水稻(Oryza sativa L.)產(chǎn)量和品質(zhì)受極端溫度影響顯著,且水稻關(guān)鍵生育時(shí)期遭遇極端溫度嚴(yán)重制約了稻米品質(zhì)。研究表明,極端溫度通常發(fā)生于水稻生殖生長(zhǎng)階段,但目前極端溫度影響水稻生長(zhǎng)的敏感時(shí)期及其機(jī)制仍不清楚。為此,本研究選擇兩個(gè)主栽秈稻品種(萬(wàn)象優(yōu)華占和榮優(yōu)華占),借助人工氣候室開(kāi)展盆栽試驗(yàn),在江西省南昌市設(shè)置極端高溫(HT)、極端低溫(LT)和最適溫度(CK)三個(gè)處理,共四個(gè)處理時(shí)段——抽穗前1周、抽穗后第1、2、3周,并對(duì)水稻產(chǎn)量、物質(zhì)積累、光合特性和稻米品質(zhì)等性狀進(jìn)行了分析比較,結(jié)果如下:極端溫度顯著影響水稻生育期、株型、光合特性和產(chǎn)量。與CK處理相比,HT處理下水稻抽穗期提前,株高增加,LT處理抽穗期延長(zhǎng),株高降低;極端溫度顯著降低了水稻劍葉葉綠素含量和葉綠素?zé)晒?平均光合速率、氣孔導(dǎo)度和蒸騰速率分別下降了41.5%,34.3%和51.2%。本研究表明,抽穗前1周和抽穗后第1周極端溫度均顯著降低了水稻產(chǎn)量。與CK處理相比,HT處理下兩水稻品種的產(chǎn)量下降幅度為12.1%~15.8%,而LT處理的產(chǎn)量下降幅度為4.9%~13.1%。極端溫度條件下兩品種平均干物質(zhì)轉(zhuǎn)運(yùn)量、干物質(zhì)轉(zhuǎn)運(yùn)效率及其貢獻(xiàn)率分別降低了18.2%、19.4%和11.9%。稻米品質(zhì)對(duì)極端溫度響應(yīng)最敏感的時(shí)期主要集中于抽穗后第2周。HT處理下水稻精米率和整精米率、籽粒長(zhǎng)寬比顯著降低,堊白率、堊白度和堊白粒率均顯著增加。水稻抽穗后第2周進(jìn)行極端高溫處理顯著降低了淀粉峰值粘度、最低粘度、最終粘度、回復(fù)值和峰值時(shí)間。糊化溫度、直鏈淀粉和蛋白質(zhì)含量對(duì)高溫和低溫的響應(yīng)不一致。HT處理糊化溫度和蛋白質(zhì)含量均顯著增加,而直鏈淀粉含量降低;LT處理下糊化溫度和蛋白質(zhì)含量則顯著降低。本研究進(jìn)一步比較了水稻抽穗后第2周籽粒中Waxy和OsAAp6基因表達(dá)量、顆粒結(jié)合淀粉合成酶-1(GBSS1)和谷氨酸丙酮酸轉(zhuǎn)氨酶(GPT),以及脫落酸(ABA)和水楊酸(SA)含量。結(jié)果表明,HT顯著降低籽粒中Waxy基因相對(duì)表達(dá)量(75.6%~82.6%),增加OsAAP6基因相對(duì)表達(dá)量(14.4%~187.2%);LT處理則顯著增加Waxy基因相對(duì)表達(dá)量。極端高溫和極端低溫均顯著降低了GBSS1活性,兩品種響應(yīng)一致。與CK相比,HT顯著增加GPT活性和ABA含量,而SA含量則顯著降低;極端低溫處理下ABA和SA含量均顯著增加,GPT活性則顯著下降。綜上,水稻抽穗前和抽穗后1周的極端溫度顯著降低水稻產(chǎn)量。稻米品質(zhì)受極端溫度的影響主要集中在抽穗后第2周�；ê髽O端高溫對(duì)稻米品質(zhì)的影響要顯著大于極端低溫。極端高溫顯著降低了水稻外觀品質(zhì)、加工品質(zhì)和蒸煮食味品質(zhì)。
【學(xué)位單位】：中國(guó)農(nóng)業(yè)科學(xué)院
【學(xué)位級(jí)別】：博士
【學(xué)位年份】：2019
【中圖分類(lèi)】：S511.21
【文章目錄】：
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

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 ;Salicylic Acid and its Function in Plant Immunity[J];Journal of Integrative Plant Biology;2011年06期

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