When some biologists say that “without bees there would be no life”, this is not an exaggeration. Without pollinating insects, such as bees or bumblebees, a third of the food would disappear , and also part of the forage with which we feed the animals we raise and eat, according to the member of the Board of the Fundación Amigos de las Abejas, Jesús Apple tree. In economic values, the pollination of bees is estimated annually at two hundred and eighty-five billion euros worldwide.
Unfortunately, the bee population is in great decline in the UK and across Europe. Factors threatening bees include the widespread use of pesticides, parasites, disease and, of course, climate change; But the loss of biodiversity poses a particularly specific threat to bees and other wild pollinators: the wild flowers on which they depend are also in severe decline.
So one way to help increase bee numbers is to plant the right wildflowers , providing better habitat for pollinators to disperse, nest, and reproduce. And while farmers know this, what is less clear is which plant species are most preferred among the different pollinators and how this might change over time and under different environmental conditions.
Farmers need to know this information. What’s more, we could say that knowing is vitally important, not only to save the bee population, but also to ultimately save ourselves.
Now that we know the importance of knowing the preferred wildflowers of pollinators such as bees, we can understand the relevance of the study carried out by the Earlham Institute of the United Kingdom : here, a team of researchers has just published a rapid analysis method called ‘Reverse Metagenomics’ (RevMet) that can identify the plants that individual bees visit using the so-called MinION, a portable DNA sequencer from Oxford Nanopore Technologies.
A technique that represents quite a revolution since, historically, scientists often use optical microscopy to identify the pollen grains collected by each of the bees, one by one, which was an impractical and time-consuming method. Thus, this innovative method allows obtaining a more precise understanding of the location of bees , to identify their favorite plants, without the need for laborious manual inspection of pollen.
The CSI of bees
As if it were a case of forensic medicine, the technique can identify the amount of insect DNA present in each of the pollen samples, thus identifying which are the plant species most visited by them.
PhD student Ned Peel, who carried out the research at the Leggett Group of the EI, explains it this way in a press release: “From a mixed sample of pollen, in addition to being able to find out which species of bees have visited the plant to which belongs, we can also measure the relative amount of each type of pollen. This type of analysis can be applied, not only to increase the population of pollinators, but also to help us sustainably improve the production of crops that depend on pollinators “.
In the work, the researchers analyzed 49 different species of wild plants from the UK.
This technique not only allows you to check which plants the bees like to pollinate; it also allows us to understand whether certain wildflowers compete with agricultural flowers for pollinators , or the behavior of pollinators over large areas and types of land.
Finally, the method could also be used to study other mixed samples, such as manure, for diet analysis; and air, to identify airborne allergenic pollen and crop pathogens.
Source : Semi-quantitative characterization of mixed pollen samples using MinION sequencing and Reverse Metagenomics (RevMet) (2019) Methods in Ecology and Evolution. https://www.biorxiv.org/content/biorxiv/early/2019/02/16/551960.full.pdf
