Morphology and Molecular Characterization of Alternaria argyranthemi on Chrysanthemum coronarium in China

Chrysanthemum coronarium is an economically important plant in Asia, and used medicinally, ornamentally and as a vegetable. In April 2017, leaf spot disease on C. coronarium was observed in Shiyan, Hubei, China. A single-spore isolate was obtained and identified based on morphology and sequence analysis using four regions (rDNA ITS, GAPDH, EF-1α, and RPB2). The results indicated that the fungus is Alternaria argyranthemi. The pathogenicity tests revealed that the species could cause severe leaf spot and blight disease on the host. This is the first report of leaf spot disease on C. coronarium caused by A. argyranthemi in the world, which is also a new record of Alternaria species in China.

Identification and Characterization of Pseudocercospora pyricola Causing Leaf Spots on Aronia melanocarpa

Leaf spot disease on black chokeberry (Aronia melanocarpa) was observed at several locations in Korea during 2014–2015. Leaf spots were distinct, scattered over the leaf surface and along the leaf border, subcircular to irregular and brown surrounded by a distinct dark color, and were expanded and coalesced into irregularly shaped lesions. Severely infected leaves became dry and fell off eventually. The causative agent was identified as Pseudocercospora pyricola. Morphological observations and phylogenetic analyses of multiple genes, including internal transcribed spacer, translation elongation factor 1-alpha, actin, and the large subunit ribosomal DNA were conducted. The pathogenicity test was conducted twice yielding similar results, fulfilling Koch's postulates. To our knowledge, this is the first report on P. pyricola infection of A. melanocarpa globally.

Identification and Characterization of Cercospora malayensis Causing Leaf Spot on Kenaf

In September 2013 and 2014, a significant number of kenaf plants showing symptoms of leaf spots with approximately 50% incidence were found in experimental plots in Iksan and Namwon, Korea. Leaf spots were circular to irregular, more or less vein-limited, reaching to 10 mm in diameter. The spots were initially uniformly brown to reddish brown, turning pale brown with a purplish margin and showing grayish patches on the lesion due to heavy fructification. The causative agent of the leaf spot disease was identified as Cercospora malayensis. The pathogenicity test was conducted with similar results, which fulfilled Koch's postulates. This is the first report of C. malayensis infection of kenaf in Korea.

Characterization of Paecilomyces variotii and Talaromyces amestolkiae in Korea Based on the Morphological Characteristics and Multigene Phylogenetic Analyses

During fungal diversity surveys of the order Eurotiales in Korea, two fungal strains, EML-DG33-1 and EML-NCP50, were isolated from samples of rat dung and fig tree leaf collected at a garden located in Gwangju in 2014. To complete the National Species List of Korea, it is a prerequisite to verify whether many questionable species, which were previously recorded but not confirmed, indeed present in Korea. Herein, the isolates were confirmed as undescribed species, Paecilomyces variotii and Talaromyces amestolkiae based on the combination of morphological and phylogenetic analyses of multigenes including the rDNA internal transcribed spacer, β-tubulin, and RNA polymerase II subunit 2.