Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
February 26, 2001
Fungi and bacteria to help grow plants in space, greenhouses
University of Guelph researchers are developing ways to use fungi and bacteria to protect crops grown without soil, work that will eventually help astronauts harvest vegetables in space. In the meantime, the scientists hope to keep Canada’s $1.5-billion-a-year hydroponic plant industry competitive and solve its associated groundwater problems.
The research team, which includes Guelph environmental biology professors John Sutton and Chris Hall and plant agriculture professor Bernard Grodzinski, recently received a three-year $360,000 grant from the Natural Sciences and Engineering Research Council. They will investigate biological methods of protecting hydroponic plants, which are vulnerable to root diseases that might normally be held in check by fungi or bacteria that live in natural soils.
“The lack of biological protection in the root zone of hydroponic plants allowing root-infecting pathogens to be very aggressive,” Sutton said. “When these get into a greenhouse’s hydroponic system, their numbers can simply explode.” So the scientists are “recruiting” some of these these microbes to work as agents in a soil-free environment and carry out functions similar to those in outdoor crops. As well, microbes are being selected to destroy root residues and toxic substances that accumulate in hydroponic nutrient solutions during long-term cropping. All this means that hydroponic plants should stay healthy and productive, whether they are grown in Canadian greenhouses or in manned space vehicles. “This research will help fill an enormous void in scientific knowledge. And over time, it will have direct applications and provide information to CRESTech and NASA to help maintain plant health and feed astronauts on long-duration space flights.”
But more immediately, it will help stop groundwater contamination by allowing hydroponic greenhouse growers to continuously recirculate nutrient solutions instead of discharging them into the environment, he said. “These solutions are discharged, sometimes continuously, from greenhouses because growers believe that this helps to reduce root disease, wilting and productivity losses. The practice can seriously pollutes ground and surface waters and places heavy demand on water supplies, especially in the urbanized regions of the Great Lakes. It is of major national and international concern to Canada and the United States.”
The goal is to develop communities of beneficial fungi and bacteria that can protect the root zone and sanitize nutrient solutions throughout the life of hydroponic crops, Sutton said. These microbial agents help fend off pathogenic organisms, immunize the plants against pathogen attack, and promote plant growth and productivity. Some microbes, when associated with roots, also immunize the foliage against a wide spectrum of diseases, he said.
The scientists are collaborating with greenhouse growers to pinpoint the causes of stress and disease in hydroponic plants. They are also identifying fungi and bacteria that will be the most effective in helping protect plants and promote growth and disease resistance. Tests are already under way in model hydroponic communities that have been set up in greenhouses on campus, and the first paper on a successful test of two bacteria and root disease was published in the Canadian Journal of Plant Pathology last December.
The research is being conducted in greenhouses that adjoin the Biological Systems for Terrestrial and Space Applications facility, where other Guelph researchers, headed by plant agriculture professor Mike Dixon, are studying how to grow plants under conditions that simulate those in outer space. “Not only will this project have immediate and direct applications for greenhouse growers, but it also complements the work being done by these scientists,” Sutton said. “It will ensure that the plants they are developing to grow in space will stay healthy and productive.”
Contact: Prof. John Sutton Department of Environmental Biology (519) 824-4120, Ext. 3938/4373
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