WORLD first Australian research is looking to better understand microbial colonies in the root zones of hydroponically grown greenhouse tomato crops.
The study involves using DNA samples from hydroponics.
A stronger rhizobiome helps plants grow better, produce more fruit and show greater resilience to pathogens.
The end goal is to establish a better understanding about the rhizobiome of tomatoes grown in hydroponic media in order to manipulate them for better plant health.
The project is a collaboration between the University of New England (UNE) and Costa, as part of the Future Food Systems Co-operative Research Centre (CRC).
The research has the potential to assist hydroponic crops globally.
Project lead Dr Gal Winter and industry-embedded PhD student Phil Thomas, from UNE, have set up trial plots of hydroponic tomatoes in close collaboration with the Costa Tomato glasshouses at Guyra.
"Hydroponic media are very different from the soil environment," Dr Winter said.
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"Crops grown in soil get all the nutrients from the soil, and it is very, very rich in microorganisms.
"It's challenging to study what's in the root zone of hydroponic plants, because there isn't a lot.
"The challenge is, how do we get a population of microorganisms [in that hydroponically grown plant's root zone] to support the plant?"
The team has set up an experimental glasshouse at UNE to experiment with different probiotic treatments for the plants.
Later, this will be used to test for different pathogens - by introducing pathogens into the root zones of the trial hydroponically grown tomatoes to see if the probiotic-treated plants handle them differently.
"Secondly, we have set up trial plants in a 'sample slab' at the Costa Group glasshouse facility in Guyra that emulates Costa's standard hydroponic system at the facility; with these, obviously we don't create any interference - we just see what is there," Dr Winter said.
"To the best of my knowledge, this is the first-ever study that uses DNA metagenomics on hydroponic materials."
Costa glasshouses technical development manager Paul Butterworth said the initial findings were very promising.
"We believe the project is progressing nicely and the information already coming from the project is having an influence on how we look at our crops. Exciting times ahead," he said.
Some of the promising initial results include the creation and demonstration of an effective sampling method to test the probiotics within the rootzone of hydroponic tomatoes; and the demonstration of probiotics persisting in the rootzone of hydroponic systems for a period of time - currently tested at 19 days from inoculation.
University of New England's Dr Winter said samples of the root zones of the trial plants were taken by drilling "core holes" into the slab.
"From these samples, we can ascertain the [hydroponic root zone's] microbial community through DNA analysis," Dr Winter sasid.
"But rather than employing 'classic microbiological methods' - creating cultures, putting them on plates, then examining these under a microscope - we're using a cutting-edge technique known as metagenomics. It is the most advanced technique available today.
"It basically takes the DNA and, through DNA sequencing, identifies a genome of everything that's there - all the microbes.
"We use a piece of equipment known as a MinIon to do this advanced DNA sampling. The device is so small it could fit in the palm of your hand - it's amazing.
"The overarching aim, once we understand what's in the hydroponic plant's rhizobiome, is to work out how best to manipulate that for better plant health.
"Ultimately, that allows us to develop tools for hydroponic growers that enable them to analyse and understand their plants' microbiomes on the go - and then say, 'now I need to apply this or that treatment' to strengthen their microbiomes.
"And our study is one of the first to do this sort of analysis."
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