A team of researchers has developed a method that speeds up diagnosis of crown gall disease, which can damage or kill valuable nursery stock, berry bushes, grape vines, roses, and nut and fruit trees.
The testing procedure marks a “huge step forward” in eventually allowing growers to test for crown gall on-site, providing results in about 30 minutes, said Jeff Chang, an associate professor at Oregon State University. Now, testing takes about 2.5 hours, with growers taking or sending plants to OSU’s plant clinic for identification of diseases.
There is no cure for crown gall disease, but quicker, on-site confirmation of the pathogen’s presence will allow growers to isolate, remove and destroy infected plants, potentially halting the spread of the disease.
“They can accelerate that (detection) process and save on how many plants they have to throw away,” Chang said.
Crown gall is caused by a soil-borne bacteria called Agrobacterium tumefaciens, which enters plants through plant tissue wounds caused by such things as pruning cuts, boring insects and freeze damage. The pathogen genetically modifies plant tissue, stimulating it to produce swollen knobs called galls.
The disease can kill young plants and disfigure nursery stock to the point that it can’t be sold and must be thrown away.
The researchers, funded by a grant from USDA’s National Institute of Food and Agriculture, developed molecular tools to diagnose crown gall.
Chang and post-doctoral researcher Elizabeth Savory co-wrote a report on the study. Skylar Fuller, a recent OSU graduate, designed the detection mechanism under Chang’s and Savory’s mentorship. Other collaborators were Alexandra Weisberg, also a post-doctoral researcher, and Melodie Putnam, the plant clinic director. The team used variations of gene sequences originally developed by OSU Professor Walt Ream.