potential bioethanol production performance. Breeding lines with high digestibility potentially have better nutritional value than those with low digestibility, and these breeding lines can be good for human food and animal feed. Starch content and Protein content on whole sorghum grain seems to give useful estimates of these parameters and could be used for rapid prediction of bioethanol performance of sorghum lines in breeding programmes.

15 Acknowledgements