벼멸구(Nilaparvata lugens) 국내 유입 특성 규명을 위한 RNA-seq 기반 집단유전 분석 = RNA-seq–Based Population Genetic Analysis to Elucidate the Introduction Dynamics of the Brown Planthopper (Nilaparvata lugens) in Korea

다국어 초록 (Multilingual Abstract)

We assessed the population genetic structure of the brown planthopper, Nilaparvata lugens (Stål), in Korea using genome-wide SNPs derived from RNA-Seq. Adults were collected from 6 rice-growing regions in Korea in 2024. For each region, three replicate RNA samples were prepared by pooling 10 adults per replicate, resulting in 39 pooled RNA-seq libraries (totaling 390 individuals). After quality control and variant filtering, 1,254,719 high-quality SNP loci were retained for downstream analyses.
Across populations, observed heterozygosity (Ho) exceeded expected heterozygosity (He), and fixation indices (FIS) were predominantly negative, indicating a heterozygosity excess pattern at the pooled-sample level. AMOVA attributed 13.94% of the total genetic variation to differences among populations (Φ_ST = 0.139). Bayesian clustering (fastSTRUCTURE), PCA, and DAPC consistently revealed extensive admixture and weak geographic differentiation, with no apparent region-specific clustering. Pairwise FST values were generally close to zero (often negative), whereas higher differentiation was observed for comparisons involving the laboratory control versus a subset of field populations.
Overall, Korean collections showed limited population subdivision and broad sharing of genetic components across regions. Although insecticide resistance phenotypes (or resistance-associated loci) were not directly tested in this study, the observed connectivity implies that resistance-related genetic backgrounds—if present—could be broadly shared among regions, underscoring the value of coordinated, wide-area surveillance.

목차 (Table of Contents)

• 목 차
• 표 목차 8
• 그림 목차 9
• 1. 서론 10
• 2. 연구사 13
• 3. 재료 및 방법 16
• 3.1. 공시충 수집 및 RNA 추출 16
• 3.2. 라이브러리 제작 및 시퀀싱 데이터 전처리 18
• 3.3. 참조 유전체 정렬 및 SNP 변이 탐색 20
• 3.4. 집단 유전학적 통계 분석 21
• 4. 결과 23
• 4.1. 유전적 다양성 23
• 4.2. 집단 유전 구조 26
• 4.3. 주성분 분석 (PCA) 및 판별 분석 (DAPC) 28
• 4.4. 계통수 및 유전적 분화도 31
• 5. 고찰 36
• 6. 참고문헌 39
• 부록 목차 46