Climate change, globalization and armed conflict are fueling the spread of plant pandemics and threatening food production that billions of people depend on, scientists say.
The “unprecedented” global spread of a fungus that infects wheat has led scientists to call for greater international cooperation in the genetic monitoring of crop species to minimize damage to crops.
Wheat blast fungus was first discovered in Brazil in 1985 and gradually spread to neighboring countries. More recently, there have been pandemics in Bangladesh and Zambia.
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In Bangladesh in 2016, it destroyed some 15,000 hectares, spread to more than 16% of the country’s wheat acreage, and consumed up to 100% of production, while in Zambia, outbreaks have continued since the outbreak began in 2018, with severe To varying degrees.
Scientists fear the fungus could spread to other countries by importing infected seeds or through windborne spores.
The wheat plague has moved from eight to 21 districts in Bangladesh, and scientists are particularly concerned that it will spread to China and India, the world’s two largest wheat producers.
In a new study, an international team of scientists led by University College London and Sainsbury Laboratories in East Anglia has confirmed that the fungus affecting Bangladesh and Zambia – Magnaporthe oryzae – is similar to the fungus in South America. The same genetic lineage, although the exact source could not be determined.
“The occurrence of wheat blast on three continents where climatic conditions are very favorable for its spread is unprecedented and poses a very significant threat to global food security, exacerbated by the twin challenges of climate change and armed conflict in key agricultural regions,” the authors write.
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They say the international community must learn from the Covid-19 pandemic and use similar genetic surveillance methods to track the spread and mutation of the coronavirus to track the spread of the fungus.
Publishing their work in the journal PLOS Biology, the scientists analyzed the genetic makeup of wheat germ using 84 simultaneous PCR tests.
In addition to tracking its international spread, the team also found that the Rmg8 gene confers resistance to the fungus, which is susceptible to the fungicide strobilurin.
They stress that genomic surveillance, especially in countries near infected areas, is the best way to learn how to control the spread of the fungus.
Professor Nick Talbot, from the Sainsbury Laboratory, said: “Only by really understanding the enemy, understanding the pathogens that cause these diseases, can we really pre-emptively control them.”
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“We have to assume that plant diseases will spread around the world through the effects of climate change and globalization, and we have to be prepared for that.
“We have to be proactive rather than reactive, we have to anticipate that the disease will change and plan accordingly.”
The researchers say further work is needed to understand how plant diseases, such as P. tritici, evolve resistance to insecticides and fungicides, and to investigate other possible strategies as alternatives to the use of chemicals.
Professor Sophien Kamoun, from the Sainsbury Laboratory, said: “The project builds on the paradigm – best exemplified by the Covid-19 pandemic – that genomic surveillance adds a unique dimension to a coordinated response to infectious disease outbreaks. dimension.
“We need to remain vigilant and continue genomic surveillance of wheat blast in Africa and Asia to identify worrisome variants as soon as they emerge.”
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Danny Halpin is the PA Environmental Correspondent.
