Agri Business

Scientists find a way to save wheat from stem rust disease

TV Jayan New Delhi | Updated on January 09, 2018

In a development that could give much reprieve to wheat farmers across the world, scientists have gained gene-level insights into how a deadly fungus attacks the cereal crop, leading to its widespread destruction, as seen already in many countries in Africa and West Asia.

Though the fungal epidemic caused by a strain of fungus Puccinia graminis tritici (Pgt), called Ug99, has not reached India yet, it has been lurking in the neighbourhood; in Iran and Afghanistan for a while.

The fungal strain, first detected in Uganda around 1999 (thus the name Ug99), is much dreaded because 90 per cent wheat grown all over the world could be susceptible to it. This is because it can overcome the resistance conferred by a specific gene called Sr35 which is part and parcel of the most high-yielding wheat varieties.

Now, in two studies, published in the journal Science on Thursday, scientists from Australia, the UK and the US, have developed a DNA testing technique that could identify whether the rust pathogen in a particular crop can overcome a novel rust resistance gene that is being introduced in high-yielding wheat varieties in many countries. To do this, the scientists made use of the insight they gained from the discovery of a rust virulence molecule that wheat plants detect to ‘switch on’ built-in resistance and stave off the disease.

The breakthrough would mean suspect samples could be analysed within hours in an emergency rather than weeks, potentially saving crops from being destroyed.

“For the first time it will be possible to do DNA testing to identify whether a rust in a wheat crop anywhere in the world can overcome a rust-resistance gene, called Sr50, which is being introduced in high-yielding wheat varieties,” said Robert Park, a scientist with the Plant Breeding Institute at the University of Sydney.

“This will indicate whether or not a given wheat crop needs to be sprayed with expensive fungicide quickly to protect against rust — which would otherwise devastate the crop in a matter of weeks,” he said.

The pathogen is already spreading to other parts of the world. Stem rust was spotted in wheat fields in Sweden very recently, and thus has made a comeback in Europe, said Kostya Kanyuka from Rothamsted Research, an agricultural science centre in the United Kingdom, and a co-author of the study.

Published on December 22, 2017

Follow us on Telegram, Facebook, Twitter, Instagram, YouTube and Linkedin. You can also download our Android App or IOS App.

This article is closed for comments.
Please Email the Editor