KFU scientists come up with a way to protect potatoes from a dangerous disease

Kazan microbiologists have found strains of bacilli that can cope with the causative agents of Fusarium wilt, or the 'dry rot' of the vegetable

The Kazan Federal University has developed a unique technology that will save both large farmers and ordinary gardeners from the serious problem. It's about a way to protect potatoes from the dangerous common disease — Fusarium wilt, or dry rot, as it is also called. Scientists have discovered strains of bacilli, which were active against the causative agents of fungal diseases. Read the details in the material of Realnoe Vremya.

What is the danger of Fusarium wilt?

Ayslu Mardanova, Doctor of Biological Sciences, Associate Professor of the Department of Microbiology at the Kazan Federal University, told Realnoe Vremya about the new development. To begin with, the interlocutor of the publication outlined how dangerous the disease itself is for potatoes.

'Fusarium wilt firmly occupies the second line in the ranking of the most common diseases of potatoes,' the scientist explained. 'The disease leads to a decrease in productivity of crops and damage to the tubers during storage. Since 2010, the disease has become increasingly common — it is associated with climate change, warming.'

The expert said that Fusarium wilt prefers heat and dryness. Even a small period of abnormal heat can provoke the progression of the disease.

'Among fusarium fungi, there are useful and pathogenic ones," the specialist said. “They are the usual inhabitants of the soil. But pathogens, if they become too many, populate the plant, thereby causing its premature death.'

Microorganisms enter through the roots into the vessels, causing their blockage. The nutrients and water stop flowing, and the plant withers.

'It is possible to lose the crop during the growing season,' said the interlocutor of Realnoe Vremya. 'And it is possible also in winter. Fusaria penetrate tubers without causing visible damage. You put conditionally healthy potatoes in storage, and then you will have a surprise. After 2-3 months, voids with mycelium form in the tubers.'

According to the expert, losses due to Fusarium wilt can reach from 20 to 60 per cent of the crop. Some Fusarium wilt produce micro-toxins. They are not very poisonous, but they tend to accumulate in the body. Regularly eating contaminated food, a person risks being poisoned one day.

Strains and resistance

'We have two main areas of work,' the scientist said. 'The first is the evaluation of potato varieties for resistance to Fusarium wilt. And the second — the study of microorganisms that inhabit the roots of potatoes.'

By the way, microbiologists have found out that a lot of fusaria lives in the roots of potato of the Zhukovsky early variety. At the same time, this potato is very sensitive to Fusarium wilt.

'At first, the experiment to assess the stability was carried out with 3-5 varieties of potatoes,' said Mardanova. “Now the line has been expanded. It already includes about 50 varieties.

Mardanova explained that each region has its own strains: 'We have collected and characterised a collection of strains specific to Tatarstan.'

According to the interlocutor of the publication, much is still unknown about the interaction of potatoes with pathogens. Scientists cannot explain what molecular interactions a particular strain affects potatoes.

'When a pathogen enters the plant tissue, a certain gene is activated that secretes various substances,' Mardanova explained. 'This leads to tissue necrosis. The potato feels that foreign proteins have appeared. And it tries to neutralise the parasite.'

Kazan scientists managed to find out another interesting feature. The ecosystem of potato roots changes depending on the season and the age of the plant.

'We look at how the microbiota is formed, what affects it,' the expert explained. “Features and general patterns are recorded.

Strains of bacteria against Fusarium wilt

Kazan scientists are actively developing method create a biological protection of potato from Fusarium wilt.

'We have identified a number of bacillus strains that have proven active against pathogens of the dangerous fungal disease,' Mardanova said.

Preparations are created on the basis of bacillus subtilis. This type of bacteria has a huge potential. It is characterised by antagonistic activity, suppressing the growth of pathogenic bacteria and fungi.

'Biologics are absolutely harmless to humans,' said the expert. “Besides, they are eco-friendly.

The only drawback the scientist called is the short shelf life — no more than a year and a half. As a comparison: chemicals retain their properties for 5 years or more.

'The development of such drugs always contributes to import substitution,' Mardanova expressed her point of view. 'We are developing technology, gaining independence from other countries and regions.'

Domestic drugs are much cheaper than similar ones from abroad. Besides, samples are created in Tatarstan and for Tatarstan citizens. Scientists take into account all the features of the local climate and the structure of the soil.

By Yelena Simakova