Characterization of Myrothecium roridum Isolated from Imported Anthurium Plant Culture Medium

During an investigation of microorganisms and pests in plant culture media from imported anthurium pots, a fungal isolate (DUCC4002) was detected. Based on its morphological characters including colony shape on potato dextrose agar, the microstructures of spores observed by light and scanning electron microscopy and the results of phylogenetic analysis using an internal transcribed spacer rDNA sequence, the fungal isolate was identified as Myrothecium roridum. Pathogenicity testing on anthurium leaves revealed that the fungus could colonize and produce sporodochia on the inoculated leaves. This is the first report of M. roridum detected in imported plant culture medium in Korea.

First Report of Myrothecium roridum Causing Leaf and Stem Rot Disease on Peperomia quadrangularis in Korea

In 2010, symptoms of leaf and stem rot were observed on potted plants (Peperomia quadrangularis) in a greenhouse in Yongin, Korea. The causative pathogen was identified as Myrothecium roridum based on morphological data, internal transcribed spacer sequence analysis, and pathogenicity test. To our knowledge, this is the first report of M. roridum causing leaf and stem rot disease on P. quadrangularis in Korea and elsewhere worldwide.

New hosts of Myrothecium spp. in Brazil and a preliminary in vitro assay of fungicides

Myrothecium roridum and M. verrucaria are two plant pathogenic species causing foliar spots in a large number of cultivated plants. This paper aims to study the causal agents of foliar spots in vegetable crops (sweet pepper, tomato and cucumber), ornamental plants (Spathiphyllum wallisii, Solidago canadensis, Anthurium andreanum, Dieffenbachia amoena) and a solanaceous weed plant (Nicandra physaloides). Most of the isolates were identified as M. roridum; only the isolate 'Myr-02' from S. canadensis was identified as M. verrucaria. All the isolates were pathogenic to their original plant hosts and also to some other plants. Some fungicides were tested in vitro against an isolate of M. roridum and the mycelial growth recorded after seven days. Fungicides with quartenary ammonium, tebuconazole and copper were highly effective in inhibiting the mycelial growth of M. roridum. This paper confirms the first record of M. roridum causing leaf spots in sweet pepper, tomato, Spathiphyllum, Anthurium, Dieffenbachia and N. physaloides in Brazil. We also report M. roridum as causal agent of cucumber fruit rot and M. verrucaria as a pathogen of tango plants.