Citizen Science Samples – Update

You may be wondering what happened to the samples that were sent in as part of the powdery mildew citizen science scheme. Over the past month or so, I have been working with these samples with Waheed, so look no further than this update to find out!

Preliminary morphological examinations were conducted under the microscope.

Since mid-May, samples have been sent to us from across the British Isles for use in our powdery mildew research. We conducted initial host and morphological observations, which limited the identification to a small number of potential species. To ascertain the identity of these, however, molecular techniques are required.

One of the first steps in the whole process is the isolation of fungal genomic DNA. This involves grinding the sample using one of the most traditional and common methods: with a mortar and (micro-) pestle. To help break down the tissue on which the fungus is growing, liquid nitrogen is used. At -196°C, the plant and fungal material becomes very fragile and dust-like – perfect for breaking down the cells and their internal components.

Samples are then subjected to a DNA extraction protocol, which isolates DNA from the rest of the plant and fungal tissue. The fungal “barcoding” gene of interest is then amplified, sent for sequencing in Oxford using an overnight service, and ready to be analysed on computer-based software back in Reading.

Silica-dried material is cut into smaller pieces for grinding…

…with the help of some liquid nitrogen (–196 ºC) poured into the tubes…

…before using a micro-pestle to reduce the infected material to a fine “dust”!

These DNA sequences are compared on GenBank, an open-access collection of publicly-available nucleotide sequences for a huge range of organisms. So, without further ado, here are the results for our first nine citizen science samples!

Thank you to the Royal Horticultural Society, Botanical Society of Britain & Ireland and British Mycological Society for helping us to spread the word. Remember to keep sending in your material to help study the world’s most diverse and frequently encountered plant pathogenic fungi!