Seedlings at Rutgers Inoculated With EFB

Today at Rutgers University, thousands of hazelnut seedlings are being inoculated with spores of the fungus Anisogramma anomala to test their resistance to eastern filbert blight.

The inoculation procedure begins with cutting the stromata (mushroom-like fruiting bodies) from infected stems. 

Next, the stromata are ground up in distilled water with a mortar and pestle to release the millions of spores they contain. This spore solution is then diluted to a specific concentration shown to work best with young hazelnut seedlings. 

The spore solution is sprayed directly onto the growing tips of plants, which are grown in humidity chambers that mimic the conditions that occur in nature during infection.

John Capik sprays seedlings in the inoculation

chamber with the spore solution.

  

From this point on, it’s a waiting game. Believe it or not, this fungus can take up to 16 months to show its devastating effects.  

The plants are raised normally after inoculations and even the susceptible ones (unknown at the time) grow well. By the end of the summer, the plants typically reach 6-8 feet tall. From here, they’re overwintered in a cold greenhouse for chilling. Proper winter chilling is necessary for the plants to leaf out and begin growing normally in the spring as well as to trigger the fungus to create the EFB cankers. They wake up and start growing the following March. It’s not until June or July that the EFB cankers become apparent and we can identify those that appear to be resistant to the disease.

These seedlings were inoculated last year, and

now we're waiting to see if cankers emerge

on the stems.

We discard the sick plants and plant the apparently healthy ones in the field in October, which grow for five more years. At the end of this time, those that show no eastern filbert blight are evaluated for the nuts they produce. – Dr. Tom Molnar, Rutgers University