声明
摘要
Abstract
TABLE OF CONTENTS
ABBREVIATION
CHAPTER 1 General Introduction
1．1 Introduction
1．1．1 Research aims and objectives
1．2 Literature review
1．2．1 Rice environments and cropping systems
1．2．2 Rice domestication and classification
1．2．3 Evolution of grain yield improvement in rice
1．2．4 The current understanding of the genetic and molecular controls of grain yield in rice
1．2．5 Breeding strategies to break the glass ceiling of grain yield
1．2．6 Influence of functional genomic tools on plant breeding for crop improvement
1．2．7 Breeding for high yield and multiple stress tolerance
1．2．8 Trends in Rice production across the world
1．3．Scope and outline of the thesis
CHAPTER 2 Methodology
2．1 Introduction
2．3 Source of breeding materials
2．4 Characteristics of target population environment(TPE)
2．5 Screening for drought tolerance and RYMV resistance in target population environment
2．5 Progeny testing experiments
2．6 Screening for WTR1 Introgession lines for resistance to RYMV
2．7 Genotyping of the WTR1 ILs
CHAPTER 3 Genetic Variability，trait Heritability，Associations，and Path Coefficient Analysis on Yield and Yield component traits
3．1 Introduction
3．2 Methodology
3．2．1 Study materials
3．2．2 Methods
3．2．3 Data analysis
3．3 Results and discussion
3．3．1 Genetic variation and Performance of the 65 ILs under WTR1 background
3．3．2 Genetic variation and phenotypic characteristics of the yield component traits
3．3．3 Heritability of the yield component traits under variable water regimes
3．3．4 Association between high grain yield and yield component traits under variable water regimes
3．3．5 Path coefficient analysis for direct and indirect effects of nine yield component traits on grain yield
3．3．6 Selection of promising ILs
3．3．7 Pyramid crosses of the WTR1 ILs for high grain yield and multiple trait tolerance
3．3．8 screening of F2 progeny for drought tolerance at reproductive stage
3．4 Conclusion
CHAPTER 4 Connotation of RYMV resistance on high grain yield traits in rice
4．1 Introduction
4．1．1 Natural resistance
4．2 Methodology
4．2．1 Materials
4．2．2 Methods
4．2．3 Molecular screening for the RYMV1 gene resistance to RYMV
4．2．4 QTL analysis
4．3 Results and discussion
4．3．1 Response of WTR1 ILs to RYMV S4 strain
4．3．2 Evaluation of gene resistance to RYMV contained in the identified 39 ILs
4．3．3 Association of RYMV resistance QTL with high grain Yield QTL under irrigation and drought conditions
4．3．4 Collocation between RYMV QTL and High grain yield QTL
4．4 Conclusion
CHAPTER 5 The genes and QTL for yield under Multiple Biotic and abiotic stress
5．1 Introduction
5．2 Methodology
5．2．1 Materials
5．2．2 Data analysis
5．3 Results and discussion
5．3．1 Lead SNP(genes／QTL)with significant association with yield component traits
5．3．2 Overlapping lead SNPs(Genes／QTL)for various yield component traits
5．4 Conclusion
Overall conclusion and recommendation
6．1 General conclusions
6．2 Recommendations
References
Acknowlegments
Biographical scketch of the author
