First Report of Leptosphaerulina saccharicola Isolated from Persimmon (Diospyros kaki ) Tree Bark in Korea

Abstract

A fungal strain, designated PTT-2, was isolated from the bark of the trunk of a persimmon (Diospyros kaki) tree in Cheongdo, Korea. The isolate showed morphological similarities with Leptosphaerulina saccharicola. Strain PTT-2 had more rapid growth on potato dextrose agar medium than on oatmeal agar, malt extract agar, and synthetic nutrient poor agar media, with colony sizes of 53.8 mm, 49.8 mm, 48.4 mm, and 28.1 mm after 7 days at 25℃ temperature, respectively. Strain PTT-2 produced ascospores, which had irregular wavy edges, oblong to ellipsoidal shape, hyaline appearance and 23.6 × 10 μm size. The black ascomata were developed on PDA medium, and asci were recorded. A BLAST search of the internal transcribed spacer (ITS) region, TEF1-α and RPB2 gene sequences revealed that strain PTT-2 showed more than 99% nucleotide similarity with a strain of Leptosphaerulina saccharicola previously reported from Thailand. A neighbor-joining phylogenetic tree was constructed by concatenating the above-mentioned sequences, and showed that strain PTT-2 clustered in the same clade with L. saccharicola. Based on these findings, this is the first record of Leptosphaerulina saccharicola occurring in Korea.