First Report of Rhytisma sp. Associated with Tar Spots on Ilex cornuta

Bok-Nam  Jung1   Ji-Hyun  Park1,*   Sang-Hyun  Lee1   Hyeon-Dong   Shin2   

1Division of Forest Insect Pests and Diseases, National Institute of Forest Science, Seoul 02455, Korea
2Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea

Abstract

Tar spots have been observed on Ilex cornuta in Korea since 2015. Based on morphological and molecular analyses, the fungus responsible was determined to be a Rhytisma species, with characteristics similar to R. ilicis-latifoliae observed on Ilex latifolia from Japan. Herein, we document the first report of Rhytisma sp. on I. cornuta.

Figures & Tables

Fig. 1. Tar spots of infected with a sp. A, tar spots on an adaxial leaf surface and a herbaceous stem in May 2019; B, ascostromata developing on the amphigenous surface of living leaves, surrounded by a yellow halo; C, ascostroma on the abaxial leaf surface, exposing a yellow (arrow head); D, vertical section of ascomata; E, hymenial layer of an ascoma; F, asci with ascospores; G-I, ascospores. abs, abaxial leaf surface; ol, outer layer of stroma; uw, upper wall of ascoma; hy, hymenium; as, ascus; pa, paraphysis.