Identification of Erysiphe izuensis on Rhododendron yedoense f. poukhanense in Korea Based on Morphological and Molecular Characteristics

Sung-Eun Cho1   Sang-Hyun Lee2   Sun-Keun Lee2   Sang-Tae Seo2   Hyeon-Dong Shin1,*   

1Division of Environmental Science and Ecological Engineering, Korea University
2Forest Insect Pests and Diseases Division, National Institute of Forest Science

Abstract

The Rhododendron powdery mildew fungus Erysiphe izuensis has been recorded throughout Asia, including China, Japan, Korea, and Russia. In Korea, E. izuensis has been identified based on morphological characteristics of the anamorph found on introduced Rhododendron spp. We here describe the first identification of E. izuensis collected from Rhododendron yedoense f. poukhanense in Korea. Morphological characteristics of the teleomorph as well as internal transcribed spacer sequences of the species are provided. Moreover, we describe the characteristics of the primary conidia and conidial surface pattern of E. izuensis for the first time.

Acknowledgements

This work was financially supported by a grant from the National Institute of Forest Science. Additional funding was received by the BK21 Plus program in 2016~2020 funded by the National Research Foundation of Korea (NRF) and also in part by a special grant from Korea University to HDS.

Figures & Tables

Fig. 1. Erysiphe izuensis on Rhododendron yedoense f. poukhanense. A, symptoms on abaxial and adaxial leaf surface; B, formation of chasmothecia on abaxial leaf surface; C, hypha with lobed appressoria; D, E, conidiophores; F, primary conidium; G, conidia; H, germinating conidium; I, conidium showing the angular/rectangular pattern of outer wall; J, chasmothecium; K, chasmothecial appendages; L, ascus.