Species shift in the stem blight pathogen complex

Authors: Polashock, James

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Stem blight is a devastating disease of blueberry. It is important in New Jersey, other growing regions of the U.S., and other parts of the world. This disease is particularly devastating in young plantings, where entire bushes can be killed. In older plantings, whole canes are killed and if the disease reaches the crown, even mature bushes can be killed. The pathogen enters through a wound and quickly spreads downward through the vascular tissue. The first symptoms are usually seen as reddening or yellowing of the leaves on one or more shoots of an otherwise healthy plant. Stem Blight is thought to be caused by the fungus Botryosphaeria dothidea. We isolated fungi from canes with Stem blight symptoms in 2014, 2016 and 2018. The isolated fungi were identified using morphological characters and DNA sequencing data. Our data show that Stem blight is actually caused by a complex of different fungal species, not just B. dothidea as reported in the literature. In fact, the frequency of B. dothidea isolation from infected tissue is decreasing, while those of Neofusicoccum species are increasing. We also identified Phomopsis spp., Pestalotiopsis spp. and Neopestalotiopsis spp. as also causing Stem blight. Some of the species we have identified have not been previously reported in the U.S. These data represent an important prerequisite to developing effective control recommendations.