抽穗前后极端温度对籼稻产量和品质的影响及其机理
发布时间：2020-10-16 04:59
水稻(Oryza sativa L.)产量和品质受极端温度影响显著,且水稻关键生育时期遭遇极端温度严重制约了稻米品质。研究表明,极端温度通常发生于水稻生殖生长阶段,但目前极端温度影响水稻生长的敏感时期及其机制仍不清楚。为此,本研究选择两个主栽籼稻品种(万象优华占和荣优华占),借助人工气候室开展盆栽试验,在江西省南昌市设置极端高温(HT)、极端低温(LT)和最适温度(CK)三个处理,共四个处理时段——抽穗前1周、抽穗后第1、2、3周,并对水稻产量、物质积累、光合特性和稻米品质等性状进行了分析比较,结果如下:极端温度显著影响水稻生育期、株型、光合特性和产量。与CK处理相比,HT处理下水稻抽穗期提前,株高增加,LT处理抽穗期延长,株高降低;极端温度显著降低了水稻剑叶叶绿素含量和叶绿素荧光;平均光合速率、气孔导度和蒸腾速率分别下降了41.5%,34.3%和51.2%。本研究表明,抽穗前1周和抽穗后第1周极端温度均显著降低了水稻产量。与CK处理相比,HT处理下两水稻品种的产量下降幅度为12.1%~15.8%,而LT处理的产量下降幅度为4.9%~13.1%。极端温度条件下两品种平均干物质转运量、干物质转运效率及其贡献率分别降低了18.2%、19.4%和11.9%。稻米品质对极端温度响应最敏感的时期主要集中于抽穗后第2周。HT处理下水稻精米率和整精米率、籽粒长宽比显著降低,垩白率、垩白度和垩白粒率均显著增加。水稻抽穗后第2周进行极端高温处理显著降低了淀粉峰值粘度、最低粘度、最终粘度、回复值和峰值时间。糊化温度、直链淀粉和蛋白质含量对高温和低温的响应不一致。HT处理糊化温度和蛋白质含量均显著增加,而直链淀粉含量降低;LT处理下糊化温度和蛋白质含量则显著降低。本研究进一步比较了水稻抽穗后第2周籽粒中Waxy和OsAAp6基因表达量、颗粒结合淀粉合成酶-1(GBSS1)和谷氨酸丙酮酸转氨酶(GPT),以及脱落酸(ABA)和水杨酸(SA)含量。结果表明,HT显著降低籽粒中Waxy基因相对表达量(75.6%~82.6%),增加OsAAP6基因相对表达量(14.4%~187.2%);LT处理则显著增加Waxy基因相对表达量。极端高温和极端低温均显著降低了GBSS1活性,两品种响应一致。与CK相比,HT显著增加GPT活性和ABA含量,而SA含量则显著降低;极端低温处理下ABA和SA含量均显著增加,GPT活性则显著下降。综上,水稻抽穗前和抽穗后1周的极端温度显著降低水稻产量。稻米品质受极端温度的影响主要集中在抽穗后第2周。花后极端高温对稻米品质的影响要显著大于极端低温。极端高温显著降低了水稻外观品质、加工品质和蒸煮食味品质。
【学位单位】：中国农业科学院
【学位级别】：博士
【学位年份】：2019
【中图分类】：S511.21
【文章目录】：
摘要
abstract
CHAPTER 1 General Introduction
1.1 Background of the study
1.2 Problem statement
1.3 Research questions
1.4 Hypothesis
1.5 Research framework
1.6 Main objectives
1.7 Specific objectives
1.8 Justification
1.9 Project component
CHAPTER 2 Literature review
2.1 Overview of rice production and quality
2.2 Global warming and extreme temperatures
2.3 Sensitivity of rice growth periods to extreme temperatures
2.4 Impacts of extreme high temperature on rice yield and quality
2.5 Impacts of extreme low temperature on rice yield and quality
2.6 Impacts of extreme temperature on genetic and molecular traits of rice grain quality
CHAPTER 3 Materials and methods
3.1 Site description
3.2 The experimental design
3.3 The walk-in climate chamber description
3.4 Photosynthetic traits
3.5 Plant sampling
3.6 Yield parameters
3.7 Milling and appearance quality
3.8 Cooking quality
3.9 Amylose content,protein content and gel consistency
3.10 Fresh grain sampling for gene,enzyme and hormonal tests
3.11 Gene expression analysis by quantitative PCR(qPCR)
3.12 Enzyme and hormonal activities
3.13 Statistical analysis
CHAPTER 4 Responses of indica rice yield and yield components to extreme temperatures
4.1 Introduction
4.2 Results
4.2.1 Plant growth duration and phonological parameters
4.2.2 Yield
4.2.3 Yield components
4.2.4 Total Biomass
4.2.5 Dry matter translocation and assimilation
4.2.6 Harvest index
4.3 Discussion
4.4 Conclusion
CHAPTER 5 Responses of photosynthetic parameters to extreme temperatures
5.1 Introduction
5.2 Results
5.2.1 Chlorophyll content
5.2.2 Chlorophyll fluorescence
5.2.3 Photosynthetic rate
5.2.4 Stomatal conductance
5.2.5 Transpiration rate
5.3 Discussion
5.4 Conclusion
CHAPTER 6 Impacts of extreme temperatures on indica rice grain quality
6.1 Introduction
6.2 Results
6.2.1 Milling quality
6.2.2 Appearance quality
6.2.3 Cooking quality
6.2.4 Amylose content,protein content and gel consistency of rice grain
6.3 Discussion
6.4 Conclusion
CHAPTER 7 Impacts and their underlying mechanisms of extreme temperatures on mutable amylose and protein contents in indica rice grain
7.1 Introduction
7.2 Results
7.2.1 The relative expressions of OsAAP6 and Waxy genes
7.2.2 The activities of GPT and GBSS1 enzymes
7.2.3 The activities of ABA and SA hormones
7.3 Discussion
7.4 Conclusion
CHAPTER 8 Discussion and Conclusion
8.1 Discussion
8.2 Conclusion
8.3 Recommendations
8.3.1 Innovation points
8.3.2 Recommendations
REFERENCES
ACKNOWLEDGEMENT
AUTHOR‘S RESUME
【参考文献】
本文编号：2842797
【学位单位】：中国农业科学院
【学位级别】：博士
【学位年份】：2019
【中图分类】：S511.21
【文章目录】：
摘要
abstract
CHAPTER 1 General Introduction
1.1 Background of the study
1.2 Problem statement
1.3 Research questions
1.4 Hypothesis
1.5 Research framework
1.6 Main objectives
1.7 Specific objectives
1.8 Justification
1.9 Project component
CHAPTER 2 Literature review
2.1 Overview of rice production and quality
2.2 Global warming and extreme temperatures
2.3 Sensitivity of rice growth periods to extreme temperatures
2.4 Impacts of extreme high temperature on rice yield and quality
2.5 Impacts of extreme low temperature on rice yield and quality
2.6 Impacts of extreme temperature on genetic and molecular traits of rice grain quality
CHAPTER 3 Materials and methods
3.1 Site description
3.2 The experimental design
3.3 The walk-in climate chamber description
3.4 Photosynthetic traits
3.5 Plant sampling
3.6 Yield parameters
3.7 Milling and appearance quality
3.8 Cooking quality
3.9 Amylose content,protein content and gel consistency
3.10 Fresh grain sampling for gene,enzyme and hormonal tests
3.11 Gene expression analysis by quantitative PCR(qPCR)
3.12 Enzyme and hormonal activities
3.13 Statistical analysis
CHAPTER 4 Responses of indica rice yield and yield components to extreme temperatures
4.1 Introduction
4.2 Results
4.2.1 Plant growth duration and phonological parameters
4.2.2 Yield
4.2.3 Yield components
4.2.4 Total Biomass
4.2.5 Dry matter translocation and assimilation
4.2.6 Harvest index
4.3 Discussion
4.4 Conclusion
CHAPTER 5 Responses of photosynthetic parameters to extreme temperatures
5.1 Introduction
5.2 Results
5.2.1 Chlorophyll content
5.2.2 Chlorophyll fluorescence
5.2.3 Photosynthetic rate
5.2.4 Stomatal conductance
5.2.5 Transpiration rate
5.3 Discussion
5.4 Conclusion
CHAPTER 6 Impacts of extreme temperatures on indica rice grain quality
6.1 Introduction
6.2 Results
6.2.1 Milling quality
6.2.2 Appearance quality
6.2.3 Cooking quality
6.2.4 Amylose content,protein content and gel consistency of rice grain
6.3 Discussion
6.4 Conclusion
CHAPTER 7 Impacts and their underlying mechanisms of extreme temperatures on mutable amylose and protein contents in indica rice grain
7.1 Introduction
7.2 Results
7.2.1 The relative expressions of OsAAP6 and Waxy genes
7.2.2 The activities of GPT and GBSS1 enzymes
7.2.3 The activities of ABA and SA hormones
7.3 Discussion
7.4 Conclusion
CHAPTER 8 Discussion and Conclusion
8.1 Discussion
8.2 Conclusion
8.3 Recommendations
8.3.1 Innovation points
8.3.2 Recommendations
REFERENCES
ACKNOWLEDGEMENT
AUTHOR‘S RESUME
【参考文献】
相关期刊论文 前1条
1 ;Salicylic Acid and its Function in Plant Immunity[J];Journal of Integrative Plant Biology;2011年06期
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