The highly-prized resource was obtained through a collaboration with Queensland Alliance for Agriculture and Food Innovation (QAAFI) researcher Dr Lee Hickey, who had received the wheat collection from the N.I. Vavilov Institute of Plant Genetic Resources in Russia.
Vavilov, who we’ll get to know even better further on, was a prominent Russian and Soviet agronomist, botanist and geneticist best known for having identified the centres of origin, or diversity, of cultivated plants. Having grown up in a poor rural village plagued by crop failures, it’s believed he became obsessed with ending famine from an early age, and dedicated his life to the study and improvement of staple crops such as wheat, corn and other cereal crops.
Vavilov’s passion lives on today in research centres such as the CCDM, where we’re working to help reduce the economic impact of yield losses to Australian crops caused by diseases, by finding ways to increase the genetic resistance to disease among new crop varieties.
Molecular studies of pathogens that cause disease in wheat can be used to develop tools to help breeders identify wheat varieties with improved disease resistance.
CCDM’s collaborative study with Dr Hickey involved screening various genetic wheat mapping resources for sensitivity to the disease septoria nodorum blotch (SNB) of wheat. These wheat mapping resources are valuable to researchers because they are diverse and provide genetic information on particular traits and diseases that may not be evident in other populations.
SNB is a foliar disease responsible for significant yield losses in many wheat-growing areas around the world and even the best locally available modern wheat varieties in Western Australia possess only partial resistance to SNB.
A key part of the CCDM’s work is to look for sources of strong resistance among more diverse collections of germplasm, like the Vavilov collection, so that breeders can then look to introduce new traits into modern wheat varieties.
The genetic diversity of the Vavilov collection is also helping our researchers make highly detailed investigations into the genes responsible for SNB of wheat, and to learn more about how the fungus that causes SNB is able to infect its host.
SNB is caused by the pathogen Parastagonospora nodorum which is known to secrete fungal effectors to incapacitate the plant leading to cell death and the development of the disease.
In studying the Vavilov collection, CCDM researchers found that Vavilov wheats are a good source of SNB resistance. These include lines that are insensitive to the known main fungal effectors in pathogens responsible for causing SNB.
Importantly, they also uncovered novel – or new – genetic factors in Vavilov wheats that are linked to SNB resistance A build-up or accumulation of these factors can further improve resistance to this costly disease.
It’s hoped these findings will help CCDM researchers develop new tools to improve resistance to SNB and protect the Australian wheat industry from the estimated $108 million* a year in yield losses caused by it.
The CCDM also used the Vavilov collection to look for resistance to other diseases costly to the Australian wheat industry, such as tan (or yellow) spot in wheat. This study identified a high level of variation in sensitivity to tan spot among the Vavilov collection and strong positive correlation between seedling tan spot severity and sensitivity to the fungal effector ToxA. Vavilov lines that displayed high levels of adult-plant resistance to tan spot were also identified.
With tan spot responsible for estimated wheat yield losses of an $212 million* a year and control measures costing an estimated $463 million* a year, researchers are hopeful this new information will pave the way for better understanding of why particular genes are associated with sources of resistance, and in turn help refine their development of genetic markers associated with these diseases.
The CCDM is continuing to screen for SNB and tan spot susceptibility, including through the testing of the Vavilov collection, and pursuing opportunities for further national and international research collaborations as they become available.
So what more do we know about the man whose passion for combatting crop disease many years ago produced such a valuable source of research material for scientists today?
History shows us that Vavilov’s opposing theories in genetics got him in hot water with former Soviet leader Joseph Stalin’s favoured scientist Trofim Lysenko and eventually the ‘man of steel’ himself.
Vavilov became a target for Stalin and was sentenced to death in July 1941. Although the sentence was commuted to 20 years imprisonment, Vavilov tragically died in prison after just two years. Ironically, his death was caused by malnutrition, or starvation, the very condition he had dedicated his life to preventing.
Vavilov’s death sentence was posthumously overturned in 1955 as part of a review of Stalin-era death sentences, and he was later hailed a hero of Soviet science.
Today Vavilov’s name is borne not only by Russia’s Institute of Plant Genetic Resources but also its Society of Geneticists and Breeders, Institute of General of the Academy of Sciences, Institute of Plant Industry, and the Saratov Agricultural Institute.
It’s nice to know that while Vavilov’s thinking at the time brought about his demise, his legacy lives on.
If you’d like a more in-depth look at how the Vavilov findings are being put to use by the CCDM, in partnership with Dr Lee Hickey, you can read the full the paper, “Novel sources of resistance to Septoria nodorum blotch in the Vavilov wheat collection identified by genome-wide association studies”, published in the journal Theoretical Applied Genetics.