红棕象甲的肠道菌群结构及其对宿主营养代谢的影响

发布时间：2025-05-01 12:20

　　红棕象甲是一种入侵我国并已对世界各地棕榈产业造成巨大经济损失的毁灭性害虫。该害虫为害隐蔽以及抗药性的出现使得传统防治措施收效甚微。肠道菌群与昆虫的生长发育、免疫防御及寄主利用等关键生理过程密切相关。已有研究发现,红棕象甲的幼虫肠道内栖居着可能具有发酵代谢作用的菌群。然而,尚无直接证据证实肠道菌群在该害虫入侵扩散过程中的生理作用。为此,本文采用基于细菌16S rRNA高通量测序技术与传统培养分离技术相结合的方法比较研究了不同发育阶段红棕象甲的肠道菌群结构,然后采用抗生素饲喂的方法扰乱该害虫的固有肠道菌群稳态以评价肠道菌群对宿主的生理贡献。研究发现,不同发育阶段红棕象甲的肠道菌群中90%以上的细菌隶属于变形菌门和厚壁菌门。从科级分类水平来看,约60%的细菌属于肠杆菌科,然后依次是乳酸杆菌科、Entomoplasmataceae、Commonadaceae、肠球菌科、链球菌科和Rhodobacteraceae。在不同发育阶段的红棕象甲肠道中,这些不同科的细菌所占比例明显不同。另外,雌虫肠道菌群中肠杆菌科的相对含量为87%,明显高于雄虫肠道中肠杆菌科细菌的相对含量(41.23%)。不同地理来源的...

【文章页数】：161 页

【学位级别】：硕士

【文章目录】：
摘要
Abstract
ACKNOWLEDGEMENTS
Chapter 1 GENERAL INTRODUCTION
    1.1. Background of Red Palm Weevil
    1.2. Importance of gut microbiota
    1.3. The functions of gut microbiota
        1.3.1. Providing protection against the pathogen
        1.3.2. Improving host performance
        1.3.3. Digestion and degradation
        1.3.4. Nutritional responses
    1.4. Variation of gut microbiota
    1.5. RPW associated microbiota deduced roles
    1.6. Research hypotheses and objectives
Chapter 2 DIVERSITY OF CULTIVABLE BACTERIA IN THE GUT OF RHYNCHOPHORUS FERRUGINEUS LARVAE
    2.1. Introduction
    2.2. Materials and methods
        2.2.1. Insect collection
        2.2.2. Gut dissection
        2.2.3. Isolation of RPW Cultivable Gut microbiota
        2.2.4. Molecular characterization of the isolates
        2.2.5. Phylogenetic Analysis
        2.2.6. Biochemical characterization of Cultivable bacteria
    2.3. Results
        2.3.1. Molecular characterization
        2.3.2. Biochemical chemical characterization
    2.4. Discussion
    2.5. Conclusions
Chapter 3 COMPLEXITY AND VARIABILITY OF THE GUT MICROBIOTA AT VARIOUS LIFE STAGES OFRHYNCHOPHORUS FERRUGINEUS
    3.1. Introduction
    3.2. Materials and Methods
        3.2.1. Insect sampling and maintenance
        3.2.2. Gut dissection
        3.2.3. DNA extraction
        3.2.4. Amplicon Generation
        3.2.5. Library Preparation and Sequencing
        3.2.6. Paired-end (PE) reads assembly and quality control
        3.2.7. OTUs cluster and Species annotation
        3.2.8. Alpha (α) diversity
        3.2.9. Beta (β) diversity
        3.2.10. Statistical analysis
    3.3. Results
        3.3.1. Prevalence of gut microbiota in various life stages
        3.3.2. Prevalence of gut microbiota in adult male and female RPW
        3.3.3. Prevalence of gut microbiota in field collected (HL, LL, and PL) and lab-reared larvae of RPW
    3.4. Discussion
    3.5. Conclusion
Chapter 4 EFFECTS OF DYSBIOSIS ON HOST NUTRITION ENERGY ALLOCATION
    4.1. Introduction
    4.2. Materials and Methods
        4.2.1. Insect Collection and Maintenance
        4.2.2. Antibiotic treatment
        4.2.3. Establishment of the culture for nutritional indices assay
        4.2.4. Hemolymph Extraction
        4.2.5. Determination of Protein Concentration
        4.2.6. Determination of Glucose Concentration
        4.2.7. Determination of Triglyceride (TG) concentration
        4.2.8. Effects of antibiotic on Gut microbiota
        4.2.9. Statistical analysis
    4.3. Results
        4.3.1. Effect of antibiotic treatment on hemolymph Protein, Glucose, and Triglyceride (TG) contents
        4.3.2. Taxonomic composition and diversity of RPW gut microbiota
    4.4. Discussion
    4.5. Conclusion
References
Appendices
    Appendix Ⅰ
    Appendix Ⅱ



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