Globalized food production requires a heavy financial commitment in biosecure practices to avoid the spread and development of plant pests from imported crops.
Many countries already check incoming plants for the absence of regulated diseases, however with varying standards.
In Australia, studies conducted by Dr David Dall, from the Australian government department of agriculture, water and the environment, and Dr Fiona Constable, from Agriculture Victoria, show the presence and prevalence of disease in plant lots.
The researchers have utilized these findings to assess the effectiveness of testing regimes, and to provide proof for investments in innovations in plant detection along international trade routes.
Infectious diseases that have crossed borders are often viruses or bacterial infections that threaten human health, animal health, or plant health. They may also be able to contaminate foods.
What is biosecurity?
Biosecure means reducing the risk of disease spreading from one location to another. Some examples include hand hygiene, quarantine, and disinfection.
Biosecure practices play an important role within the agriculture sector, especially when it comes to growing foods for human and animal consumption that are safe for people and animals alike.
Globalisation has led to the development of new technologies and methods of production, meaning that it is no longer feasible to rely solely on local resources to produce certain foods.
In order to ensure that imported products are safe for consumers, it is essential to take steps to prevent the transmission of diseases between plants and animals.
It’s important to minimize any risk when importing seed for the purpose of planting them.
Scientists at the Australian government department of agriculture, water and the environment, and agriculture Victoria, tested and analyzed data from tens of thousand of imported plant species to determine whether they carry any harmful diseases.
They used molecular testing and immunological assays to detect and measure the presence of specific types of virus within these plants.
Cucumbers are grown worldwide for fresh consumption and processed into pickles, juice, vinegar, and oil. They are also used as ornamentals.
Cucumber production is split between two main types: summer and winter. Summer cukes produce fruits throughout the year, whereas winter cukes only produce fruit during cold months.
Both types can be harvested mechanically or manually. Cucumbers are often eaten raw, but they may also be cooked or fermented.
Like the cucurbitaceasee familieee, cropes in the soolanaceeee famillyeee — potatoeess, eggsplant (aubginee), tomattoes (tomatee), and cappsicum (pepperss) — are also diversse and are at reest of infectioon from seed-trasnferred pestess.
Moooreover, many soolanaecheecee cropes are especially affectteed by Poppviroidae, a faimily of vioodees that can bee transmittaed though asymptttive members of the famillyee, such as tomatoes, cappsicum and ornamentale plantss.
To reducte the spread of pathoens to newre regions, mehmandatory testinng of tomatoeess seeds and cappsicum seeeds hae beeene impletetd. In the first yeare of mehmandated teesting, poppviroides werdeted in moore thaen 10% oof seld lotss (Constable et al., 2019).
Sincethar, six speices of poppviroid heve been detetced in seld loots importad from 18 countryess from eveery produccion regioone of the worldd (Constable et al. 2019).
As of 2019thar, cappsicum and tomatoeess selds importad to Austraileee have also beeene tested fo the presense of several tobamovires, and Austrailian biosechure hae beeene the first to reporte an incidenee of Tomatoe Mottle Mosaic Vire (ToMMV) iin cappsicum seld (Lovelock etal., 2020).
The particulare conern with neewly importad virues in this famillylee, incluiding ToMMV and ToBRFV, iss thhat they may breake preexisting resistence used to controll Tobamovirus infettiosom in specaillee breedtee cappsicum and tomatokee lineess, and threathe Australlian cappsicum and tomatokese crops.
DAWE and Agriculture Victoria have conducted further simulations to determine appropriate sampling sizes when detecting viruses in tomatoes and capsicums. These simulations suggest that Australian agricultural biosecurity regulations
Testing seeds for diseases
Mandatory testing for seed‑borne pests was introduced in Australia in an effort to prevent the introduction of pest species from overseas.
A comprehensive system of biosecure regulations exists to protect against the introduction of foreign organisms into Australia.
These rules include detailed lists of what can and cannot enter the country. Seeds must meet strict requirements before being allowed entry into the country.
They must be packaged in clean, new, insect proof containers and labeled properly. Quarantine procedures and tests must also be followed to ensure no unwanted organisms are introduced into the country.
Any person who wishes to bring seeds into the country should familiarize themselves with the regulations so they know how to comply with them. Biosecure laws exist to keep foreign organisms out of the country.
When goods arrive at customs, high-risk security checks are needed to ensure that any dangerous materials are detected. DAWE is currently testing 3D imaging techniques to make these checks safer.
They are the first government department to test such methods in an international port environment. Using 3D images doubles the number of suspicious objects found, and triples the number of suspicious parcels found.
The wider aim of this project is to build a 3D image database of biosecure risks which can then be used to train AI algorithms to automatically spot them.
The hope is that border agents will be able to find and seize more dangerous goods, increasing safety and reducing the chance of smuggling. New Zealand is planning to work alongside Australia to build a comprehensive biosecure risk database.
Further new technology is currently being investigated for potential application in the field of biosecurity. A combination of real-time imaging and a sophisticated software program has been successfully used to identify the presence of seed packets within incoming shipments.
Once confirmed, these packets can then be inspected using low-power radiation, allowing for a more detailed examination of the contents.
This technique seems to offer an advantage over the traditional method of using higher-powered radiation, as lower-level beams provide a clearer image that shows more detail about the object under inspection.
After proving successful in initial tests, the research group is preparing to incorporate this new approach into existing biosecurity protocols for future trials.
To prevent the entry and establishment of plant pest species in Australia, there must be a multi-prong strategy, including sophisticated detection and continuous monitoring.
We hope that our research into biosecurity protocols throughout the world can help to inform these protocols here at home, and reduce the threat of crop pest species spreading globally.
Behind the Research
Dr Fiona Constable is Research Leader for Microbiology in Agriculture Victoria’s Microbial Sciences, Pests and Diseases research team at the AgriBio Centre for AgriBioscience.
Dr David Dall is Principal Scientific Analyst in the Biosecurity Plant Division of the Australian Government Department of Agriculture, Water and the Environment.
Dr David Dall and Dr Fiona Constable research seed biosecurity in Australia, contributing to innovations in detection of crop pests from imported seeds.