Chemotaxonomy of domesticated grasses: a pathway to understanding the origins of agriculture

Jardine, Phillip E.; Gosling, William D.; Lomax, Barry H.; Julier, Adele C. M.; Fraser, Wesley T.

Abstract

The grass family (Poaceae) is one of the most economically important plant groups in the world today. In particular many major food crops, including rice, wheat, maize, rye, barley, oats and millet, are grasses that were domesticated from wild progenitors during the Holocene. Archaeological evidence has provided key information on 15 domestication pathways of different grass lineages through time and space. However, the most abundant empirical archive of floral change-the pollen record-has been underused for reconstructing grass domestication patterns, because of the challenges of classifying grass pollen grains based on their morphology alone. Here, we test the potential of a novel approach for pollen classification based on the chemical signature of the pollen grains, measured using Fourier Transform infrared (FTIR) microspectroscopy. We use a dataset of eight domesticated and wild grass species, classified using k-nearest 20 neighbour classification coupled with leave one out cross validation. We demonstrate a 95% classification success rate on training data, and an 82% classification success rate on validation data. This result shows that FTIR spectroscopy can provide enhanced taxonomic resolution enabling species level assignment from pollen. This will enable the full testing of the timing and drivers of domestication and agriculture through the Holocene.

Citation

Jardine, P. E., Gosling, W. D., Lomax, B. H., Julier, A. C. M., & Fraser, W. T. (2019). Chemotaxonomy of domesticated grasses: a pathway to understanding the origins of agriculture. Journal of Micropalaeontology, 38(1), 83-95. https://doi.org/10.5194/jm-38-83-2019

• Journal Article Type: Article
• Acceptance Date: May 21, 2019
• Online Publication Date: Jun 7, 2019
• Publication Date: Jun 7, 2019
• Deposit Date: May 24, 2019
• Publicly Available Date: May 24, 2019
• Journal: Journal of Micropalaeontology
• Print ISSN: 0262-821X
• Electronic ISSN: 2041-4978
• Publisher: Copernicus Publications
• Peer Reviewed: Peer Reviewed
• Volume: 38
• Issue: 1
• Pages: 83-95
• DOI: https://doi.org/10.5194/jm-38-83-2019
• Public URL: https://nottingham-repository.worktribe.com/output/2090178
• Publisher URL: https://www.j-micropalaeontol.net/38/83/2019/