隨著世界人口的增長,人們對棉花的需求也越來越大,導(dǎo)致棉花育種工作的主要目標(biāo)是保障棉花纖維產(chǎn)量的穩(wěn)定。由于單鈴籽棉重是由多重產(chǎn)量性狀決定,因此提高棉花的產(chǎn)量是一個巨大的挑戰(zhàn)。產(chǎn)量和纖維品質(zhì)共同調(diào)控棉鈴發(fā)育。解析調(diào)控棉鈴大小農(nóng)藝性狀的遺傳和生物學(xué)機制,對棉花研究者來說仍是一個巨大的挑戰(zhàn)。為了解析其遺傳機制,一個通過種間雜交獲得的小棉鈴?fù)蛔凅wBS41,在調(diào)控單鈴籽棉重,皮棉重,百粒重等性狀表現(xiàn)出雜種衰敗。通過多重標(biāo)記的檢測,在12染色體上鑒定到了一個穩(wěn)定的調(diào)控位點,qSCW-c12。在后代BC2F4群體中,這個位點qSCW-c12在AD-A12₀7和AD-FM₄4標(biāo)記之間,大小為0.89 cM。一個主效的雜交衰敗多效性位點(qSCW-c12),其在多個連續(xù)的群體中被證實調(diào)控棉鈴的大小和產(chǎn)量性狀。通過連續(xù)的精細(xì)定位,在12號染色體上將其縮小到0.89 cM遺傳區(qū)間,與之相對應(yīng)是包含11個基因的180 Kb的物理區(qū)段。同源比對也測到了一個40個堿基插入缺失位點在AD-FM₄4克隆序列,在與SCW緊密連鎖的GhBRH1_A<...

【文章頁數(shù)】：150 頁

【學(xué)位級別】：博士

【文章目錄】：
Abstract
摘要
List of abbreviations
Chapter 01 Introduction
    1.1 Cotton taxonomy and economic importance
    1.2 Era of cotton genomics
    1.3 Genetic linkage mapping
    1.4 Bulk segregation analysis(BSA)
    1.5 Mapping populations
    1.6 Molecular markers and QTL mapping
    1.7 Mapping QTLs for complex yield traits
    1.8 Fine mapping strategies
    1.9 Fine mapping complex trait in crops
    1.10 Fine mapping and map-based cloning in cotton
    1.11 Boll development phases in cotton
    1.12 Microsatellites motif imperfection
    1.13 Mechanism of motif imperfection in SSRs
    1.14 Intrinsic DNA features relate imperfection in microsatellites
    1.15 Motif imperfection and evolution of polyploidy in crops
    1.16 Study objectives and significance
Chapter 02 Map-based cloning qSCW-cl2
    2.1 Introduction
    2.2 Materials and methods
        2.2.1 Plant materials and mapping populations
        2.2.2 Phenotype evaluation and analysis
        2.2.3 Designing markers from genomic sequences
        2.2.4 PCR, PAGE and SSR genotyping
        2.2.5 Genetic map construction and QTL mapping
        2.2.6 Regional association mapping
        2.2.7 Scanning electron microscopy (SEM)
        2.2.8 Ovule culture assay
        2.2.9 Measurement of total fiber units (TFU)
        2.2.10 Gene annotations prediction
        2.2.11 Digital expression analysis in Li₁ transcriptome
        2.2.12 RNA extraction and real-time PCR
        2.2.13 Cloning for structural variations in GhBRH1_A12
        2.2.14 Shoot elongation and BL sensitivity assay
        2.2.15 Histological analysis
    2.3 Results
        2.3.1 Boll size variations between Emian22 and BS41
        2.3.2 Phenotypic analysis of boll weight traits
        2.3.3 Detecting yield trait QTLs on chr12
        2.3.4 qSCW-c12 identification, validation in different populations
        2.3.7 Fine mapping qSCW-c12
        2.3.8 Refine mapping qSCW-c12
        2.3.9 Homology mapping and candidate gene prediction
        2.3.10 Map-based cloning qSCW-c12
        2.3.11 Candidate gene prediction based on their expression
        2.3.12 GhBRH1_A12 was differentially expressed in ODPA ovules
        2.3.13 GhBRH1_A12 involved in modulating BR homeostasis
        2.3.14 BS41 exhibited BR-deficient mutant like phenotype
        2.3.15 BS41, a novel BR-insensitive mutant
        2.3.16 BR insensitivity attenuated cell expansion in BS41
        2.3.17 BS41 features quality fiber production
    2.4 Discussion
        2.4.1 BILs are valuable resource for fine mapping QTLs
        2.4.2 Boll size regulating QTLs on chr12
        2.4.3 qSCW-c12 interval consistent with previously mapped QTLs
        2.4.4 GhBRH_A12, a new player in regulating Fiber initiation
        2.4.5 QTL qSCW-c12 is a pleiotropic locus
        2.4.6 GhBRH1_A12 involved in modulating BR homeostasis
        2.4.7 BS41, a novel boll size mutant producing quality fiber
    2.5 Conclusion
Chapter 03 Functional analysis of BRH1 gene family in cotton
    3.1 Introduction
    3.2 Material and methods
        3.2.1 Sequence retrieval, gene structure, and phylogenetic analysis
        3.2.2 Protein domain, motif, annotation, and GO analysis
        3.2.3 Prediction of transmembrane topology
        3.2.4 Expression profiling
        3.2.5 Digital expression analysis in Li₁ transcriptome
        3.2.6 Cloning for structural variations in GhBRH1_A12
        3.2.7 Constructing overexpression vectors
        3.2.8 RNAi vector construction
        3.2.9 Genetic transformation and cotton tissue culture
        3.2.10 RNA extraction and qRT-PCR
        3.2.11 Phenotype evaluation and analysis
    3.3 Results
        3.3.1 Structure of BRH1 peptide
        3.3.2 Identification of putative BRH1 genes in four cotton genomes
        3.3.3 Phylogenetic analysis of cotton BRH1 genes
        3.3.4 Genetic diversity and evolution of GhBRH1 gene family
        3.3.5 Characteristics of GhBRH1 gene family
        3.3.6 Expression profiling of GhBRH1 genes in cultivated cotton
        3.3.7 GhBRH1 differentially expressed during fiber development
        3.3.8 Gene regulatory elements of GhBRH1_A12 in BS41
        3.3.9 Genetic transformation of a GhBRH1_A12 in cotton
        3.3.10 GhBRH1_A12 expression in transgenic (T₀) plants
    3.4 Discussion
Chapter 04 Evolutionary dynamics of motif imperfection in cotton
    4.1 Introduction
    4.2 Material and methods
        4.2.1 Genome assemblies of 13 plant species
        4.2.2 Imperfect microsatellites identification
        4.2.3 Motif Imperfection and repeat length analyses
        4.2.4 Transposable elements (TEs)distribution
        4.2.5 Motif imperfection in coding region of Gossypium species
        4.2.6 Microsatellites conservation analysis
        4.2.7 Microsatellite loss during paleopolyploidization event
    4.3 Results
        4.3.1 Frequency and distribution of microsatellites
        4.3.2 Motif imperfection and repeat length relationship
        4.3.3 Motif imperfection in Gossypium genomes
        4.3.4 Motif interruptions in coding sequence
        4.3.5 Large motif repeats well conserved in Gossypium species
        4.3.6 Microsatellite decay estimation
        4.3.7 Biased distribution of 2nt repeats in Gossypium species
    4.4 Discussion
    4.5 Conclusion
References
Supplementary information
Publications
Acknowledgement
附件



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