Phytoplasma has been newly detected in Elaeocarpus sylvestris, a tree species that grows on the island of Jeju, South Korea. Various symptoms of infection of E. sylvestris have appeared since 2013, including loss of leaf coloration, such as yellowing, darkening and branch dieback. We analyzed leaves and seeds of E. sylvestris sequences infected by phytoplasma, and found partial 16S rRNA sequences to be 99.5%, and secA genes 98.2% correlated with Malaysian periwinkle virescence group strain ELY-BN1, MaPV, MOP, MYD, and TtWB. Analyzing these sequences and through the virtual restriction fragment length polymorphism (virtual-RFLP), we report here the first occurrence of Elaeocarpus decline associated with a phytoplasma strain belonging to 16SXXXII groups, as well as the first detection of phytoplasma in the seeds of E. sylvestris in South Korea.

In May 2024, a disease resembling felt disease was observed on the stems and branches of Phyllostachys reticulata, with brown coloration appearing on the infected areas, and samples were collected in Byeongbawi Rock and its surroundings, Gochang-gun, Jeonbuk-do. Phylogenetic analysis was performed based on internal transcribed spacer rDNA sequences obtained from the basidiomata. This fungus was classified as Septobasidium sp., showing 97.84% similarity to the Septobasidium sp. strain isolated from the Schisandra chinensis tree. The structural characteristics of the layers of mycelia mat were compared through detailed microscopic examination. Interestingly, while the mats layer structure for commonly known blight diseases are typically single-layered, the basidiomata observed on P. reticulata exhibited a 1 to 3 layered structure. This study represents the first record of felt disease on P. reticulata in Korea, providing a comprehensive report on its morphological and molecular characteristics.

Elaeocarpus sylvestris (Lour.) Poir. var. ellipticus (Thunb.) H.Hara, an evergreen tree species native to Jeju Island, South Korea, has experienced a progressive decline associated with phytoplasma infection. This study aimed to evaluate the efficacy of oxytetracycline-based tree injection for suppressing phytoplasma and improving tree vitality. Two formulations—oxytetracycline hydrochloride (4.3%) and oxytetracycline calcium alkyltrimethyl ammonium (17%)—were administered to 40 infected individuals across two sites using a gravity-fed injection system. Treatment efficacy was evaluated based on chlorophyll content as an indicator of physiological recovery, while phytoplasma presence was assessed by PCR at 150 days after injection. The oxytetracycline hydrochloride group showed the highest suppression, with a 70% phytoplasma non-detection rate as determined by PCR analysis. Treated trees exhibited significantly higher chlorophyll content compared to untreated infected controls. These findings suggest that minimally invasive tree injection using oxytetracycline can provide temporary suppression of phytoplasma and support physiological recovery in E. sylvestris.