Identification and characterization of Plantago asiatica mosaic Potexvirus from Lily in Korea

다국어 초록 (Multilingual Abstract)

Plantago asiatica mosaic virus (PlAMV) is the most important virus infecting lily in the world. PlAMV is a member of the genus Potexvirus in the family Alphaflexiviridae. In Korea, Occurrence of PlAMV was surveyed at Jeju, Yesan, Taean, Gwacheon and Gangneung areas in Korea during 2012, 2013 (specimens kept NAS) and 2014, 2015 (specimens collected to this thesis). Symptoms of PlAMV were malformation and mosaic on the leaves, and mosaic, necrosis and pale browning on bulbs. the investigation of viral disease incidence on lily, multiplex primer for Cucumber mosaic virus (CMV), Lily mottle virus (LMoV), Lily symptomless virus (LSV) and PlAMV infecting lily in Korea was used. Average infection rate on the fields cultivated with the imported lily bulbs was 95.6% at 5 areas including Jeju. The total infection rate for single and mixed infection of LMoV was 75.6%. No single infection was observed for PlAMV, but total mixed infection rate of two or more viruses with PlAMV was 36.1%. In the biological characteristics, PlAMV infected locally on the plant species of Chenopodium amaranticolor, C. quinoa and Gomphrena globosa. The isolate of PlAMV from Jeju could infect systemically on Tetragonia expansa. However, other isolates of PlAMV without Jeju could not infect on T. expansa. All PlAMV isolates from five areas including Jeju could infect systemically with mosaic symptom on Nicotiana benthamiana and N.occidentalis, and infect symptomless on lily. Electron microscopy for the cells of upper leaves of N. benthamiana infected with PlAMV shown typical ultrastructure of Potexvirus for the cluster of virus particles. The Potexvirus ultrastructure was same on mesophyll and conductive cells. Phylogenetic analysis of PlAMV was done for five PlAMV isolates from lily in this thesis, and nine PlAMV isolates from lily and each of Plantago and Primrose from in NCBI database. From the full sequences, PlAMV could divide five clusters. Korean PlAMV isolates imported from Netherlands were related strongly with PlAMV from Netherlands. In amino acid analysis of PlAMV, Korean isolates were same in genetic relationship. Two isolates of PlAMV classificatied biologically on lily in Korea might have come from Netherlands and seven isolates from Japan were same in genetic relationship.

Keyword: Plantago asiatica mosaic virus, Lily, virus infection, host range, ultrastructure, genetic characterization, genetic relationship.

목차 (Table of Contents)

• ABSTRACT 1
• INTRODUCTION 4
• LITERATURE REVIEW 7
• MATERIALS AND METHODS 10
• 1. Survey 10
• 2. Host range 14
• 3. Primer design for full-sequence 15
• 4. Total RNA extraction and RT-PCR 17
• 5. Electron microscopy 18
• 5-1. Virus particle morphology 18
• 5-2. Ultrastructure 19
• 6. Sequence and phylogenetic analyses of PlAMV 20
• RESULT AND DISCUSSION 22
• 1. Survey of virus diseases on lily 22
• 2. Host range analysis 27
• 3. Electron microscopy 31
• 3-1. Virus particle morphology 31
• 3-2. Ultrastructure 32
• 4. Genetic characterization of PlAMV isolates 35
• 4-1. Genomic sequence analysis of the PlAMV isolates 35
• 4-2. CP gene relationship analyses of PlAMV isolates 37
• LITERATURE CITED 39
• ABSTRACT IN KOREAN 42
• APPENDICES 45