| ACKNOWLEDGEMENTS | 第11-13页 |
| ABSTRACT | 第13-15页 |
| 摘要 | 第16-18页 |
| ABBREVIATIONS | 第18-30页 |
| CHAPTER 1 General Introduction and Review of Literature | 第30-52页 |
| 1.1 Background information | 第30-33页 |
| 1.2 Research objectives | 第33-35页 |
| 1.2.1 General objective | 第33页 |
| 1.2.2 Specific objectives | 第33-35页 |
| 1.3 Review of Literature | 第35-52页 |
| 1.3.1 Distribution and interspecific hybridization in genus Cucurbita | 第35-39页 |
| 1.3.1.1 History and climatic distribution of cucurbits | 第35-36页 |
| 1.3.1.2 Breeding history of interspecific hybridization in Cucurbita | 第36-37页 |
| 1.3.1.3 Development and some morphological characteristics of an interspecific inbred line 'Maxchata' | 第37-39页 |
| 1.3.2 Photosynthesis and heat stress | 第39-42页 |
| 1.3.3 Heat stress induced ultrastructural modification | 第42-43页 |
| 1.3.4 Heat stress and Reactive oxygen species | 第43-47页 |
| 1.3.4.1 ROS production | 第43-44页 |
| 1.3.4.2 Lipid peroxidation (LPO) | 第44-45页 |
| 1.3.4.3 ROS balance | 第45-47页 |
| 1.3.5 Cellular Respiration and redox homeostasis | 第47-49页 |
| 1.3.6 Alternative oxidase (AOX) genes family | 第49-52页 |
| CHAPTER 2 Determining Heat Tolerance of Interspecific (Cucurbita maxima x Cucurbita moschata) Inbred Lineof squash 'Maxchata' and its parents through Photosynthetic Response | 第52-60页 |
| Summary | 第52页 |
| 2.1 Introduction | 第52-54页 |
| 2.2 Materials and Methods | 第54-55页 |
| 2.2.1 Plant material and experimental conditions | 第54页 |
| 2.2.2 Chlorophyll extraction and quantification | 第54页 |
| 2.2.3 CO_2 assimilation | 第54页 |
| 2.2.4 Chlorophyll florescence | 第54-55页 |
| 2.2.5 Statistical analysis | 第55页 |
| 2.3 Results and Discussion | 第55-60页 |
| 2.3.1 Effect of heat stress on P_N, g_s, E and Ci | 第55-56页 |
| 2.3.2 Change in maximum photochemical efficiency of PSII | 第56-57页 |
| 2.3.3 Changes in chlorophyll and carotenoid contents | 第57-60页 |
| CHAPTER 3 Cloning and Characterization of Some Key Antioxidant Genes in Squashes | 第60-76页 |
| Summary | 第60页 |
| 3.1 Introduction | 第60-63页 |
| 3.1.1 Some key antioxidant genes | 第61-62页 |
| 3.1.2 Rapid amplification of complementary DNA ends (RACE) | 第62-63页 |
| 3.2 Materials and methods | 第63-66页 |
| 3.2.1 Total RNA isolation and cDNA synthesis | 第63页 |
| 3.2.2 Primer designing | 第63-64页 |
| 3.2.3 Cloning of cDNA encoding some antioxidant genes | 第64-65页 |
| 3.2.4 Sequence analysis and multiple alignments | 第65-66页 |
| 3.3 Results and discussion | 第66-76页 |
| 3.3.1 Superoxide dismutase copper zinc (Cu/ZnSOD) | 第66-67页 |
| 3.3.2 Superoxide dismutase iron (FeSOD) | 第67页 |
| 3.3.3 Superoxide dismutase manganese (MnSOD) | 第67-68页 |
| 3.3.4 Catalase 1 (CAT1) | 第68-70页 |
| 3.3.5 Catalase 2 (CAT2) | 第70页 |
| 3.3.6 Catalase 3 (CAT3) | 第70-72页 |
| 3.3.7 Ascorbate peroxidase 1 (APX1) | 第72-73页 |
| 3.3.8 Ascorbate peroxidase 2 (APX2) | 第73-74页 |
| 3.3.9 Actin | 第74-76页 |
| CHAPTER 4 Dissecting Heat Stress-Induced Alterations in Leaf Ultrastructure and Some Antioxidant NetworkComponents in 'Maxchata' and Its Parents Possessing Variable Heat Tolerance | 第76-97页 |
| Summary | 第76页 |
| 4.1 Introduction | 第76-78页 |
| 4.2 Materials and Methods | 第78-83页 |
| 4.2.1 Plant materials and experimental conditions | 第78-79页 |
| 4.2.2 Determination of lipid peroxidation and levels of hydrogen peroxide and superoxide radicals | 第79页 |
| 4.2.3 Extraction and determination of proline | 第79-80页 |
| 4.2.4 Determination of electrolyte leakage percentage (ELP) | 第80页 |
| 4.2.5 Measurement of the enzyme activities | 第80-81页 |
| 4.2.6 Microscopic study | 第81页 |
| 4.2.7 Total RNA isolation and cDNA synthesis | 第81页 |
| 4.2.8 Quantitative real time-polymerase chain reaction (qRT-PCR) analysis | 第81-83页 |
| 4.2.9 Reverse transcriptase-polymerase chain reaction (RT-PCR) | 第83页 |
| 4.2.10 Statistical analysis | 第83页 |
| 4.3 Results and Discussion | 第83-97页 |
| 4.3.1 Analysis of membrane damage using biomarkers | 第83-86页 |
| 4.3.2 Heat induced ultrastructural changes | 第86-90页 |
| 4.3.3 Activities of enzymatic antioxidants and their transcript abundance levels | 第90-97页 |
| CHAPTER 5 Antioxidant Enzymatic Activities and Gene Expression Associated With Heat Tolerance in the Stemsand Roots of 'Maxchata' and Its Parents | 第97-115页 |
| Summary | 第97页 |
| 5.1 Introduction | 第97-99页 |
| 5.2 Materials and Methods | 第99-103页 |
| 5.2.1 Plant Materials and Experimental Conditions | 第99-100页 |
| 5.2.2 Quantification of ROS (H_2O_2 and O_2~-) Production | 第100页 |
| 5.2.3 Determination of lipid peroxidation | 第100-101页 |
| 5.2.4 Measurement of the Enzyme Activities | 第101页 |
| 5.2.5 Total RNA Isolation and cDNA Synthesis | 第101页 |
| 5.2.6 Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) Analysis | 第101-102页 |
| 5.2.7 Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) | 第102-103页 |
| 5.2.8 Statistical Analysis | 第103页 |
| 5.3 Results and Discussion | 第103-115页 |
| 5.3.1 Effect of Heat Stress on Reactive Oxygen Species Production | 第103-106页 |
| 5.3.2 Effect of heat stress on lipid peroxidation | 第106页 |
| 5.3.3 Activities of enzymatic antioxidants and transcript abundance levels of antioxidant genes | 第106-115页 |
| CHAPTER 6 Cloning and Characterization of Alternative Oxidase (AOX) Genes in Squashes and Comparing theirExpressions in Young and Mature Plants | 第115-144页 |
| Summary | 第115页 |
| 6.1 Introduction | 第115-118页 |
| 6.1.1 A general view of Alternative oxidase (AOX) | 第115-116页 |
| 6.1.2 Variation of AOX gene organization | 第116-118页 |
| 6.2 Materials and methods | 第118-123页 |
| 6.2.1 Total RNA isolation and cDNA synthesis | 第118页 |
| 6.2.2 Primer designing | 第118-119页 |
| 6.2.3 Cloning of cDNA encoding some antioxidant genes | 第119-120页 |
| 6.2.4 Sequence analysis and multiple alignments | 第120-122页 |
| 6.2.5 Quantitative real time-polymerase chain reaction (qRT-PCR) analysis | 第122-123页 |
| 6.3 Results and discussion | 第123-144页 |
| 6.3.1 Alternative oxidase genes family | 第123-137页 |
| 6.3.1.1 Alternative oxidase2a (CmAOX2a) | 第128-130页 |
| 6.3.1.2 Alternative oxidase 2b (CmAOX2b) | 第130-132页 |
| 6.3.1.3 Alternative oxidase 2c (CmAOX2c) | 第132-134页 |
| 6.3.1.4 Alternative oxidase 2d (CmAOX2d) | 第134-136页 |
| 6.3.1.5 Alternative oxidase 2e (CmAOX2e) | 第136-137页 |
| 6.3.2 Cytochrome c oxidase 2 (CmCOX2) | 第137-139页 |
| 6.3.3 Chaperonin 60 (CmCPN60) | 第139-140页 |
| 6.3.4 Expression of alternative oxidase genes of squashes in young and mature plants | 第140-144页 |
| CHAPTER 7 Determining the Role of Alternative Respiratory Pathway in Heat Tolerance of Cucurbita maxima,Cucurbita moschata and their Interspecific Inbred Line 'Maxchata' | 第144-159页 |
| SUMMARY | 第144页 |
| 7.1 Introduction | 第144-146页 |
| 7.1.1 Cellular Respiration and redox homeostasis | 第144-145页 |
| 7.1.2 Function of AOX as ROS avoidant | 第145-146页 |
| 7.2 Materials and Methods | 第146-150页 |
| 7.2.1 Plant material and experimental conditions | 第146-148页 |
| 7.2.2 Measurement of respiration | 第148页 |
| 7.2.3 Staining for O~(2-) and H_2O_2 | 第148页 |
| 7.2.4 Determination of hydrogen peroxide and superoxide radicals | 第148-149页 |
| 7.2.5 Total RNA isolation and cDNA synthesis | 第149页 |
| 7.2.6 Quantitative real time-polymerase chain reaction (qRT-PCR) analysis | 第149页 |
| 7.2.7 Statistical analysis | 第149-150页 |
| 7.3 Results and Discussion | 第150-159页 |
| 7.3.1 Effect of heat stress on rate of respiration | 第150-151页 |
| 7.3.2 Effect of heat stress on ROS production in SHAM and water treated leaves | 第151-154页 |
| 7.3.3 The effect of heat stress on genes expression of some antioxidant genes in SHAM and water treated squashes | 第154-155页 |
| 7.3.4 The effect of heat stress on genes expression of alternative oxidase genes in squashes leaves | 第155-159页 |
| CHAPTER 8 Overall Conclusions and Future Prospects | 第159-162页 |
| 8.1 Overall conclusions | 第159-160页 |
| 8.2 Future prospects | 第160-162页 |
| REFERENCES | 第162-181页 |
| CURRICULAM VITEA | 第181-182页 |
