棉花耐盐机理与盐害控制研究进展

综述了棉花耐盐机理、耐盐性鉴定方法和盐害控制技术的研究进展。棉花耐盐机理与一般植物存在着较大的差异,对盐分胁迫下的植株体内离子分布、细胞膜结构和稳定性以及渗透压调节作用等方面进行了探讨,总结了运用传统育种和现代生物技术改良和提高棉花耐盐性方面取得的进展。此外,提出了从棉花品种、栽培技术、种子引发技术和土壤改良等方面盐碱地植棉的综合技术体系。     

外源调节物质对盐胁迫下植物生长调控研究进展

为了探究外源物质对植物耐盐性的调控机理及进一步利用外源调节物质提高作物耐盐性,归纳了五大类传统植物激素（生长素、赤霉素、乙烯、脱落酸、细胞分裂素）以及褪黑素、水杨酸、多胺、油菜素类固醇、茉莉酸类等外源生长调节物质对盐胁迫下植物生长的调控情况。同时总结了硅、钙等离子类外源调节物对盐胁迫下植物生长的调节作用,多种外源调节物质可通过增强光合作用、提高渗透势、增加抗氧化酶活性及减少离子毒害等方式来减轻盐害。本文为进一步利用单一或复合外源调节物质来缓解作物盐害盐提供理论依据。     

棉花耐盐性研究进展

棉花是最耐盐的农作物之一，其耐盐性因品种、生育阶段、器官以及土壤盐分种类等不同而差异较大。盐胁迫对棉花的伤害主要是盐离子对幼嫩器官或发育转换时期的细胞膜结构和功能的伤害，抑制棉苗生长，影响生育进程，减少总果节数，降低产量品质。棉花的耐盐机理在于地上部对盐分的区域化分布，减少光合细胞质中盐离子浓度，增强盐胁迫条件下棉花对Ｋ＋、Ｃａ２＋、ＮＯ－３、Ｈ２ＰＯ－４等离子的吸收、运输和转化。     

棉花盐害与耐盐性的生理和分子机理研究进展

盐胁迫通过离子毒害、营养失衡和渗透胁迫,引起棉株体生理生化代谢失调,进而影响棉花的生长发育和产量、品质。但棉株体可以通过膜脂过氧化清除系统活性的提高维持质膜的相对稳定,通过合成和积累脯氨酸、葡萄糖和氨基酸等小分子有机物质缓解渗透胁迫,通过调节盐离子在不同器官、组织或细胞内的区域(隔)化分布减轻离子毒害,而表现出较强的耐盐性。Na /H 反向转运蛋白和LEA蛋白(晚期胚胎发生富集蛋白)等的合成及其相关基因的表达可能参与甚至调控了棉株体防御或忍耐盐胁迫的过程。     

外源生长调节物质对甜高粱种子萌发过程中盐分胁迫的缓解效应及其生理机制

盐渍化土壤中盐胁迫是作物种子萌发和生长发育的主要限制因子, 探究盐分胁迫下提高种子萌发率的技术及机制对开发利用盐碱地有重要意义。本文以不同耐盐能力的高粱品种国甜2011和国甜106为材料, 研究了盐分对甜高粱种子萌发期生长过程的影响, 并比较了耐盐性差异。以耐盐性弱的国甜106为试材, 探究盐分胁迫下不同生长调节物质[γ-氨基丁酸(GABA)、赤霉素(GA₃)、激动素(KT)和水杨酸(SA)]对甜高粱种子吸水萌发过程中生长特性的调节效应。表明, 盐分胁迫显著抑制种子的吸水萌发, 降低种子的吸水速率、发芽势、发芽率、发芽指数, 增加种子的相对盐害率和丙二醛(MDA)含量。外源生长调节物质可有效缓解盐害, 显著增加种子的吸水率、发芽率、可溶性糖含量、可溶性蛋白含量, 提高SOD (超氧化物岐化酶)、POD (过氧化物酶)、CAT (过氧化氢酶)的活性, 促进K ⁺、Ca ²⁺、Mg ²⁺离子的吸收, 降低Na ⁺和MDA含量。外源生长调节物质主要是通过提高保护酶活性、渗透调剂物质含量和维持体内离子平衡来提高耐盐性。GA₃和GABA对盐害的缓解效应较好, 而KT促进种子对Mg ²⁺的吸收效果较好。本研究表明外源生长调节物质(尤其是 GA₃和 GABA)可用于盐碱地高粱生产, 为减轻盐碱地对高粱的盐碱胁迫提供了理论依据。     

盐胁迫对植物生长的影响及耐盐生理机制研究进展

盐胁迫是影响植物生长发育及产量的主要非生物胁迫,目前,中国盐渍土面积不断增大,培育耐盐作物、开发利用耐盐植物资源,是抵御盐胁迫的一种可行途径。盐胁迫对植物具有多方面的影响,盐胁迫下植物自身也会产生一系列生理生化的改变以调节离子及水分平衡,维持植物正常的光合作用。本综述从植物生长发育、光合作用、离子平衡等方面概括总结了盐胁迫对植物的影响,系统地介绍了植物自身通过离子区室化、清除活性氧、增强保护酶活性等来抵御盐害的生理机制。旨在培育耐盐作物、研究植物耐盐机理、开发利用耐盐植物资源、有效利用盐碱地等方面提供帮助,为农业发展、粮食安全以及生态环境安全提供参考依据。     

转Bt基因抗虫棉和有色棉苗期耐盐性差异研究

盐胁迫可致棉叶萎焉 ,叶温升高 ,气孔导度、蒸腾强度和光合速率降低 ,促进膜脂过氧化、丙二醛 (MDA)积累。但棉株体通过保护酶活性的提高和协同作用 ,以及盐离子的区域化分布 ,表现出较强耐盐胁迫的能力。耐盐性因基因型而异 ,在供试材料中 ,棕色棉和绿色棉的耐盐性最强 ,转 Bt基因抗虫棉 3 3 B和 S6 1 77的耐盐性最差。基因型间耐盐性差异与保护酶活性和盐离子在叶片中积累量的差异有关。长期人为选择可致棉花抗逆性的部分丢失 ,Bt基因的导入也可能影响棉花耐盐性的表达。     

棉花耐盐性的SSR鉴定研究

土壤盐碱化现已成为危害农业发展和生态环境的全球性问题,培育和鉴选棉花耐盐品种是合理开发利用盐碱地的有效途径。本研究选用25份耐盐(包括耐和抗)和23份盐敏感棉花种质为实验材料,采用SSR技术,展开了棉花耐盐性鉴定技术的有关研究。从DNA快速提取到PCR扩增和产物检测以及多标记组合鉴定等环节进行分析探讨,初步制定了一套适于棉花耐盐性分子鉴定的方法,即多标记组合鉴定法。并用11份材料对该方法进行了验证,结果表明和0.4%盐量胁迫法的鉴定结果的相符率达90.91%。初步研究结果表明多标记组合鉴定法可用于棉花耐盐分子标记辅助鉴定。     

水稻耐盐性的遗传和分子育种的研究进展

盐胁迫是造成水稻减产的重要环境因素之一。本文从维护膜系统的完整性、离子的区隔化以及渗透调节等三个方面介绍了水稻耐盐性的机理;简要描述了水稻生物耐盐能力、农艺耐盐能力和离体细胞对盐害反应等三种耐盐鉴定方法。总结了近年来对水稻耐盐种质资源的发掘、耐盐性QTL定位和重要基因的克隆以及耐盐水稻选育所取得的进展。通过长期水稻耐盐性评价、已发掘了一些耐盐的水稻种质;定位了七十多个控制Na+/K+含量、存活天数等耐盐性相关性状的QTL;两个水稻耐盐基因SKC1和DST已被克隆;我们已获得系列不同程度耐盐的转基因植株和SKC1/BADH两类耐盐基因聚合系。本文进一步讨论了水稻耐盐性机制的研究以及在生产实践中应用的前景,试图为深入开展水稻耐盐性研究提供参考。     

棉花植株和花粉耐盐性的鉴定

本研究对８个耐盐性不同的棉花品种（系），利用水培的方法对其整体植株进行了耐盐性鉴定，利用液滴培养技术对其花粉的耐盐性进行了鉴定，并分析了棉花整体植株和花粉耐盐性的相关性，结果表明，在水培盐胁迫条件下，棉花叶片总面积和叶片鲜重减少的百分数是反映棉花整体植株耐盐性的指标。在液滴培养盐胁迫条件下，棉花花粉粒萌发的百分率是反映其耐盐性的可靠指标，而花粉管的长度不能反映棉花的耐盐性。棉花整体植株的耐盐性和花     

山菠菜胆碱单加氧酶基因对棉花的遗传转化和耐盐性表达

胆碱单加氧酶（CMO）是渗透保护剂甜菜碱生物合成的关键酶之一。以棉花（Gossypium hirsutium L.）泗棉3号的下胚轴切段为外植体，利用农杆菌介导法将克隆自山菠菜（Atriplex hortensis）的AhCMO基因导入其中，通过组织培养胚状体发生途径获得转基因再生植株。以0.5%卡那霉素对再生苗筛选后，PCR检测抗卡那霉素棉苗确认阳性转化株，Southern和Northern杂交结果进一步证实外源基因已导入棉花并得到表达。在温室盆栽条件下，于2片真叶期对转AhCMO基因棉花及其转化受体泗棉3号施加0.5%的NaCl胁迫，15 d后发现其光合作用和植株生长被显著抑制，非转基因棉花泗棉3号的株高、鲜重和光合速率分别降低了57.6%、65.6%和69.9%，而转AhCMO基因的棉株分别降低了37.3%、54.6% 和47.9%。转AhCMO棉花所受盐害程度显著小于非转基因的棉株，说明AhCMO基因的导入和表达提高了转基因棉花的耐盐性。     

Ionic Homeostasis and Expression of Na+ Related Genes of Cotton under Different Salt and Alkali Stresses

[Objective] Maintaining intracellular ion homeostasis is one of the important salt-tolerant mechanisms of crops. This study aims to analyze differences in response characteristics of cotton ionome and salt-tolerant gene expression under different saline-alkali stresses, which provides a basis for understanding the mechanism of salt tolerance and improving salt tolerance of cotton. [Method] Using Lumianyan 24 as the experimental material, three kinds of salt and alkali stress types (salt stress, alkali stress, and mixed salt-alkali stress) and two concentration gradients (low and high concentrations) were set under pot cultivation conditions. Meanwhile, non-saline-alkali stress treatment was set as control. The dry matter weight of cotton plants and root morphological parameters including root length, root surface area, and root volume were measured in this study. The concentrations of 13 elements such as P, Na, K, Ca and Mg in different organs of cotton plants were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The relative expressions of salt tolerance related genes GhDFR1, GhSOS1, GhNHX1 and GhAKT1 were determined by the quantitative real-time polymerase chain reaction method. [Result] 1) Salt and alkali stresses significantly inhibited cotton growth. The growth inhibition rate of cotton under mixed salt-alkali stress treatments (48.7%–57.9%) was significantly higher than that under salt stress (27.6%–49.9%) and alkali stress (21.2%–35.5%) treatments. Under salt stress and mixed salt-alkali stress treatments, both shoot and root growth of cotton were significantly inhibited, dry matter weight, root length, root surface area and root volume were significantly reduced, while root growth was less inhibited under alkali stress treatments. 2) Under three types of saline-alkali stresses, Na content and Mo content in different organs of cotton plant increased significantly, but N content in leaves and roots decreased. 3) Under salt stress treatments, the uptake of Ca, Mg, Fe, Mn and Zn in cotton was inhibited, and the ion balance was maintained by promoting the transport of these ions and P, K. 4) In addition to Ca, Mg, Fe, Mn and Zn, P uptake was also inhibited under alkali stress treatments, but K uptake and P, K, Ca, Mg, Fe, Mn and Zn transport were promoted. 5) Under mixed salt-alkali stress treatments, especially under high salinity and pH conditions, most of nutrients uptake was inhibited, and the transport capacity of Ca, Mg, Zn, Mn and Fe was reduced. 6) The relative expression of GhSOS1 and GhAKT1 genes increased significantly under salt stress treatments, but increased first and then decreased under alkali stress and mixed salt-alkali stress treatments. The relative expression levels of GhSOS1 and GhAKT1 genes under three types of saline-alkali stresses were alkali＞salt＞mixed saline-alkali stress. With the increase of soil salinity and pH value, the relative expression of GhNHX1 gene increased first and then decreased. The expression levels of GhNHX1 gene were salt＞alkali＞mixed salt-alkali stress. [Conclusion] Due to high salinity and pH value, mixed salt-alkali stress significantly inhibits cotton growth and ions uptake, which restricts the transport of P, K, Ca, Mg, Zn, Mn and Fe. The decrease of K and Na regulation ability leads to ions imbalance.     

Genetic variation in salt tolerance at the seedling stage in an interspecific backcross inbred line population of cultivated tetraploid cotton

Soil salinity reduces cotton growth, yield, and fiber quality and has become a serious problem in the arid southwestern region of the Unites States. Development and planting of salt-tolerant cultivars could ameliorate the deleterious effects. The objective of this study was to assess the genetic variation of salt tolerance and identify salt tolerant genotypes in a backcross inbred line (BIL) population of 142 lines from a cross of Upland (Gossypium hirsutum) × Pima cotton (G. barbadense) at the seedling growth stage. As compared with the non-saline (control) conditions, seedlings under the salinity stress (200 mM NaCl) showed a significant reduction in all the plant growth characteristics measured, as expected. Even though the two parents did not differ in salt response as measured by percent reduction, significant genotype variations in the BIL population were detected for all traits except for leaf number. Based on percent reduction of the traits measured, several BILs were more salt tolerant than both parents. The results indicate that transgressive segregation occurred during the process of backcrossing and selfing even though both parents were not salt tolerant during seedling growth. Coefficients of correlation between all the traits were significantly positive, indicating an association between the traits measured. The estimates of broad-sense heritability were 0.69, 0.46, 0.47, 0.43, and 0.49 for plant height, fresh weight of shoot and root, and dry weight of shoot and root, respectively, indicating that salt tolerance during cotton seedling growth is moderately heritable and environmental variation plays an equally important role. The overall results demonstrate that backcrossing followed by repeated self-pollination is a successful strategy to enhance salt tolerance at the seedling stage by transferring genetic factors from Pima to Upland cotton.     

盐胁迫下棉花K~+和Na~+离子转运的耐盐性生理机制

为了探究棉花的耐盐机制,以中棉所49、中棉所35和中51504为材料,研究了盐胁迫对棉花幼苗的生长及K+/Na+平衡生理的影响。结果表明,150 mmol·L-1 Na Cl处理对幼苗的生长具有明显抑制作用,降低了叶片的光合速率(Pn)、PSⅡ实际光量子产额(ΦPSII)和电子传递速率(ETR),增加了非光化学荧光猝灭系数(q N)。与中棉所49和中棉所35相比,中51504的干物质累积受盐胁迫影响最小,且保持较高的Pn、ΦPSII、ETR和q N值及较低的ETR/Pn值。盐胁迫提高了棉花组织中Na+的浓度,降低了K+的浓度;但中51504组织中保持了相对较低的Na+浓度和较高的K+浓度,维持了较高的K+/Na+比;通过非损伤微测技术(NMT)测定的离子流结果也表明,中51504的根系对Na+有较强的外排能力,而对K+有较强的保留和向地上部转运能力。能够有效地调节Na+和K+的跨膜转运进而维持K+/Na+平衡是棉花耐盐的重要生理机制之一。     

Improved salt tolerance and seed cotton yield in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) by transformation with <Emphasis Type="Italic">betA</Emphasis> gene for glycinebetaine synthesis

Homozygous transgenic cotton (Gossypium hirsutum L.) plants that accumulated glycinebetaine (GB) in larger quantities were more tolerant to salt than wild-type (WT) plants. Four transgenic lines, namely 1, 3, 4, and 5, accumulated significantly higher levels of GB than WT plants did both before and after salt stress. At 175 and 275 mM NaCl, seeds of all the transgenic lines germinated earlier and recorded a higher final germination percentage, and the seedlings grew better, than those of the WT. Under salt stress, all the lines showed some characteristic features of salt tolerance, such as higher leaf relative water content (RWC), higher photosynthesis, better osmotic adjustment (OA), lower percentage of ion leakage, and lower peroxidation of the lipid membrane. Levels of endogenous GB in the transgenic plants were positively correlated with RWC and OA. The results indicate that GB in transgenic cotton plants not only maintains the integrity of cell membranes but also alleviates osmotic stress caused by high salinity. Lastly, the seed cotton yield of transgenic lines 4 and 5 was significantly higher than that of WT plants in saline soil. This research indicates that betA gene has the potential to improve crop’s salt tolerance in areas where salinity is limiting factors for agricultural productivity.     

Reproductive Compensation of Cotton after Salt Stress Relief at Different Growth Stages

Differential salt sensitivity during growth stages and reproductive compensation of plants after salt stress relief are important factors for adopting appropriate irrigation strategies with saline waters. Consequently, recovery of cotton after exposure to different levels of salt stress was evaluated. An outdoor, sand culture experiment was conducted with cotton. Water salinities were 2, 10 and 20 dS m⁻¹, and the growth phases were vegetative (G1), reproductive (G2) and boll development (G3). G1 and G3 were the least and the most salt tolerant phases, respectively. The significant yield reduction in all of the saline water treatments as compared to control was mainly due to the reduction in number of bolls per plants. In general, cotton plants were capable of producing seed cotton under salt stress, as well as, after salt stress relief. However, as the salt stress severity increased the ability of cotton to compensate yield loss decreased. Irrigation of cotton at G1 stage with either moderate (10 dS m⁻¹) or high (20 dS m⁻¹) salinity waters should be avoided. Moderate saline water could be applied either at G2 or G3 stage. High salinity water can be used for irrigation only at G3 stage to produce acceptable cotton seed yield.     

转GHABF4转录因子棉花植株的耐盐性研究

AREB/ABFs转录因子家族基因主要参与干旱、高盐、低温等胁迫应答反应。为了获得具有较高耐盐水平的棉花新种质材料,通过农杆菌介导法将耐盐转录因子基因(GHABF4)导入陆地棉中棉35中,通过对转化植株的卡那霉素初步筛选及T1、T2、T3目的基因PCR的分子检测,获得T3转基因棉花纯合系。通过盐胁迫试验对5个T3转基因棉花株系和非转基因棉花对照进行耐盐性分析。结果表明,在200 mmol/L Na Cl胁迫下,与非转基因对照相比,5个转基因棉花株系株高提高2.5~4.4 cm,地上部分的鲜质量增加3.6%~11.8%;且抗氧化物酶SOD、POD、CAT活性以及叶绿素含量提高。在盐胁迫条件下,转GHABF4基因棉花表现出优良的生长和生理优势,转GHABF4基因能够提高棉花的抗盐能力。     

棉花苗期耐盐生理指标的筛选及综合评价

为了筛选与棉花耐盐密切相关的生理指标,为棉花苗期耐盐鉴定提供理论依据。以4个棉花品种为材料,通过塑料盒栽植试验,探讨了棉花幼苗在盐胁迫前和胁迫后5天、10天、15天时的叶片相对含水量、质膜透性、游离脯氨酸含量、丙二醛含量、K+、Na+及K+/Na+值等耐盐相关生理指标相对值的变化情况,利用方差分析、主成分分析和隶属函数分析等方法对数据进行统计分析。结果表明所有指标在胁迫后第5天开始即与胁迫前表现极显著差异;选取K+/Na+值、相对含水量和质膜透性3个主要的耐盐鉴定生理指标;4个棉花品种的耐盐性强弱排序为‘枝棉3号’>‘中棉所35’>‘鲁棉6号’>‘中棉所12’。胁迫后第5天为最佳鉴定时机,所选取的耐盐生理指标代表了所有指标的信息,且其评价结果与省地方标准《棉花耐盐性鉴定评价技术规范》中盐害指数的评价结果高度相关,因此所选生理指标可与隶属函数法相结合用于棉花苗期耐盐综合评价中。