First occurrence of leaf blight of bird’s-nest fern, Asplenium nidus, caused by Rhizoctonia solani AG-1 IB

Abstract

A new disease of bird’s-nest fern (Asplenium nidus, cv. Emerald) with dark-green, water-soaked lesions on the leaves has been found in Fukuoka Prefecture, Japan since approximately 1996. The lesions gradually extended from the lower part of the leaves near the soil to the tip of the leaves under high humidity. Affected leaves and petioles softened, turned dark-brown and dry. When severely infected, plants had rotted petioles and withered. A causal fungus was isolated from the infected tissues, and these isolates caused the same symptoms on cvs. Abis and Emerald of bird’s-nest fern in inoculation tests. The pathogen was identified as Rhizoctonia solani based on the morphological and cultural characteristics, and the hyphal anastomosis group and the cultural type were determined as AG-1 IB, confirmed with PCR analysis using specific DNA primer sets for the anastomosis groups. The name leaf blight was proposed for this disease on bird’s-nest fern.