Thesis Advisor陈亚宁
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Discipline理学博士
Keyword抗氧化系统 作物增产 干旱 外源 H2O2 渗透调节 藜麦 Antioxidant system Crop enhancement Drought Exogenous H2O2 Osmotic adjustment Quinoa
Abstract干旱是严重限制作物生产的主要非生物胁迫因素。最近的气候变化情景研究结果显示,全球变暖会导致缺水地区的干旱和盐胁迫风险增加,从而加剧了对农作物生产的威胁。与此同时,到 2050 年要养活 93 亿人,对农业科学家来说是一个巨大的挑战,缺水条件下如何提高农作物产量成为农业科技工作者攻克的热点问题。其中,为适应未来气候变化,选择合适的农作物品种是现有的粮食生产系统中的一种可行性选择。藜麦是一种极具营养价值的粮食作物,且具有耐旱等忍受恶劣环境条件的潜力。本研究选择藜麦为主要对象,通过施用外源 H2O2,采用四种藜麦基因型(Colorado-407D, IESP, 2-Want 和 Pichaman)作为实验对象,进行了一系列实验,评估了藜麦对干旱胁迫的响应和耐受性。在初步实验和文献综述的基础上,该实验选择干旱处理(范围; 30-50%PWHC)和用于种子引发(80 mM) ,土壤浸润(20mM)和叶面处理(15mM)的不同浓度 H2O2用于详细研究。在第一个实验中,评估了干旱胁迫下不同的过氧化氢施用方法,发现叶面喷雾(15mM)有效减轻干旱对藜麦的有害影响;在第二个实验中,我们研究了对干旱和 H2O2应用的基因型反应。根据我们的研究结果,将基因型分为高耐受性(2-Want- IESP) 、中等耐受性 (Colorado-407D) 和干旱敏感性 (Pichaman) 。在第三个实验中,使用了 H2O2种子引发和叶面施用方法的组合,研究结果表明,施用外源 H2O2(种子引发+叶面喷施)增加了 Pichaman(敏感基因型)的耐旱性。藜麦是一种盐生植物,因此,我们进一步研究调查了 H2O2在干旱和盐胁迫下的作用。研究结果表明,藜麦在盐和干旱同时胁迫下,施用外源 H2O2可以有效提升藜麦作物的抗逆性。由于藜麦的生长和产量在干旱胁迫下减少,并且这种减少归因于较低的气体交换、降低的光合活性和增加的 ROS 生产,这加速了氧化损伤。然而,外源 H2O2可以有效缓解干旱胁迫下的氧化损伤,并显着改善藜麦的表现。在干旱胁迫下, H2O2对藜麦生长的改善与气体交换属性增加有关,包括(气孔导度,蒸腾作用和光合用,通过有机物(脯氨酸, TSS, TSP, GB)和无机物(K+)的更高积累改善渗透调节。 (Mg+, Ca2+)渗透物 ABA 调节和通过显着的抗氧化活性(SOD, POD, CAT, APX, GPX, PAL, PPO 和 AsA)有效清除ROS 有助于减少氧化损伤。主成分分析表明,脯氨酸、 SOD、 TSP、叶绿素总量、 MSI、 RWC 等生理生化性状与籽粒产量呈较强的正相关关系,叶面施 H2O2对籽粒产量的贡献远大于种子引施和土壤淋施。总之,可以选择叶面施 H2O2 (15mM) 来改善藜麦的渗透调节和抗氧化系统,即使是在干旱和盐胁迫环境下,也可以提高藜麦对干旱胁迫的耐受性。此外,本研究还表明,筛选出的抗旱基因型也可广泛应用于其他干旱缺水地区。
Other AbstractDrought is a major abiotic stress which seriously limiting the global cropproduction, and recent climate change scenario has made this situation morehazardous by increasing the risk of salinity stress in water scarce regions. At the sametime, to feed 9.3 billion people by 2050 is a big challenge for agriculturist and force toenhance crop production under water scarcity. In this scenario, a viable option couldbe to add climate resilient grain crops in our existing food production system.Therefore, Chenopodium quinoa Willd., a highly nutritious grain crop havingpotential to endure harsh environmental conditions such as drought stress, wasselected for this study.A series of experiments were conducted to evaluate the quinoa responses todrought stress and tolerance enhancement through exogenous application of H2O2.The four quinoa genotypes (Colorado-407D, IESP, 2-Want and Pichaman) used asplant material. On the basis of preliminary experiments and literature review; droughttreatments (range; 30-50% PWHC) and H2O2 concentration for seed priming (80mM),soil drenching (20mM), and foliar treatment (15mM) were selected for detailedinvestigation. In first experiment, different hydrogen peroxide application methodswere evaluated under drought stress and foliar spray (15mM) was found effective toalleviate deleterious effects of drought in quinoa. In second experiment, genotypicresponse to drought and H2O2 application was investigated and on the basis of ourfindings genotypes were categorized as high tolerant (2-Want- IESP), moderatetolerant (Colorado-407D) and drought sensitive (Pichaman). In third experiment,combination of H2O2 seed priming and foliar application methods was elucidated andresults revealed that exogenous H2O2 application (seed priming + foliar spray)increased drought tolerance in Pichaman (sensitive genotype). Quinoa is a halophyticcrop, so investigation was further extended to evaluate the role of H2O2 undercombined drought and salinity stress. Our results revealed, that quinoa effectivelytolerated drought stress under saline conditions and exogenous application of H2O2further improved the stress tolerance mechanism in quinoa crop.Since, growth and yield of quinoa reduced under drought stress and thisreduction was attributed to lower gaseous exchange, decreased photosynthetic activityand increased ROS production which accelerated the oxidative damages. However,exogenous H2O2 efficiently alleviated the oxidative damages and significantlyimproved quinoa performance under drought stress. The improved growth due toH2O2 under drought stress was associated with increased gas exchange attributesincluding (stomatal conductance, transpiration, and photosynthetic activity), improvedosmotic adjustment through higher accumulation of organic (proline, TSS, TSP, GB)and inorganic (K+, Mg+, Ca2+) osmolytes, ABA regulation and efficient scavenging ofROS through pronounced antioxidant activity (SOD, POD, CAT, APX, GPX, PAL,PPO and AsA) helped to reduce oxidative damages. The PCA analysis indicated thatphysio-biochemical traits (proline, SOD, TSP, total chlorophyll, MSI and RWC) werestrongly and positively correlated with grain yield and their contribution was muchhigher under foliar application of H2O2 compared to seed priming and soil drenchingapplication methods.In short, foliar application of H2O2 (15mM) may be opted to improve osmoticadjustment and antioxidant system of quinoa in order to enhance its tolerance againstdrought stress, even under combined drought and saline conditions. In addition, thisstudy also suggests that the screened out drought-resilient genotypes could also bewidely adopted on the marginal lands of water scarce regions.
Subject Area生态学
Document Type学位论文
First Author Affilication中国科学院新疆生态与地理研究所
Recommended Citation
GB/T 7714
HASSAN 1QBAL. 藜麦在水分亏缺条件下对外源过氧化氢的氧化防御系统和生理生化响应[D]. 北京. 中国科学院大学,2019.
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