甜菜幼苗叶片抗氧化系统对干旱胁迫的响应

以抗旱性不同的甜菜品种HI0466和KWS9454为供试材料,在不同水分处理条件下研究了甜菜抗氧化系统生理指标对苗期不同程度水分亏缺的响应机制及其与甜菜抗旱性的关系。结果表明:持续水分胁迫下甜菜幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等保护酶活性及抗氧化物质还原型谷胱甘肽(GSH)、抗坏血酸(AsA)含量基本呈现出先升高后下降的趋势,而类胡萝卜素(Car)含量逐步降低。由于抗旱甜菜品种在水分胁迫下各生理指标具有增幅大或降幅较小的特征,因此在胁迫加重时抗旱甜菜品种可维持较高的SOD、POD、CAT活性及Car、AsA含量,以降低膜质过氧化程度,使得其丙二醛(MDA)含量维持在较低水平,但在品种间差异明显。主成分分析结果表明,干旱胁迫条件下SOD、POD活性,MDA、AsA含量均可作为甜菜品种苗期抗旱性鉴定的有效生理指标。     

硼胁迫对不同类型西瓜活性氧代谢与抗氧化系统的影响

【目的】为了研究硼对不同类型西瓜活性氧代谢与抗氧化系统的影响。【方法】以籽瓜、“黑美人”西瓜和野生西瓜为材料,设0.00,0.05,0.20,0.60 mmol/L 四个硼浓度,测定三种类型西瓜O2.?、H2O2和MDA含量及SOD、POD和CAT活性。【结果】结果表明：三种类型西瓜的O2和H2O2产生速率在硼胁迫下均显著提高,且高硼胁迫的西瓜O2.?和H2O2产生速率都大于缺硼胁迫,并导致MDA的积累。硼胁迫使三种类型西瓜的POD活性上升,CAT活性下降。籽瓜和“黑美人”的SOD活性下降,野生西瓜SOD活性上升。【结论】硼胁迫引起西瓜的活性氧爆发,并启动了西瓜的抗氧化系统,但仍然无法完全抵御硼胁迫带来的活性氧伤害,野生西瓜对硼胁迫的抗逆最强。     

芦笋抗旱生理生化特性研究初报

用聚乙二醇(PEG-6000)胁迫芦笋幼苗，检测幼苗的渗透调解物质含量、生物膜透性、抗氧化特性，结果表明：脯氨酸、可溶性糖含量随着处理时间的延长显著增加，且以20%的PEG浓度处理增加最明显；SOD、POD、CAT活性在PEG处理后也明显增强，但不同浓度处理之间差异不显著；相对电导率随着处理浓度的增大和时间的延长而增大；MDA含量随着处理时间的延长明显增加，且以10%和20%浓度处理增加显著。由此说明，芦笋在干旱胁迫下通过增加渗透调解物质含量，降低水势，提高保水力来提高其抗旱能力;通过增强抗氧化酶活性，提高抗氧化能力，是减轻干旱胁迫伤害机理之一。     

干旱及复水条件下转基因甘薯抗氧化防御系统特性

以转铜锌超氧化物歧化酶（Cu/Zn SOD）和抗坏血酸过氧化物酶（APX）基因甘薯(TS)及未转基因甘薯(NT)为实验材料,研究在旱后复水条件下转基因甘薯及未转基因甘薯抗氧化防御系统变化。结果显示,连续36h胁迫条件下,TS和NT的SOD活性都先降低后升高,但TS的SOD活性始终高于NT。胁迫至24h时,TS的SOD活性约为NT的1.2倍,复水后二者SOD活性都下降。持续胁迫时,TS的APX活性先升高后降低,NT与之相反,复水后TS和NT的APX活性都是先升高后降低,复水12h,TS的APX活性是NT1.5倍。在水分胁迫条件下,TS抗氧化物质AsA、CAR增长速度较快,复水后,TS中的AsA含量仍显著高于NT水分胁迫条件下TS的膜质受伤害程度要轻于NT,胁迫24h,复水12h,NT的MDA含量均约为TS的1.2倍。实验结果表明,同时转入SOD、APX抗氧化基因后,在胁迫及复水条件下转基因甘薯的抗氧化系统可以更好的对植株体进行保护及修复。     

一氧化氮和亚甲基蓝对盐胁迫抗虫棉根系的抗氧化能力的影响

 通过检测抗氧化酶活性和抗氧化物含量,研究一氧化氮和亚甲基蓝对盐胁迫抗虫棉根系的抗氧化能力的影响。在正常条件和盐胁迫条件下分别用一氧化氮和亚甲基蓝处理抗虫棉幼苗,检测抗坏血酸(ASA)含量、抗坏血酸过氧化物酶(APX)活性、谷胱甘肽还原酶(GR)活性、谷胱甘肽(GSH/GSSG)值、脱氢抗坏血酸还原酶(DHAR)活性、单脱氢抗坏血酸还原酶(MDAR)活性,并作对比。结果表明：正常生长条件下添加NO能促进棉花幼苗生长,而添加亚甲基蓝(MB)显著抑制抗虫棉幼苗的生长;添加NO显著缓解了盐胁迫对棉花幼苗生长的抑制,提高了根系的抗氧化能力,盐胁迫下添加NO的同时添加MB可不同程度地降低以上抗氧化物质含量和抗氧化酶活力,解除NO对盐胁迫的促长作用。     

不同浓度Cd3+胁迫对小麦幼苗膜脂过氧化作用的影响

以小麦幼苗为试验材料,研究不同浓度的Cd3+对其膜脂过氧化及抗氧化系统的影响。结果表明,随着胁迫时间的延长,SOD活性和VC含量先升后降,但在同一胁迫时间里随着Cd3+处理浓度的升高,2者呈逐渐下降的趋势;随着胁迫时间的增加,CAT和POD活性逐渐降低,叶绿素和蛋白质含量也随之逐渐下降,而膜脂过氧化产物(MDA)过量积累,膜透性(电导率)逐渐增大,且电导率在45℃时大于室温的导电率。     

NaCl胁迫对高粱幼苗生理生化特性的影响

以河农16高粱的3叶期幼苗为材料,在不同浓度的NaC l溶液中胁迫处理,分别在处理1h、2h、3h和4h后取幼苗,研究不同NaC l浓度和不同胁迫时间对高粱幼苗渗透调节物质(可溶性蛋白、脯氨酸含量、可溶性糖含量)和抗氧化保护酶系统活性(POD、SOD、CAT)的影响。结果表明,在一定范围内,随NaC l浓度的升高和胁迫时间的延长,河农16幼苗的渗透调节物质含量增加,超过最大耐受范围后含量下降。抗氧化保护酶系活性变化与渗透调节物质变化相似,呈现先升后降的趋势。河农16幼苗在NaC l胁迫下,渗透调节物质和抗氧化酶系统对NaC l溶液的有效调节浓度为0.9%。     

甜菜碱预处理对盐胁迫下小麦幼苗类囊体膜脂脂肪酸组分和功能的影响

以2个小麦品系旱丰9703（抗旱性强）和山农215953（抗旱性弱）为材料，研究了对盐胁迫的反应，以及外源甜菜碱在提高小麦抗盐性方面的作用。结果表明，盐胁迫导致小麦幼苗类囊体膜脂脂肪酸组分相对含量发生改变，山农215953的磷脂酰甘油（PG）和磷脂酰胆碱（PC）中亚麻酸（18∶3）相对含量均显著下降，旱丰9703仅PC中亚麻酸（18∶3）相对含量显著下降。甜菜碱预处理能显著缓解盐胁迫导致的山农215953的PG和旱丰9703的PC中18∶3相对含量的下降。盐胁迫导致小麦幼苗类囊体Ca²⁺-ATPase活性、Hill反应活力和叶绿素含量及光合作用的降低，抗旱性较弱的山农215953下降程度较大；甜菜碱预处理能显著缓解其下降程度。抗旱性不同的小麦品系在抗盐性方面具有相同的趋势。     

湿地松优良半同胞家系保护酶活性及脂质过氧化作用对水分胁迫的生理响应

为研究湿地松优良半同胞家系保护酶及脂质过氧化作用对水分逆境的生理响应，采用盆栽试验和吸光度测定结合的方法，以普通湿地松种子为对照（CK），测定了七个湿地松半同胞家系在正常水分状态（土壤相对含水量为70%）、弱度水分胁迫（土壤相对含水量为55%~60%）、中度水分胁迫（土壤相对含水量为35%~40%）和强度水分胁迫（土壤相对含水量为20%~25%）条件下的SOD、CAT、AsA、MDA的含量和-O2产生速率，研究结果表明：无论是不同水分梯度还是不同家系水平，SOD、CAT、AsA活性和MDA含量的差异均达极显著水平，不同家系水平间-O2产生速率有显著差异，不同水分梯度间-O2产生速率差异达极显著水平。随着水分胁迫程度的加剧，SOD活性和MDA含量增加，二者呈显著线性关系；在水分胁迫初期，CAT活性缓慢增加，至水分胁迫后期，CAT活性增加较快；在水分胁迫初期，AsA活性缓慢增加，至胁迫中期，AsA活性上升较快并达到极大值，至胁迫后期，AsA活性急剧下降；在水分胁迫初期-O2产生速率缓慢下降，至胁迫中期下降幅度较大，至胁迫后期的严重水分胁迫时-O2产生速率略有上升，但此时还未达到胁迫初期的水平。表明在干旱逆境条件下，湿地松各家系体内的SOD、CAT和AsA协调正常运行，清除体内产生的MDA和活性氧等有害物质，避免活性氧和MDA的大量积累，维护其细胞功能性的完整，保护湿地松各家系生理代谢活动不受干扰而能正常生长发育，使其免受伤害。而湿地松半同胞家系与CK的SOD、CAT、AsA、MDA、-O2产生速率在品种之间没有明显的规律性，湿地松半同胞家系在水分胁迫下的保护酶也没有显著的保护优势     

白刺对干旱胁迫的生理生化反应

研究白刺幼苗抗旱特性的生理学机制,期望为干旱农业生产提供理论依据。实验采用盆栽,用控制浇水的方法对不同强度的干旱胁迫梯度上对白刺幼苗叶片相对含水量、丙二醛、脯氨酸、可溶性蛋白质、叶绿素含量、超氧离子自由基产生速率和抗氧化酶活性的变化特点进行了研究。试验结果表明：在干旱胁迫下,白刺叶片相对含水量降低、脯氨酸含量呈增加趋势;可溶性蛋白质、叶绿素含量在轻度和中度干旱胁迫时上升,在重度干旱胁迫时显著下降;随着干旱胁迫的加剧,膜透性上升,丙二醛含量和超氧离子自由基产生速率增加。抗氧化系统酶活性测定结果表明,SOD、POD、CAT 3个酶能配合协同作用,降低膜脂过氧化程度,减少水分胁迫造成的伤害。     

Vergleichende Streßphysiologie von Tepary-Bohnen (Phaseolus acutifolius A. Gray) als "Minor Crop" und Mwezi Moja-Bohnen (Phaseolus vulgaris, GLP 1004) als Hochleistungsleguminose im tropischen Landbau

Comparative stress physiology of tepary beans ( Phaseolus acutifolius ) as "minor crop" and mwezi moja beans ( Phaseolus vulgaris ) as high-yielding variety in tropical agriculture
The study deals with the ecophysiological demands of the "minor pulse" tepary beans ( Phaseolus acutifolius ) – possessing a high nutritional value – as well as of the high-yielding kenyan bean variety mwezi moja ( Phaseolus vulgaris, GLP 1004 ).
Special reference is dedicated on the drought resistance of the crops in order to make recommendations for potential cultivation in the semi-arid and arid drylands of South and Southeast Kenya.
Newly constructed growth containers gave possibilities to simulate different durations and intensities of water stress under controlled environmental conditions in climatic chamber experiments.
It was observed and recorded that teparies possess different mechanisms of morphological and physiological adaptation to high temperature and water stress, apparently including the ability of osmotic adjustment. The patterns of adaptation to water stress are combined with defined hydrature periods closely connected with the reduction of soil moisture.
There was no evidence of morphological adaptation of mwezi moja leaves to water stress. It was observed and recorded that there is a partial drought resistance within the upper leaf unit, apparently caused by osmotic adjustment.
The crop seems to be less adapted than tepary beans to marginal cropping areas (e.g. in agroecological zone, AE2, L 6 or LM 6; ace. to: J ätzold and S chmidt 1982/83) of the drylands due to high crop water requirements (about 30 % more than the "minor pulse"), low drought resistance and a high relative yield decrease under water stress – in spite of a short vegetation cycle (about 60–65 days).     

IR64背景耐旱导入系“PD29”分蘖期的抗逆生理特征

以轮回亲本IR64(籼稻)及旱稻材料IRAT109为对照, 系统分析了“PD29”在灌溉(对照)与干旱(胁迫)条件下的相关生理性状特征。研究发现, 遭遇干旱胁迫后, “PD29”植株能够维持较高的相对含水量(RWC)且胁迫后复水2 h该株系的RWC迅速恢复到饱和状态, 表明其具有较强的御旱能力。干旱条件下, “PD29”的PS II最大光化学效率(F_v/F_m)、渗透势(Y)、脯氨酸含量(Pro)、活性氧清除系统活性(AOA)均显著高于IR64, 且相对于灌溉处理, 其RWC, F_v/F_m的降低幅度显著低于IR64, 净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)的降幅, Pro及AOA的增幅均高于IR64。与IRAT109比较, 干旱逆境下“PD29”的Pro含量显著偏高且AOA平均增幅较高。因此认为, “PD29”的优良耐旱性表现与其在逆境下脯氨酸含量及活性氧清除系统活性的显著增强有关。另外, 干旱环境下的P_n、G_s及T_r的显著降低, 表明“PD29”的光合性能可塑性较强, 其光合性能在有利生长环境下能高效表达, 而在土壤水有限的环境下, 能够迅速降低以减少水分的进一步损失。     

干旱胁迫对盆栽“川丹参1号”生理指标及主要活性成分含量的影响

采用聚乙二醇（PEG-6000）对盆栽“川丹参1号”（CDS-1）模拟长期干旱胁迫,研究干旱胁迫对其生长情况、生理指标及主要活性成分积累的影响。结果表明,干旱胁迫显著降低CDS-1叶片中叶绿素含量,可溶性蛋白、可溶性糖和脯氨酸含量随干旱程度增加呈上升趋势,干旱胁迫下丙二醛含量显著增加,抗氧化酶（SOD、POD和CAT）活性随干旱胁迫程度增加而增加。活性成分分析表明,干旱胁迫后CDS-1根中酚酸和丹参酮类含量均有所上升,迷迭香酸和丹酚酸A含量在PEG-6000浓度为150g/L时最高,分别为CK的145%和175%,丹参酮类含量在PEG-6000浓度为50g/L时最高,增幅超60%。CDS-1在干旱胁迫下表现出适应性变化,轻度和中度干旱胁迫（PEG-6000浓度为50~100g/L）有利于CDS-1中酚酸和丹参酮类活性成分的积累,在实际生产中可通过科学控水保证和提高丹参药材的品质。     

Differential osmotic adjustment to iso-osmotic NaCl and PEG stress in the <Emphasis Type="Italic">in vitro</Emphasis> cultures of <Emphasis Type="Italic">Sesuvium portulacastrum</Emphasis> (L.) L.

The influence of iso-osmotic (−0.7 MPa) NaCl and PEG stress on growth, osmotic adjustment and antioxidant defense mechanisms was investigated in the in vitro cultures of Sesuvium portulacastrum (L.) L. The decreased relative growth rate (RGR) and water content of PEG-stressed calli in comparison to NaCl was found to be correlated with differences observed in the energy expenditure for the maintenance of osmotic balance. Osmotic adjustment in the NaCl-stressed calli favored higher accumulation of saline ions and soluble sugars, whereas PEG-stressed calli confirmed increased levels of organic osmolytes (proline, glycine betaine and soluble sugars). Permeability of Na⁺ ions across the membrane revealed increased relative electrolytic leakage (REL) in NaCl-stressed calli, however non-penetrating and highly viscous solution of PEG amplified the peroxidation of membrane lipids. Increased activities of superoxide dismutase and catalase displayed efficient removal of toxic reactive oxygen species in comparison to ascorbate peroxidase in the calli exposed to iso-osmotic stress. These findings suggest that differential tolerance potential to iso-osmotic NaCl and PEG stress in terms of osmotic adjustment appears to be the prime defense mechanism of Sesuvium for its survival under iso-osmotic stress conditions at the expense of reduced growth and water content.     

拔节和抽雄期水分胁迫对春玉米生长和产量的影响

本试验设置了三种水分处理，包括CK（整个生育期供水充足）、T1（从拔节期开始控水，持续不灌水直至生育期结束）、T2（从抽雄期开始控水，持续不灌水直至生育期结束），讨论水分胁迫对玉米生长和产量的影响。结果表明：玉米株高和叶面积指数对拔节期水分胁迫T1处理比较敏感，T2处理下的影响不是很显著；水分胁迫作用下营养器官积累的干物质对籽粒的贡献率显著下降，特别是叶片和茎秆积累的产物下降明显，叶鞘的干物质积累量仅对T1处理比较敏感；水分胁迫对玉米的穗部性状影响较大，最终导致T1、T2处理较CK处理减产62.8%和37.8%；水分胁迫作用下，对产量影响大小的因子排序为穗粒数>穗长>百粒重>干物质转运率>穗粗>叶面积指数>生物量。     

A method for testing drought tolerance in <Emphasis Type="Italic">Fragaria</Emphasis> based on fast screening for water deficit response and use of associated AFLP and EST candidate gene markers

Drought stress is one of the most important environmental factors that limit plant growth and development, thus reducing yield. The objective of the present research was to correlate the genetic structure of different Fragaria genotypes, as assessed by Expressed Sequence Tag (EST) and Amplified Fragment Length Polymorphism (AFLP) markers, and plant responses to drought stress. Firstly, physiological parameters related to the plant response to drought stress such as leaf relative water content (RWC) and water losing rate (WLR) were measured. WLR and RWC were compared for 20 cultivars of the octaploid Fragaria × ananassa, two ecotypes of the diploid species F. vesca and one octaploid species F. chiloensis. These parameters could discriminate genotypes showing a contrasting response to water stress. Secondly, AFLP and ESTs were compared in terms of their information content and efficiency in the study of genetic diversity and relationships among these 23 Fragaria genotypes. To evaluate the genetic basis for the observed variation in the measured physiological parameter, the effect of specific AFLP/EST loci on WLR and RWC for the different Fragaria genotypes was quantified by Kruskal–Wallis analysis. By Mantel testing, the hierarchical clustering of the Fragaria genotypes based on associated EST or AFLP markers was compared to the observed eco-physiological relevant grouping. A better discriminating capacity for associated markers was noted, enabling a functional marker selection approach to screen the strawberry gene pool for drought tolerance. Correlation of EST markers to leaf RWC and WLR enforces them as potential candidate genes in control of plant responses to drought stress in Fragaria sp.     

Water Stress Tolerance of Wheat (Triticum aestivum L.): Variations in Hydrogen Peroxide Accumulation and Antioxidant Activity in Tolerant and Susceptible Genotypes

An experiment was conducted on five wheat ( Triticum aestivum L.) cultivars, C 306, PBW 175 (tolerant to water stress), DL 153-2 (moderately tolerant to water stress), HD 2428 and HD 2329 (recommended for irrigated conditions, susceptible to water stress), under pot culture conditions to study the effect of water stress on oxidative injury and antioxidant activity. Water stress significantly decreased relative water content (RWC), ascorbic acid content and membrane stability, and increased hydrogen peroxide and malondialdehyde content, a measure of lipid peroxidation, and activities of antioxidant enzymes in all the genotypes at 7, 17 and 27 days after anthesis (DAA). Water stress tolerant genotypes C 306 and PBW 175, closely followed by DL 153-2, were superior to HD 2428 and HD 2329 in maintaining high RWC, ascorbic acid content and membrane stability and lower hydrogen peroxide content and lipid peroxidation (malondialdehyde content) under water stress at the three stages. The highest activities of glutathione reductase and catalase under water stress were observed in C 306, PBW 175 and DL 153-2 and the lowest activities in HD 2428 and HD 2329 at all the stages. Superoxide dismutase activity at all stages under irrigated conditions and at the first and second stages under water stress conditions did not show significant variation among the different genotypes, but at the last stage under water stress the enzyme activity was highest in C 306, closely followed by PBW 175 and DL 153-2, and lowest in HD 2428 and HD 2329. It is apparent that water stress induces an increase in hydrogen peroxide content and consequently lipid peroxidation and membrane injury (reduced membrane stability). The degree of oxidative stress and antioxidant activity seems to be closely associated with the tolerance/susceptibility of a genotype to water stress.     

Physiological and Biochemical Responses of Hexaploid and Tetraploid Wheat to Drought Stress

An experiment was conducted to investigate the physiological and biochemical responses of two hexaploids viz., C 306 (water stress tolerant) and Hira (water stress susceptible), and two tetraploids, HW 24 (Triticum dicoccum) and A 9‐30‐1 (Triticum durum) wheat genotypes to water stress under pot culture condition. Water stress was imposed for a uniform period of 10 days at 50, 60 and 70 days after sowing (DAS) and observations were recorded at 60, 70 and 80 DAS. Total dry matter and plant height were recorded at harvest. Water stress caused a decline in relative water content (RWC), chlorophyll and carotenoid content, membrane stability and nitrate reductase activity and increased accumulation of proline at all stages and abscisic acid (ABA) at 80 DAS in all the genotypes. Both the tetraploids showed a lower reduction in RWC and highest ABA accumulation under water stress. Among the hexaploids Hira showed the most decline in RWC and the lowest ABA accumulation. The tetraploids also showed comparatively higher carotenoid content and membrane stability, closely followed by C 306, while Hira showed the minimum response under water stress. Nitrate reductase activity and chlorophyll content under irrigated conditions were highest in Hira but under water stress the lowest per cent decline was observed in C 306, followed by HW 24, A 9‐30‐1, and Hira. Proline accumulation under water stress conditions was highest in hexaploids C 306 and Hira and lowest in tetraploids HW 24 and A 9‐30‐1. Tetraploids HW 24, followed by A 9‐30‐1 maintained higher plant height and total dry matter (TDM) under water stress and also showed a lower per cent decline under stress than hexaploids C 306 and Hira. From the results it is clear that proline accumulation did not contribute to better drought tolerance of tetraploids than hexaploids. It is also apparent that water stress tolerance is the result of the cumulative action of various physiological processes, and all the parameters/processes may not be positively associated with the drought tolerance of a particular tolerant genotype.     

Exogenous Glycinebetaine and Salicylic Acid Application Improves Water Relations, Allometry and Quality of Hybrid Sunflower under Water Deficit Conditions

Limited water availability hampers the sustainability of crop production. Exogenous application of glycinebetaine (GB) and salicylic acid (SA) has been found very effective in reducing the adverse effects of water scarcity. This study was conducted to examine the possible role of exogenous GB and SA application in improving the growth and water relations of hybrid sunflower ( Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation, viz. control (normal irrigations), water stress at budding stage (irrigation missing at budding stage) and water stress at flowering stage (FS) (irrigation missing at FS). GB and SA were applied exogenously at 100 and 0.724 m m respectively, each at the budding and FS. Control plants did not receive application of GB and SA. Water stress reduced the leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), leaf relative water contents, water potential, osmotic potential, turgor pressure, achene yield and water use efficiency. Nevertheless, exogenous GB and SA application appreciably improved these attributes under water stress. However, exogenous GB application at the FS was more effective than other treatments. Net assimilation rate was not affected by water stress as well as application of GB and SA. The protein contents were considerably increased by water stress at different growth stages, but were reduced by exogenous GB and SA application. The effects of water stress and foliar application of GB were more pronounced when applied at FS than at the budding stage. Moreover, exogenous GB application was only advantageous under stress conditions.     

Improving Drought Tolerance by Exogenous Application of Glycinebetaine and Salicylic Acid in Sunflower

Water shortage is a severe threat to the sustainability of crop production. Exogenous application of glycinebetaine (GB) and salicylic acid (SA) has been found very effective in reducing the adverse affects of drought stress. This study was conducted to examine the possible role of exogenous GB and SA application in improving the yield of hybrid sunflower (Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation, viz. control (normal irrigations), water stress at vegetative stage (irrigation missing at vegetative stage) and water stress at flowering stage (irrigation missing at flowering stage). GB and SA were applied exogenously at 100 and 0.724 mm , respectively, each at the vegetative and at the flowering stage. Control plants did not receive application of GB and SA. Water stress reduced the head diameter, number of achene, 1000‐achene weight, achene yield and oil yield. Nevertheless, exogenous GB and SA application significantly improved these attributes under water stress. However, drought stress increased the free leaf proline and GB, and were further increased by exogenous application of GB and SA. However, exogenous GB application at the flowering stage was more effective than other treatments. Oil contents were also reduced under water stress; however, GB and SA application could not ameliorate the negative effect of water stress on achene oil contents. The effects of water stress and foliar application of GB were more pronounced when applied at the flowering stage than at the vegetative stage. Moreover, exogenous GB application was only beneficial under stress conditions.