African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12209

Full Length Research Paper

Relationship between 2-acetyl-1-pyrroline and aroma in Uganda rice populations with Oryza (barthi, glaberrima and sativa) backgrounds

David Ocan
  • David Ocan
  • Department of Agricultural Production, College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
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Rongrong Zhang
  • Rongrong Zhang
  • School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, 4072, Australia.
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Martin Odoch
  • Martin Odoch
  • Department of Agronomy, Faculty of Agriculture and Environment, Gulu University, P. O. Box 166, Gulu, Uganda.
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Michael Kanaabi
  • Michael Kanaabi
  • National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
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Angele Pembele Ibanda
  • Angele Pembele Ibanda
  • Department of Agricultural Production, College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
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Agnes Akwero
  • Agnes Akwero
  • Department of Agricultural Production, College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
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Bill Williams Khizzah
  • Bill Williams Khizzah
  • Department of Agronomy, Faculty of Agriculture and Environment, Gulu University, P. O. Box 166, Gulu, Uganda.
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Ephraim Nuwamanya
  • Ephraim Nuwamanya
  • National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
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Jimmy Lamo
  • Jimmy Lamo
  • National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
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Melissa Anne Fitzgerald
  • Melissa Anne Fitzgerald
  • School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, 4072, Australia.
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Venea Dara Daygon
  • Venea Dara Daygon
  • School of Agriculture and Food Sciences, University of Queensland, St Lucia, QLD, 4072, Australia.
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Patrick Rutimbanzigu Rubaihayo
  • Patrick Rutimbanzigu Rubaihayo
  • Department of Agricultural Production, College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda.
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  •  Received: 29 August 2019
  •  Accepted: 18 October 2019
  •  Published: 30 November 2019

Abstract

The sweet popcorn aroma conferred by 2-acetyl-1-pyrroline (2AP) is a highly economic trait of rice grain attracting premium price worldwide. This research study was conducted to determine the levels of 2AP in Ugandan rice lines with the aim of establishing a better understanding on the level and classes of 2AP and aroma phenotype. Concentration of 2AP was assayed using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF-MS) in tandem with sensory evaluation. Substantial variations in aroma intensity within and between the Uganda rice families were recorded. However, the levels of aroma variation were strongly influenced by the type of rice, and the breeding population it was derived from. Hence, three aroma based categories, namely, nonaromatic, moderately aromatic and highly aromatic were identified. GC with complementary sensory evaluation suggested a highly complex nature of rice aroma, as several rice lines were re-classified on the basis of this study. The 2AP contents and aroma intensity for genotypes with O. glaberrima were low compared to O. sativa and O. barthi. Genotypes of Supa 5, Supa 1052, Yasmin aromatic and MET 3 contained high 2AP levels whereas MET 16, MET 6, AGRA 78, AGRA 55, AGRA 41 and Sande TXD 306 exhibited moderate 2AP contents. Therefore, in developing an optimal breeding strategy aimed at improving the aroma in rice, quantitative information about 2AP and complementary sensory evaluation are a prerequisite.

 

Key words: Grain aroma, sensory evaluation.