Climate change, globalization and armed conflict are facilitating the spread of plant pandemics and threatening food production on which billions of people depend, scientists have said.
An “unprecedented” spread of a fungus infecting wheat across the world has led scientists to call for greater international collaboration in the genetic monitoring of crop species to minimize their destruction.
The corn borer fungus was first identified in Brazil in 1985 and gradually spread to neighboring countries. More recently, pandemics have emerged in Bangladesh and Zambia.
Conflicts
In Bangladesh in 2016, it destroyed around 15,000 hectares, covering more than 16% of the country’s wheat area and consuming up to 100% of yields, while in Zambia epidemics continued to spread. occur with varying severity since its arrival in 2018.
Scientists fear that the fungus could spread to other countries through the importation of infected seeds or through spores carried by the wind.
The wheat blast has already moved from eight to 21 districts in Bangladesh and scientists are particularly concerned that it could spread to China and India, the two biggest wheat producers in the world.
In a new study, an international team of scientists led by University College London and Sainsbury’s Laboratory, East Anglia, have confirmed that the fungus afflicting Bangladesh and Zambia – Magnaporthe oryzae – is of the same genetic lineage as that from South America, although the exact source could not be identified.
The authors wrote: “The occurrence of blast on three continents with climatic conditions highly conducive to its spread is unprecedented and represents a very significant threat to global food security which is exacerbated by the twin challenges of climate change and armed conflict. in major agricultural regions. .”
Diseases
They said the global community must learn from the Covid-19 pandemic and track the spread of the fungus using similar genetic monitoring methods used to track the spread and mutations of the coronavirus.
Publishing their work in the journal PLOS Biology, the scientists analyzed the genetic composition of the European corn borer using 84 simultaneous PCR tests.
In addition to tracing its international spread, the team found that the Rmg8 gene is resistant to the fungus while the disease is susceptible to the fungicide strobilurin.
They pointed out that genomic surveillance, especially in countries neighboring infected areas, provides the best method to understand how to control fungal spread.
Sainsbury’s Professor Nick Talbot said: “Only by truly understanding the enemy and understanding the pathogens that cause these diseases can we truly control them pre-emptively.
Emerge
“We have to assume that plant diseases are going to spread all over the world because of the impacts of climate change and globalization and we have to prepare for that.
“We need to be proactive rather than reactive, we need to anticipate diseases will move in and therefore plan accordingly.”
The researchers said further work is needed to understand how plant diseases such as the European corn borer can evolve to become resistant to pesticides and fungicides and to investigate other potential strategies as alternatives to the use of chemicals. .
Sainsbury’s Professor Sophien Kamoun said: “This project builds on the paradigm – best exemplified by the Covid-19 pandemic – that genomic surveillance adds a unique dimension to the coordinated response to infectious disease outbreaks.
“We need to remain vigilant and continue genomic surveillance of blast in Africa and Asia to identify variants of concern as they emerge.”
This author
Danny Halpin is the PA Environment Correspondent.
