Isolation of Exobasidium vexans from the Lesions of Blister Blight of Tea and the Prevalence of Anamorphic Structures in Culture

Abstract

Tissue isolation was attempted with lesions of blister blight of tea to obtain colonies of Exobasidium vexans. After the ordinary surface sterilization method, colonies of E. vexans emerged from 13 leaf pieces in 180 leaf pieces examined (8.1%) collected in the Ashigara area, Kanagawa, Japan, on calcium–amended PDA. Fungal contamination occurred on 56.9% of the leaf pieces. Colony morphology of the tissue isolates was the same as that obtained from a mass basidiospore isolation. Colonies were composed of pseudohyphae and blastospores and gradually transformed to chlamydospore-like bodies (CLB) after 5 months. Germinability of CLB was tested by spreading a colony suspension on calcium–amended PDA. After 10 days incubation, CLB germinated and produced blastospores. Four germination types of CLB were categorized.