# Using DNA Metabarcoding to Identify the Floral Composition of Honey: A New Tool for I



## AmericasBeekeeper (Jan 24, 2010)

Using DNA Metabarcoding to Identify the Floral Composition of Honey: A New Tool for Investigating Honey Bee Foraging Preferences
Identifying the floral composition of honey provides a method for investigating the plants that honey bees visit. We compared melissopalynology, where pollen grains retrieved from honey are identified morphologically, with a DNA metabarcoding approach using the rbcL DNA barcode marker and 454-pyrosequencing. We compared nine honeys supplied by beekeepers in the UK. DNA metabarcoding and melissopalynology were able to detect the most abundant floral components of honey. There was 92% correspondence for the plant taxa that had an abundance of over 20%. However, the level of similarity when all taxa were compared was lower, ranging from 22–45%, and there was little correspondence between the relative abundance of taxa found using the two techniques. DNA metabarcoding provided much greater repeatability, with a 64% taxa match compared to 28% with melissopalynology. DNA metabarcoding has the advantage over melissopalynology in that it does not require a high level of taxonomic expertise, a greater sample size can be screened and it provides greater resolution for some plant families. However, it does not provide a quantitative approach and pollen present in low levels are less likely to be detected. We investigated the plants that were frequently used by honey bees by examining the results obtained from both techniques. Plants with a broad taxonomic range were detected, covering 46 families and 25 orders, but a relatively small number of plants were consistently seen across multiple honey samples. Frequently found herbaceous species were Rubus fruticosus, Filipendula ulmaria, Taraxacum officinale, Trifolium spp., Brassica spp. and the non-native, invasive, Impatiens glandulifera. Tree pollen was frequently seen belonging to Castanea sativa, Crataegus monogyna and species of Malus, Salix and Quercus. We conclude that although honey bees are considered to be supergeneralists in their foraging choices, there are certain key species or plant groups that are particularly important in the honey bees environment. The reasons for this require further investigation in order to better understand honey bee nutritional requirements. DNA metabarcoding can be easily and widely used to investigate floral visitation in honey bees and can be adapted for use with other insects. It provides a starting point for investigating how we can better provide for the insects that we rely upon for pollination.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0134735


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## kilocharlie (Dec 27, 2010)

Inconclusive, but great progress, especially in the DNA metabarcoding side of the research. The melissopalynology side does allow for some degree of confirmation, but microscopy appears a better confirm at this point.

We're on our way to being able to confidently identify honey sources 
This could become a very good learning tool for beekeepers. As the technology advances, and if it should become mainstream, we can train our tasebuds (confirmed by these techniques) and adjust our drops for most favorable locations and further maximize honey production.

It would need more repeatability, simplification for a beekeeper service's use, and near-real-time results. But when that happens, we could idealize our drops very quickly by moving towards dominant sources (which may be a surprise), reducing flight times of the foragers, really packing in the stores.

Nice find, and thank you for posting!


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