乙烯对棉花适应淹水胁迫的作用及其机制

【目的】淹水胁迫影响棉花生长发育,持续淹水可导致棉花减产甚至绝产,增强棉花适应淹水胁迫的能力对棉花抗涝夺丰收至关重要。乙烯(Ethylene)是备受关注的重要信号分子,在植物抗逆过程中发挥着重要作用,但在缓解棉花淹涝伤害中作用和机制尚不清楚。本文以棉花(Gossypium hirsutum L.)品种K638为材料,在山东棉花研究中心试验站(山东临清)的田间电动遮雨棚内,对盛花期棉花淹水处理10 d,通过叶面喷施乙烯信号通路抑制剂1-甲基环丙烯(1-methylcyclopropene, 1-MCP)或乙烯合成前体1-氨基环丙烷-1-羧酸(1-Aminocyclopropane-1-carboxylic acid, ACC)抑制或促进棉株体内乙烯合成,探究了乙烯含量对棉花适应淹水胁迫的作用及其生理机制。结果表明,与未喷施的淹水处理相比,喷施1-MCP乙烯含量降低了5.3%,丙二醛(Malondialdehyde, MDA)、厌氧代谢酶乙醇脱氢酶(Alcohol dehydrogenase, ADH)、丙酮酸脱羧酶(Pyruvate decarboxylase, PDC)和乳酸脱氢酶(Lactate dehydrogenase, LDH)分别降低了39.2%、37.8%、20.5%和8.2%,主茎功能叶光合速率和单株干物质质量分别提高了13.5%和3.3%,籽棉产量提高了4.6%;而ACC的效果相反,喷施ACC促进受淹棉株体内乙烯积累,乙烯含量升高了8.0%,MDA、ADH、PDC和LDH分别增加了19.5%、17.5%、11.2%和8.0%,光合速率和单株干物质质量分别降低了6.0%和7.7%,籽棉产量减少了8.0%。由此可见,降低棉株体内乙烯含量,可显著降低活性氧对细胞膜的损伤,抑制厌氧代谢有毒产物的积累,减轻淹水胁迫下棉花所受的低氧损伤,缓解受淹棉株光合生产和生长发育的受抑制程度,一定程度上缓解了淹水胁迫造成的伤害,是提高棉花适应淹水胁迫的重要途径。     

植物响应淹水胁迫的研究进展

淹水胁迫是影响植物分布与生长发育的重要因素,植物耐涝性研究是提高作物耐涝性以应对日益严峻的极端气候及规模化生产管理的关键。为了合理开展植物耐涝性研究,深入挖掘不同植物响应淹水胁迫的调控机理,本文归纳了淹水胁迫对植物生长发育的影响,总结了植物响应淹水胁迫的调节机制,并详细分析了淹水胁迫对植物表型性状、生物量、光合作用、活性氧离子积累、糖含量和生物膜的影响,以及乙烯信号分子、活性氧清除机制、渗透调节、形态调节、分子和代谢调控在植物响应淹水胁迫中的调节机制。最后,通过总结,提出了合理开发外源调节物质提高作物耐涝性值得进一步的深入研究。     

棉花对重金属胁迫的应答反应与抗性机理研究进展

棉花是对重金属以及其它类型非生物逆境耐性较强的作物。虽然重金属胁迫对棉花的生长发育造成不利影响,但因棉花自身具有较完整的应对重金属胁迫的适应保护机制、且棉花主产品非食用的特点,可作为重金属污染土壤的修复作物。本文结合本实验室的研究结果,就国内外对镉、铬、铅、砷和汞5种主要重金属污染物源对棉花生长发育的毒害机理以及棉花应对和适应机制的研究进展作了评述。     

S3307对始花期和始粒期淹水绿豆光合作用及产量的影响

淹水胁迫是作物生长发育过程中遭受的主要非生物胁迫之一,探究提高绿豆耐淹性的机制对绿豆抗涝栽培具有重要意义。本文在2017—2018年以耐淹性不同的绿豆品种绿丰2号和绿丰5号为试验材料,采用盆栽方式探究了烯效唑(S3307)对淹水胁迫下绿豆叶片生理、光合作用及产量的影响。结果表明,在不同生育时期淹水胁迫下,绿豆叶片的叶绿素含量(SPAD)及光合特性参数均显著下降,丙二醛(MDA)含量显著增加,始花期(R1期)淹水胁迫下绿豆的减产率为24.70%～33.63%,始粒期(R5期)减产率为18.07%～28.87%。2个绿豆品种均表现为R1期受淹水胁迫危害程度大于R5期,绿丰2号耐淹性强于绿丰5号。喷施S3307后显著提高淹水胁迫下绿豆叶片的SPAD、净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs),并显著降低了MDA含量。绿豆在R1期淹水胁迫下的缓解率为28.91%～52.34%,R5期缓解率为13.77%～27.36%。表明叶面喷施S3307可有效提高淹水胁迫下绿豆叶片的生理功能及光合能力,进而降低减产幅度,但不同淹水时期和绿豆品种对S3307的调控响应存在差异。     

洪涝灾害对水稻生产的影响评估及抗灾对策研究

采用系统调查的方法,调查分析了超级稻和常规稻在分蘖期不同淹水时间对生长发育及产量的影响,提出了水稻受灾后技术抗灾对策和关键技术措施。不同淹水条件下,超级稻和常规稻均随淹水时间延长减产幅度加大,产量降低的原因主要是有效穗数、穗总粒数和千粒重下降,且全生育期延长。超级稻对淹水胁迫的抗性和适应能力优于常规稻,受害轻,恢复生长快,减产幅度低。早稻翻秋种植是灾后重要的补救措施,其关键技术是适时早播,适当增加播种量。     

洪涝对棉花产量及其品质的影响

采用正交组合设计,研究了洪涝中各因素对棉花产量、产量构成因素及其品质的影响。结果表明:(1)淹水天数、淹水深度、淹水生育期对棉花产量有显著影响,各因素对棉花产量的影响主要是减少了总铃数,而且在淹水条件下棉花品质降低。(2)棉花蕾期对淹水最敏感,减产最严重。并且其棉花品质(纤维整齐度、平均纤维长)显著降低。     

盐分胁迫对植物的影响及植物耐盐机理研究进展

盐分是影响植物生长的一个重要环境因素。总结了盐分胁迫对植物生长发育影响的研究进展,从氧自由基产生、膜脂过氧化、离子伤害、渗透伤害和有毒物质积累等方面系统分析了盐胁迫对植物的伤害机理,并综述了植物对盐分胁迫的适应机制,总结了主要的抗盐生理指标。     

杂草与棉花的竞争作用

概述了国内外杂草与棉花竞争作用的研究进展和现状,归纳总结了杂草种类、杂草密度及杂草与作物的不同共生期对棉花产量、生长发育、品质、农事操作等影响。但现有研究主要集中在棉花最终产量和最终生长指标的分析上,而对棉花生长发育动态影响,尤其是内在机制的研究还比较少。因此,进一步细化研究棉花生长发育动态的形态指标和生理生化指标及与环境之间的关系,才能全面分析杂草与棉花的竞争作用,探明棉花响应杂草竞争胁迫的内在机制。     

淹水胁迫对水稻玉香油占秧苗生长和生理特性的影响

为探究淹水胁迫对水稻秧苗的影响,以水稻品种玉香油占为材料,通过盆栽试验研究了淹水胁迫对其秧苗生长发育和生理特性的影响。淹水处理分为3个水平:无淹水(CK)、淹水1.0~1.9cm(W1)、淹水2.0~2.9cm(W2)。结果表明,随着淹水程度的加深,秧苗地上部的光合色素含量、生物量、可溶性糖含量均明显下降,白根数和总根数明显增加。而SOD活性、POD活性、游离脯氨酸含量呈现先降后升的趋势,CAT活性、可溶性蛋白含量、MDA含量呈现先升后降的趋势。     

植物高温胁迫响应分子机制研究

作为固着生物,植物需要面对持续变化的环境,不断地受到温度和其他非生物因素的影响。未来植物所面临的平均环境温度将会随着全球气候变暖逐渐上升,因此高温愈发成为影响植物生长发育、地理分布及产量的非生物胁迫因子。了解植物对高温胁迫的适应机制,有助于开发耐热品种,改善温暖气候地区植物的生长状况以及提高作物的生产力。植物体中,在分子水平,转录组学及蛋白质组学联合揭示了mRNA以及蛋白水平的植物应答高温胁迫的基因表达模式变化;另外高温胁迫广泛涉及植物体内多种信号转导机制。因此,本综述主要从植物响应高温胁迫分子水平上的转录组、蛋白质组学方面,以及信号转导等方面全面总结了植物响应高温胁迫的研究进展,并对未来的研究前景进行了展望,为了解近几年高温胁迫研究动态和高温胁迫常见研究方式,解析植物高温胁迫耐受机理以及耐高温品种的培育提供参考。     

棉花涝害胁迫研究综述

涝害是棉花生产中面临的重要自然灾害之一,严重制约了棉花种植面积和产量。为了研究涝渍灾害对棉花生长发育状况的影响,本研究从棉花的形态生长、生理特性及植物激素变化等方面概述了涝害胁迫的研究现状及进展,分析了涝害对棉花生理机制造成的影响,以及涝害胁迫下棉花通气组织的形成及酶代谢适应性变化,并就棉花耐涝性鉴定方法、评价指标及其品种选育等提出了需要进一步研究和探讨的建议。     

Effects of Ethylene on Cotton Adaption to Waterlogging Stress and the Underlying Mechanism

[Objective] Waterlogging adversely affects cotton growth and development, and continuous waterlogging may further result in considerable yield loss or crop failure. Enhancing the ability of cotton to adapt to waterlogging stress to preserve yield and quality is therefore critical. Ethylene is an important signal molecule, which plays a vital role in the process of plant stress resistance. However, the mechanism of ethylene in mitigating cotton waterlogging damage is still unclear. [Method] In this study, we setup an experiment with a cotton (Gossypium hirsutum L.) variety K638 in an electric rain shelter at the experimental station of the Shandong Cotton Research Center at Linqing, Shandong. We treated the cotton plants by waterlogging for 10 d during the flowering stage and used a non-waterlogged treatment as the control. During the waterlogging stress treatment, cotton plants were treated with an ethylene signal transduction inhibitor (1-MCP) or ethylene synthesis precursor (ACC) to detect the effects of ethylene content on cotton waterlogging injury and its physiological mechanism. [Result] The results revealed that a foliar spray of 1-MCP significantly inhibited ethylene synthesis in the stressed cotton plants, the content of ethylene and malondialdehyde (MDA) decreased by 5.3% and 39.2%, and the activities of alcohol dehydrogenase (ADH), pyruvate decarboxylase (PDC), and lactate dehydrogenase (LDH) decreased by 37.8%, 20.5%, and 8.2%, respectively. The photosynthetic rate, dry weight of the whole plant, and seed cotton yield increased by 13.5%, 3.3%, and 4.6%, respectively. The effect of ACC on the plants was the opposite because spraying ACC promoted ethylene accumulation in the waterlogged cotton. The ethylene and MDA content increased by 8.0% and 19.5%, respectively. The activities of ADH, PDC, and LDH increased by 17.5%, 11.2%, and 8.0%, respectively, while the photosynthetic rate, dry weight of the whole plant, and seed cotton yield decreased by 6.0%, 7.7%, and 8.0%, respectively. [Conclusion] In summary, reducing ethylene content in waterlogged cotton plants can significantly alleviate hypoxia damage caused by waterlogging stress and subsequently promote cotton growth and development by restoring physiological metabolism.     

氮素对花铃期短期渍水棉花根系生长的影响

于2005—2006年在江苏南京农业大学卫岗试验站进行盆栽试验,设置正常灌水(土壤含水量为田间持水量的75%左右)和棉花花铃期土壤短期渍水处理(将正常灌水的棉花增加灌水至盆内有可见明水,持续8 d,然后用导管排除表面水层,使盆内土壤含水量逐渐恢复到田间持水量的75%左右),每个水分处理设置3个氮素水平(0、3.73、7.46 g N pot^-1,分别相当于大田0、240、480 kg N hm^-2),研究氮素对花铃期短期渍水棉花根系生长的影响。结果表明,在渍水处理结束时,与正常灌水处理相比,根干重和根冠比(R∶S)均降低;根系可溶性蛋白含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性降低,过氧化物酶(POD)活性升高,丙二醛(MDA)含量升高;棉花根系活力和单株光合速率(CAP)显著降低。增加施氮可降低渍水棉花根系SOD活性,提高POD和CAT活性,以3.73 g N pot^-1(240 kg N hm^-2)施氮水平下的棉花根干物重最大,根系MDA含量最低,根系活力最强,单株光合速率(CAP)最高,相应籽棉产量最高。渍水停止15 d后,渍水棉花根系抗氧化酶活性和MDA含量与正常灌水处理的差异较小;施氮仍可提高棉花根系POD与CAT活性,降低MDA含量,增强根系活力,提高CAP。     

氮素对花铃期短期渍水棉花根系生长的影响

于2005—2006年在江苏南京农业大学卫岗试验站进行盆栽试验,设置正常灌水(土壤含水量为田间持水量的75%左右)和棉花花铃期土壤短期渍水处理(将正常灌水的棉花增加灌水至盆内有可见明水,持续8 d,然后用导管排除表面水层,使盆内土壤含水量逐渐恢复到田间持水量的75%左右),每个水分处理设置3个氮素水平(0、3.73、7.46 g N pot^-1,分别相当于大田0、240、480 kg N hm^-2),研究氮素对花铃期短期渍水棉花根系生长的影响。结果表明,在渍水处理结束时,与正常灌水处理相比,根干重和根冠比(R∶S)均降低;根系可溶性蛋白含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性降低,过氧化物酶(POD)活性升高,丙二醛(MDA)含量升高;棉花根系活力和单株光合速率(CAP)显著降低。增加施氮可降低渍水棉花根系SOD活性,提高POD和CAT活性,以3.73 g N pot^-1(240 kg N hm^-2)施氮水平下的棉花根干物重最大,根系MDA含量最低,根系活力最强,单株光合速率(CAP)最高,相应籽棉产量最高。渍水停止15 d后,渍水棉花根系抗氧化酶活性和MDA含量与正常灌水处理的差异较小;施氮仍可提高棉花根系POD与CAT活性,降低MDA含量,增强根系活力,提高CAP。     

江淮地区涝渍灾害分析

摘要：涝渍灾害是江淮地区农作物生育期间的主要农业气象灾害之一。江淮地区涝渍灾害发生频繁,危害作物多,受灾范围广,对生产建设和人民生活造成巨大困难和损失,严重制约着该地区农业和经济的可持续发展。本文对江淮地区涝渍灾害的特点和致灾原因进行了分析,并提出了相应的防涝防渍措施。     

Waterlogging events during stem elongation or flowering affect yield of oilseed rape (Brassica napus L.) but not seed quality

Oilseed rape suffers from serious waterlogging in many regions of the world limiting the cultivation area for rapeseed. Due to the man‐induced climate change, the risk of severe waterlogging events and associated therewith the damage of rapeseed plants will increase, even in Europe and North America. To investigate the effects of waterlogging on growth, yield and seed quality, rapeseed was cultivated throughout its vegetation period and waterlogged for 14 days at two different growth stages: at stem elongation (BBCH 31) or at floral bud appearance (BBCH 55). The experiments revealed that waterlogging at BBCH 31 affected plant growth and nutrient accumulation and finally resulted in lower yields. Waterlogging at BBCH 55 seriously impaired main racemes, but due to an increased production of secondary racemes, yield losses were lower than after waterlogging at BBCH 31. Oil quality was not affected by any waterlogging treatment under the chosen experimental conditions.     

结实期渍水对糯玉米籽粒产量和品质的影响

结实期是玉米籽粒产量和品质形成的关键时期,在中国南方夏季经常遭遇涝渍危害。以6个糯玉米品种为材料,研究分析了结实期（花后1~7天）渍水对糯玉米籽粒产量和品质的影响。结果表明：结实期渍水导致糯玉米粒数减少、粒重降低,进而导致产量损失。渍水使籽粒可溶性糖和淀粉含量降低,蛋白质含量升高。籽粒峰值黏度和崩解值除‘农科玉301’受渍水影响较小外,其他品种均显著降低,但不同品种谷值黏度、终值黏度和回复值对渍水响应不一。结实期渍水对糯玉米籽粒糊化和胶凝温度影响较小。热焓值‘皖糯5号’和‘美玉16’在渍水处理下显著降低,其他品种保持不变。相反,渍水使各品种（‘美玉16’除外）的回生热焓值和回生值增加。综上,结实期渍水导致籽粒产量降低、品质变劣（黏度降低、回生增加）。     

盐渍和涝渍对棉苗生长和叶片某些生理性状的复合效应

 以陆地棉鲁棉研17和鲁棉研28为材料,以无盐正常供水为对照,研究了在盐渍、涝渍和盐涝复合胁迫14 d后棉苗干物质积累、叶片光合速率、叶绿素荧光参数和叶绿素含量等的变化。结果表明,盐渍、涝渍和盐涝复合胁迫都显著影响两个品种的光合速率和干物质积累。盐渍对棉苗的影响程度小于涝渍,而涝渍又小于盐涝复合胁迫,盐涝双重胁迫对棉苗生长和干物质积累的抑制表现出累加效应。盐渍胁迫下叶绿素含量的下降是光合作用受抑制的重要原因,而涝渍和盐涝胁迫下光合速率下降可能是叶绿体结构和PSⅡ稳定性的下降引起的。     

Low Incident Light Combined with Partial Waterlogging Impairs Photosynthesis and Imposes a Yield Penalty in Cotton

Through field studies, cotton responses to dual stresses – waterlogging and low light (shade) were investigated. The hypothesis was that shade would amplify yield losses in waterlogged (WL) cotton. Either early or late in the reproductive phase, the crop was WL (96 h and 120 h, in 2012–2013 and 2013–2014, respectively) and/or shaded (6 days or 9 days in 2012–2013 and 2013–2014, respectively). Waterlogging at early reproductive phase significantly reduced lint yield (17 % averaged across both years) of cotton, although shade‐induced yield losses (18 %) were only significant in 2013–2014. Shade significantly exacerbated yield losses only when the impact of waterlogging damage was modest (2013–2014). More intense waterlogging impaired lint yield independently of the light levels. Yield reductions in these experiments were the consequence of both accelerated fruit abscission and fewer fruiting nodes produced. Plants had lower leaf nitrogen levels and photosynthetic rates after waterlogging and/or shade treatments and produced fewer fruiting nodes. Although long‐term shade increased specific leaf area (30 %) and leaf N (20 %) immediately following 5 days of waterlogging, it did not restore shoot growth, node formation or lint yield because of suppressed photosynthetic performance (area basis) and carbohydrate supply.