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.
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!
So how do we solve this problem ?
Carmenceta, there is no easy answer to your question…
I am currently sitting in a lecture to do with use of fungicides for control. These are useful but of course not possible for everyone, especially on a small horticultural scale… http://frac.info/index.htm
Use of sulphur to aid your plant can help, and regular watering is good, as stressed plants are more likely to be infected.
Good gardening practice is my best advice; removing infected material, regular pruning to ensure airflow around plants (reducing humidity).
In future selective breeding and GM may help to generate plants resistant to mildews but the mildews will always adapt to such changes.
Have a look at the RHS website (https://www.rhs.org.uk/advice/profile?pid=253) for more info and please do not hesitate to send me some samples if you would like to know more… Thanks, Oli
we have [and have always had] mildew on our oaks which are part of a mixed tree wood planted 1998/9
do you want samples?
Susan, powdery mildew on Oak is very common in the UK, and globally I think.
But a sample of yours would be brilliant to increase my sampling distribution and also to ID it as there are at least three PM species it could be.
So, yes please go ahead, details for sending are here: http://blogs.reading.ac.uk/crg/powdery-mildew-survey/
Thanks, Oli