First report of Fusarium concentricum causing fruit blotch on roselle (Hibiscus sabdariffa)

Abstract

Symptoms of fruit blotch were noticed on roselle (Hibiscus sabdariffa) in Relau, Penang and Karangan, Kedah. The aims of this study were to isolate and identify the suspected causal pathogen and to evaluate its pathogenicity towards the host. Two isolates of Fusarium sp. were isolated from the blotched fruits of H. sabdariffa and morphologically identified. Sequences analysis based on translation elongation factor (TEF1-α) and mitochondrial small subunit ribosomal DNA (mtSSU rDNA) showed that both isolates had 99.53% identity to AF333934 and 100% to AF333941, Fusarium concentricum. Phylogenetic analysis demonstrated that both isolates were in the same clade with the reference isolates of F. concentricum from GenBank, supported by 97% bootstrap value. The isolates were pathogenic toward H. sabdariffa, exhibiting typical blotch symptoms on the inoculated fruits. This is the first report of fruit blotch disease caused by F. concentricum on H. sabdariffa in Malaysia.