감나무속(Diospyros spp.) 점무늬병 관련 Pseudocercospora 종의 형태 및 분자 계통학적 연구 = Morphology and Molecular Phylogeny of Pseudocercospora species Associated with Leaf Spot Disease on Diospyros spp. in Korea

다국어 초록 (Multilingual Abstract)

This study investigated the morphological and phylogenetic diversity of Pseudocercospora species causing leaf spot on Diospyros kaki and D. lotus in Korea. This disease causes premature defoliation, significantly reducing both fruit yield and quality. Nineteen isolates were collected from various regions in Korea and analyzed using a four-locus dataset (ITS, actA, tef1, and rpb2). Phylogenetic results revealed high genetic diversity, with isolates forming at least two distinct monophyletic clades. The first group (JBNU-F0529, F0221, and F0595) was close to P. fuliginosa, though its exact classification is still uncertain due to moderate support. The second group (JBNU-F0479) clustered with P. dalbergiae but showed different cultural traits, such as colony color and growth rate. Notably, genetic differences between D. lotus and D. kaki isolates suggest host-specific evolution. Significant morphological variation was also observed, even among isolates from the same host. These results highlight the extensive diversity of Pseudocercospora on Diospyros in Korea, providing essential data for accurate identification and targeted disease management.

목차 (Table of Contents)

• List of tables & figures ⅲ
• List of abbreviations ⅳ
• ABSTRACT ⅵ
• 1. Introduction 1
• 1.1. Research Background: Economic Importance of Diospyros sp. 1
• 1.1.1. Ecological Diversity and Resource Value 1
• 1.1.2. Major Species 1
• 1.1.3. Significant Agronomic and Economic Impacts of Leaf Spot Disease 1
• 1.2. The Genus Pseudocercospora 2
• 1.2.1. Complex Evolutionary History of Pathogen Classification 2
• 1.2.2. Conflicts in Molecular Phylogenetic Analysis and the Ambiguity of the 'Complex' 2
• 1.2.3. Limitations of Global Surveys and the Deficiency of East Asian Data 2
• 1.3. Objectives and Originality of the Study 3
• 1.3.1. Research Goals and Integrated Methodology 3
• 1.3.2. Academic Impact and Significance of Practical Application 3
• 2. Materials and Methods 4
• 2.1. Sequence Acquisition 4
• 2.1.1. Specimen Collection 4
• 2.1.2. Morphological Observations 4
• 2.1.3. Fungal Isolation 6
• 2.1.4. DNA Extraction 6
• 2.1.5. PCR Amplification 6
• 2.1.6. Electrophoresis 8
• 2.2. Phylogenetic Analyses 8
• 2.2.1. DNA Sequencing and Phylogenetic Datasets 8
• 2.2.2. Multi-method Phylogenetic Tree Construction 9
• 3. Results 10
• 3.1. Molecular Phylogeny 10
• 3.2. Morphological Characteristics 15
• 3.2.1. P. fuliginosa-related Group Based on 4-loci Analysis : JBNU-F0529 (including F0221 and F0595) 15
• 3.2.2. Taxonomic Consideration of the P. dalbergiae-like Isolate JBNU-F047 17
• 3.2.3. A Leaf Spot Disease Caused by Pseudocercospora sp. on Diospyros lotus (JBNU-F0520) 19
• 3.2.4. Comparison of Pseudocercospora Species Associated with Leaf Spots on Diospyros lotus 21
• 3.2.5. Morphological Comparison of Pseudocercospora sp. Isolates from Diospyros kaki and D. lotus 23
• 3.2.6. Comparison of Cultural Characteristics among Isolates from Diospyros spp. 25
• 4. Discussion 27
• 4.1. Identification of Pseudocercospora Isolates 27
• 4.2. Considerations for Phylogenetic Tree Construction 27
• 4.3. Morphological and Genetic Diversity of Pseudocercospora Species 28
• 4.4. Limitations and Future Perspectives 28
• 5. Conclusion 29
• 6. References 30