Fire blight costs the U.S. apple industry an estimated $100 million annually in crop losses. New research from Cornell AgriTech may help apple breeders develop resistant varieties and give growers a more sustainable solution in managing the disease.
Caused by the bacterium Erwinia amylovora, fire blight infects apple trees through flowers or other natural openings, often facilitated by insect transmission.
“It can kill the trees – wipe out an orchard – within a few weeks,” said Awais Khan, professor at the School of Integrative Plant Science based at Cornell AgriTech. “Trees infected by the disease have blackened leaves and a scorched appearance, giving fire blight its name.”
Khan and his team conducted genetic mapping of Malus sieversii – the wild species found in the Tian Shan mountains of Central Asia from which domesticated apples originate – to identify specific genomic regions linked to fire blight resistance. They then developed DNA markers that enable them to screen apple seedlings for fire blight resistance.
Their paper, “Identification and Marker Development of a Moderate Effect Fire Blight Resistance QTL in M. sieversii, the Primary Progenitor of Domesticated Apples,” explains the mapping process and findings. Richard Tegtmeier, Ph.D. candidate in Khan’s lab is the lead author on the paper. The research was funded by the New York State Department of Agriculture and Markets’ Apple Research and Development Program.
The trees used for the research are a cross between the wild M. sieversii and Royal Gala, an apple cultivar that is highly susceptible to fire blight. The M. sieversii used in the cross were grown from the seeds and samples of the wild species collected by the scientists at Cornell during their expeditions to Central Asia in 1990s. These trees were planted at the USDA-ARS Plant Genetic Resources Unit (PGRU) in Geneva, NY.
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Categories: New York, Crops, Fruits and Vegetables