声明
Contents
摘要
ABSTRACT
ABBREVIATIONS
CHAPTER 1 Literature review
1．1 General introduction of the rubber tree(Hevea brasiliensis)
1．1．1 History and plant distribution
1．1．2 Global production，demand，and supply of natural rubber
1．1．3 Utilization of the rubber tree
1．1．4 Ecology and botanical characteristics
1．1．5 Propagation
1．1．6 Cultivation
1．1．7 Harvesting
1．2 Laticifer cells
1．2．1 Laticifer cells in Planta
1．2．3 Type of laticifers
1．2．4 In vitro laticifer cells
1．2．5 Laticifer cells in rubber tree
1．3 Rubber tree breeding
1．4 MADS-box gene family
1．5 Objective and significance
1．5．1 Objective
1．5．2 Significance
CHAPTER 2 Callus inductions and plant regeneration
2．1 Introduction
2．2 Materials and methods
2．2．1 Explant preparation
2．2．2 Callus induction
2．2．3 Somatic embryoid induction
2．2．4 Plant regeneration
2．2．5 Shoot induction from bud culture
2．3 Result
2．3．1 Callus induction
2．3．2 Somatic embryogenesis
2．3．3 Plant regeneration and transplanting
2．3．4 Shoot induction from axillary and apical buds
2．4 Discussion
2．4．2 Cytokinins are involved in abnormal shoot growth in shoot induction culture
2．4．3 Correlation between callus growth and latex yield may aid breeding
CHAPTER 3 Identification of laticifer cells in callus cultures of the rubber tree
3．1 Introduction
3．1．1 Laticifer cells in Planta
3．1．2 Biological functions of laticifers
3．1．3 Types of laticifers
3．1．4 In vitro laticifer cell
3．1．5 The laticifers in the rubber tree
3．2 Materials and methods
3．2．1 Plant preparations and materials
3．2．2 Observation of laticifer cells in callus
3．2．3 Observation of laticifer cells in the bark of young shoots，immature and mature barks of trunks
3．3 Results
3．3．1 Growth and development of in vitro laticifer cells derived from anther and shoot apical meristem
3．3．2 Comparison of the distribution patterns of in vivo and in vitro laticifer cells
3．3．3 Morphological comparison of the isolated in vivo and in vitro laticifer cells
3．3．4 Comparison of cell wall thickness of the in vivo and in vitro laticifer cells
3．4 Discussion
3．4．2 The in vitro laticifers in callus of rubber tree are more closely related to the secondary laticifers
CHAPTER4 Genome-wide identification，characterization of the MADS-box gene family and their involvement in laticifer development
4．1 Introduction
4．2 Materials and methods
4．2．1 Plant materials
4．2．2 Transcriptome assembly
4．2．3 Gene identification and nomenclature
4．2．4 Phylogenetic and sequence analysis
4．2．5 RNA isolation and qRT-PCR analysis
4．3 Results
4．3．1 Identification and classification of MADS-box genes in the rubber tree
4．3．2 Gene structure and conserved motif analysis
4．3．3 The MIKCc-type MADS-box genes are duplicated actively in subgroup-specific pattern and play both conserved and diverged functions
4．3．4 The MIKC*-type genes are highly duplicated in rubber tree and may have evolved both conserved and diverged biological functions
4．3．5 Type Ⅰ MADS-box transcription factor genes in the rubber tree are restricted in duplication and are mostly silent
4．4 Discussion
4．4．1 Duplication pattern of MADS-box gene family in plants
4．4．2 MIKCc-type MADS-box genes have evolved new function in regulation of laticifer development in the rubber tree
4．4．3 Typical and atypical MIKC*-type MADS-box genes in angiosperms
4．4．4 Type Ⅰ genes are mostly silent and have experienced high death rate
CHAPTER 5 Comparative analysis of in vivo and in vitro laticiferous cells and their correlation with rubber yield
5．1 Introduction
5．2 Materials and methods
5．2．1 Field cultivation of rubber tree clones and yield estimation
5．2．2 Callus induction
5．2．3 Observation and quantification of laticifer cells in callus
5．2．4 Preparation of bark samples and histochemical study
5．3 Results
5．3．1 Callus induction from young shoots of 11 varieties with different yield potential
5．3．2 Laticifer density in callus is highly correlated with the laticifer ring number in the bark
5．3．3 Laticifer densities (LD)in callus is equally correlated with rubber yields as the secondary laticifer ring number(LR)in the bark
5．4 Discussion Laticifer density(LD)in callus is a promising marker for the early selection of breeding clones with high-yield potential
CONCLUSIONS
REFERENCE
APPENDIX
ACKNOWLEDGEMENT
