The occurrence of southern blight on Allium hookeri caused by Sclerotium rolfsii in Korea

Abstract

In July 2014, an occurrence of southern blight was observed on hooker chives (Allium hookeri) grown in Hamyang, South Korea. The typical symptoms included blighting and rotting, and severely infected plants eventually died. White mycelial mats spread over the infected hooker chives bulbs and sclerotia formed near the soil surface. DNA sequencing and phylogenetic analysis of the internal transcribed spacer rRNA gene region confirmed that the isolates were S. rolfsii. Koch's postulates were supported by pathogenicity tests conducted on healthy plants. Based on the morphological characteristics, pathogenicity tests on host plants, and molecular identification, the causal fungus was identified as S. rolfsii Saccardo. This is the first report of southern blight caused by S. rolfsii on hooker chives in South Korea.