Using population genetics, scientists confirm origins of root rot in Michigan ornamentals

June 03, 2019

Floriculture, the growing of flowering and ornamental plants for gardens and floristry, is an economically important industry in Michigan, which ranks third in the United States for the wholesale value of floriculture products. The health of these crops is threatened by many diseases, including Pythium ultimum, a water mold that infects the roots of popular plants including poinsettia and geranium. The mold results in plant stunting, reduced plant quality, and root and crown rot. Despite educated efforts to improve control of this pathogen, root rot occurs annually for many growers.

To improve management strategies, a team of scientists used population genetics to gain insight into root rot of floriculture crops. They developed a set of small repetitive sections of DNA, known as simple sequence repeats (SSRs), to analyze root rot pathogen populations from various Michigan greenhouses and found that these populations were similar regardless of the plant type, growing season, or location.

There is a continuous exchange of plant materials, such as seedlings and cuttings, among greenhouses throughout Michigan. This study confirmed for the first time that the root rot pathogen is likely moved unnoticed within the state via infected plant material as early symptoms of root rot are easily overlooked. By using SSRs, scientists were able to confirm that the same root rot pathogen populations were responsible for all plants tested over a two-year period.

This research reveals the necessity for new strategies to eradicate this pathogen from greenhouses as current control strategies are not effective and the pathogen has developed a resistance to a popular fungicide. The scientists recommend greenhouse growers focus on improving scouting of all incoming plant material to prevent the root rot from entering their growing environment. On a broader scale, they recommend multi-faceted control strategies to delay or reduce the occurrence of fungicide-resistant populations.
-end-
More details about this study can be found in "Population Structure of Pythium ultimum from Greenhouse Floral Crops in Michigan" published in Plant Disease Volume 103, Number 5, published May 2019. Plant Disease is an international journal that publishes research on new, emerging, and established plant diseases.

American Phytopathological Society

Related Pathogen Articles from Brightsurf:

Cell-autonomous immunity and the pathogen-mediated evolution of humans
Although immune responses are generated by a complex, hierarchical arrangement of immune system organs, tissues, and components, the unit of the cell has a particularly large effect on disease progression and host survival.

Microbial genetics: A protean pathogen
The bacterium Helicobacter pylori is linked to increased risk of stomach cancer, and is genetically highly variable.

"Winter is coming": The influence of seasonality on pathogen emergence
Seasonal fluctuations drive the dynamics of many infectious diseases. For instance, the flu spreads more readily in winter.

Fungal pathogen disables plant defense mechanism
Cabbage plants defend themselves against herbivores and pathogens by deploying a defensive mechanism called the mustard oil bomb.

The disease pyramid: Environment, pathogen, individual and microbiome
Researchers from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), the Université de Toulouse and the Helmholtz Centre for Environmental Research (UFZ) show how the microbial colonisation of the organism influences the interactions between living organisms, the environment and pathogens, using amphibians like frogs as examples.

Global spread of the multi-resistant pathogen Stenotrophomonas maltophilia
An international consortium found a remarkable global spread of strains of a multi-resistant bacterium that can cause severe infections - Stenotrophomonas maltophilia.

New information about the transmission of the amphibian pathogen, Bsal
Using existing data from controlled experiments and computer simulations, researchers with the University of Tennessee Institute of Agriculture have found that host contact rates and habitat structure affect transmission rates of Bsal among eastern newts, a common salamander species found throughout eastern North America.

New pathogen threatens fennel yield in Italy
A new fungal genus and species Ochraceocephala foeniculi causes fennel yield losses of about 20-30% for three different cultivars.

Study shows CRISPR effectiveness against colitis pathogen
Research at North Carolina State University shows that the CRISPR-Cas system can be used to effectively target and eliminate specific gut bacteria, in this case Clostridioides difficile, the pathogen that causes colitis -- a chronic, degenerative disease of the colon.

X-ray eyes peer deeper into deadly pathogen
In a new study, researchers at the Biodesign Center for Applied Structural Discovery and their international colleagues examine a key membrane protein responsible for the tularemia bacterium's prodigious ability to infect the body and cause illness.

Read More: Pathogen News and Pathogen Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.