First Report of Leaf Spot of Datura metel Caused by Alternaria tenuissima in Korea

Abstract

In June 2013, we collected leaf spot disease samples of Datura metel from Gangneung, Gangwon Province, Korea. The symptoms observed were small circular to oval dark brown spots with irregular in shape or remained circular with concentric rings. We isolated the pathogen from infected leaves and cultured the fungus on potato dextrose agar. We examined the fungus morphologically and confirmed its pathogenicity according to Koch's postulates. The results of morphological examinations, pathogenicity tests, and the rDNA sequences of the internal transcribed spacer regions (ITS1 and ITS4), glycerol-3-phosphate dehydrogenase (G3PDH) and the RNA polymerase II second largest subunit (RPB2) gene sequence revealed that the causal agent was Alternaria tenuissima. To the best of our knowledge, this is the first report of leaf spot of D. metel caused by A. tenuissima in Korea as well as worldwide.

First Report of Leaf Spot Caused by Alternaria tenuissima on Black Chokeberry (Aronia melanocarpa) in Korea

“…2). These morphological characteristics were similar to features of other Alternaria species, which were reported in A. melanocarpa previously (Table 1) [456]. …”

“…A sequence of Stemphylium herbarum was selected as an outgroup (Fig. 4) [5131415]. The fungal pathogen isolated from leaf spot on Aronia melanocarpa was closely related to Alternaria tenuissima .…”