Stem Rot on <i>Datura innoxia</i> Caused by <i>Sclerotinia sclerotiorum</i> in Brazil

ABSTRACT Datura innoxia , commonly known as ‘angel's trumpet’ or ‘devil's trumpet’, is an ornamental plant widely distributed and cultivated in Brazilian gardens. However, a stem rot was observed in garden plants in Curitiba, Paraná, Brazil. This study aimed to identify the causal agent of the disease through molecular characterisation, morphological characterisation and pathogenicity testing. The isolate CMRP7504 was obtained from internal fragments of diseased stems of D. innoxia . Molecular characterisation was performed using Maximum Likelihood (ML) and Bayesian Inference (BI) analyses of concatenated partial sequences of the G3PDH and HSP60 genes, in addition to the internal transcribed spacer (ITS). The DNA sequences of the pathogen clustered into a reliable clade identified as Sclerotinia sclerotiorum . Morphological characterisation matched the descriptions for S. sclerotiorum . Pathogenicity was assessed in potted plants inoculated with mycelial plugs of the isolated causal agent. Inoculated plants began to wilt on the 13th day, did not recover, and died after the 15th day post‐inoculation. The fungus was re‐isolated from lesions of inoculated plants and showed the same morphological characteristics as isolate CMRP7504. To the best of our knowledge, this is the first report of S. sclerotiorum causing stem rot in D. innoxia plants in Brazil.