Emergence of two new fungal diseases on tall fescue in Georgia

Harshita Saxena, Morgan J. Willis, W. Turner Spratling John W. Bagwell, C. Brian Vermeer, Alfredo D. Martinez-Espinoza, Paul L. Raymer, Bochra A. Bahri

ABSTRACT SUMMARY

Two novel disease symptoms in a tall fescue (Festuca arundinacea Shreb.) breeding nursery were observed at the University of Georgia, Griffin campus. Symptoms on leaf blades included reddish brown lesions and dark purple lesions, characteristic of anthracnose and Nigrospora blight diseases, respectively. Microscopic examination showed characteristic conidia morphology of anthracnose and Nigrospora blight, and genetic analysis revealed 98-100% and 82.7-99.8% similarity with Colletotrichum graminicola which causes anthracnose, and Nigrospora sphaerica which causes Nigrospora blight, respectively. Pathogenicity tests were conducted to confirm the Koch’s postulate. Plants displayed symptoms analogous to those found in the original field samples for anthracnose; however, Nigrospora blight still requires further validation.

Keywords: Tall fescue, anthracnose, Colletotrichum graminicola, Nigrospora blight, Nigrospora sphaerica

Read More: https://bahrilab.caes.uga.edu/files/2022/08/20574_Saxena.pdf