Pyricularia penniseticola causing leaf spot and blast diseases on canna lily ( Canna × generalis ): Pathogen Characterization, Thermotolerance, and Fungicide Sensitivity

Pyricularia species cause destructive foliar diseases such as rice blast, leading to drastic losses in yield in a variety of agronomic and ornamental crops worldwide. Beginning summer 2021, commercial growers of canna lily (Canna × generalis) in Florida reported leaf spot and blast symptoms of the plants with up to 100% disease incidence. Canna lily samples from eleven cultivars across six counties submitted to the Gainesville Plant Diagnostic Center and the Gulf Coast Research and Education Center diagnostic lab consistently resulted in isolations of Pyricularia spp. This study reports P. penniseticola as a new pathogen of canna lily in the United States, characterized morphologically and molecularly, and assessed for pathogenicity, thermotolerance, and fungicide sensitivity. Our findings provide insight into understanding this new disease on canna lily and may inform future efforts to monitor and manage Pyricularia infections in ornamental nursery crops.