Investigation into the suitability of spring triticale (×Triticosecale Wittmack) for bio-ethanol production in the Western Cape

[摘要] ENGLISH ABSTRACT: In the Western Cape small grain cereals, triticale (×Triticosecale Wittmack exA. Camus) in particular, appear to be among the most promising starch-carrying rawmaterials for the production of bio-ethanol. A core group of cultivars and lines fromthe Stellenbosch University Plant Breeding Laboratory spring triticale breedingprogramme were subjected to initial testing for the purpose of ethanol production.They underwent multi-location field-testing across six (season 2006–2007) and nine(season 2007–2008) locations representing the Western Cape cereal production area.Climatic conditions during the study were characterised as generallyfavourable, especially in the 2007 season. During the season, trials were visited inorder to make in situ observations. Disease susceptibility was given specific attention.After harvesting, grain yield (kg.ha-1), test weight (kg.HL-1), total starch content inwhole grain (%), amylose/amylopectin ratio, protein content (%), ethanol output(L.tonne-1) and ethanol yield (L.ha-1) were analysed.Near infra-red reflectance spectroscopy calibration models were developed formoisture and starch contents. The best calibration based on whole grain spectra formoisture content had RPD = 1.691, R2 = 0.657 and SEP = 0.271%, and for starchcontent RPD = 1.646, R2 = 0.634 and SEP = 1.356%. Calibrations developed frommilled grain showed better results for moisture content RPD = 2.526, R2 = 0.843, SEP= 0.182%, and for starch content RPD = 1.741, R2 = 0.673, SEP = 1.277%. Thesecalibrations are suitable for rough screening of samples.In the 2006 season, starch yield was highly positively correlated with grainyield (R2 = 0.988, P <0.001). Both starch yield and grain yield were positivelycorrelated with days to heading (R2 = 0.533 and R2 = 0.556, respectively; P <0.001). The 2007 season was characterised by a generally higher starch yield (2952–3142kg.ha-1, 95%CI) compared to the 2006 season (2077–2315kg.ha-1, 95%CI).Starch yield was strongly positively correlated with grain yield (R2 = 0.975,P <0.001). Test weight demonstrated weak positive correlation with ethanol yield(R2 = 0.238, P <0.01) and grain yield (R2 = 0.279, P <0.001). Mean ethanol outputranged between 466–477L.tonne-1 at the 95%CI. Ethanol output was demonstrated tobe more dependent on starch and other polysaccharides accessibility to enzymaticdigestion than on the total starch content as such. The best lines for ethanol output inthe 2007 season were G2, D3 and H2 for the Swartland region, and D3, G2 and D1for the Overberg region.The best triticale lines under investigation showed their potential from abiological point of view to be a suitable crop for ethanol production in the WesternCape, with the achieved ethanol yield ranging between 2446–2625L.ha-1 at the95%CI. For the Swartland region the best genotypes for ethanol yield were D1, H1and D2, and for the Overberg H1 and G2. The 23 best lines were selected from theelite and senior blocks, and then used for the establishment of a recurrent massselectionpre-breeding block.

[发布机构] Stellenbosch University