DNA auto spore trap
This new automatic spore sampler has been designed with funding from Innovate UK and AHDB to warn growers of imminent Infection risk to crops.
The sampler uses a novel way of sampling airborne spores and depositing them into a pot prepared for downstream analysis. The device samples 300 litres of air per minute, collecting particles in the air, such as fungal spores.
At the end of the User-defined sampling period, the sample is moved through a series of different processes, which enables the instrument to detect the amount of spores of a target species that were in the air during the sampling period.
To do this, the spores are broken open in order to release the DNA inside. Once broken open, a subsample of the disrupted spores is transferred to a tube of dried reagents within the device, in order to detect the DNA of a specific crop pathogen using DNA-specific assay.
This is a method to amplify a specific sequence of DNA so that the DNA can be detected. The DNA sequence is known in advance to be unique to the pathogen of interest. If DNA is amplified, it means that spores of the species of interest were present in the sample. The DNA assay works by carefully designed primers binding to the target DNA and replicating a piece of DNA many times so that the amount of DNA in the reaction increases greatly. The reaction takes place at a constant temperature, which is set by the user according to the selected assay , The DNA assay could be either an RPA or LAMP assay whenever stabilised dried reagents are available.
The resulting amount of DNA is quantified by a fluorescent dye that binds to DNA. Light is fired at the reaction tube to cause the fluorescence, which is measured every 5 seconds. This reading is transmitted automatically over-the-air using the unit’s internal 4G router fitted with an AnyNet Secure SIM, over a gsm network back to the AWS Cloud where it is analysed and reported in a matter of minutes , to advise growers on their crop protection risk before any infection has taken place.
The unit also has its own on-board weather station which relays the weather data to a database. As the weather data and spore release has such a bearing on infection risk, it is possible for the weather data to be combined with risk models and processed to inform on infection risk , this is already available for some diseases and more will be added. The information is then overlaid on a map so a disease risk is then available to growers via web page.
Currently it is possible to detect potato late blight (Phytophthora infestans) and we are currently developing a range of other different DNA assays to detect Sclerotinia spores, which affect oilseed rape (canola) and a range of vegetables, Yellow Rust of wheat, and we’re currently developing Sugar beet pathogens.
More assays are being developed to detect more and more plant pathogens. Without any changes, the instrument can be used in other crops that are affected by many other diseases. The instrument is set up to run multiple separate assays using the same sample, so it can monitor for several different pathogens every day.
Therefore it can help protect multiple crops on a farm throughout key times of the year. The instrument is powered by mains electricity so can be placed on a farm close to the crop ready to detect and report the first signs of spore release long before crop infection. The instrument is fitted with an AnyNet Secure SIM, this means it is not tied to any one network so it will use the best available network in the area where it is located.
Growers will be warned in time so they can protect their crops. This information could also be used by the growers to delay the application of pesticides when there is no risk, therefore reducing the amount of pesticides applied to crops and saving money. The instrument is extremely simple to operate is designed to run without intervention by the user for periods up to 8 days.
Through the WEB site, the instrument will inform the operators of its status, and when it will need refilling with the consumables. If the unit has an error or is running very low on consumables, it can get the WEB site to email the operators to get these issues resolved. The user can set up sampling periods to suit their requirements through a simple user menu in-built into the unit. The DNA test vials can be supplied prefilled with reagents. The user simply loads these into the instrument along with a small amount of liquid and new sample collection pots.
2 x AA 1.5v Alkaline Batteries for weather transmitter
|Unattended sampling period||
Up to 8 days