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1.
Abstract

Wheat is the main source of carbohydrates and amino acids consumed in the world. Amino acids and other physiological characters were determined in six wheat genotypes viz. IBWSN-1010, IBWSN -1025, TD-1, ESW-9525, Khirman and Chakwal-86 for pot experiment, to evaluate the response of genotypes under water stress at Nuclear Institute of Agriculture (NIA), Tandojam, Sindh, Pakistan, during 2018. Eight different physiological indices (Proline content, glycine-betaine, total sugars, total chlorophyll, nitrate reductase activity (NRA), potassium (K+) content, osmotic potential (OP) and relative water content (RWC)) were determined. The variance of analysis shows two-way interaction one with water stress [Control (normal four irrigations) and the other with terminal drought (Soaking dose) having significance at p?≤?0.05. It was observed that, ESW9525, IBWSN-1010 and IBWSN-1025 exhibited the tolerance followed by, Khirman and Chakwal-86 by maintaining their OP and accumulation of higher proline and glycine-betaine content. Whereas, moderate total soluble sugars were found in these genotypes. However, NRA increased in IBWSN-1010 enhancing tolerance under water stress.  相似文献   

2.
A deep understanding of crop-water eco-physiological relations is the basis for quantifying plant physiological responses to soil water stress. Pot experiments were conducted to investigate the winter wheat crop-water relations under both drought and waterlogging conditions in two sequential growing seasons from 2000 to 2002, and then the data were used to develop and validate models simulating the responses of winter wheat growth to drought and waterlogging stress. Thee xperiment consisted of four treatments, waterlogging (keep 1 to 2 cm water layer depth above soil surface), control (70%-80% field capacity), light drought (40%-50% field capacity) and severe drought (30%-40% field capacity) with six replicates at five stages in the 2000-2001 growth season. Three soil water content treatments (waterlogging, control and drought) with two replicates were designed in the 2001-2002 growth season. Waterlogging and control treatments are the same as in the 2000-2001 growth season. For the drought treatment, no water was supplied and the soil moisture decreased from field capacity to wilting point. Leaf net photosynthetic rate, transpiration rate, predawn leaf water potential, soil water potential, soil water content and dry matter weight of individual organs were measured. Based on crop-water eco-physiological relations, drought and waterlogging stress factors for winter wheat growth simulation model were put forward. Drought stress factors integrated soil water availability, the sensitivity of different development stages and the difference between physiological processes (such as photosynthesis, transpiration and partitioning). The quantification of waterlogging stress factor considered different crop species, soil water status, waterlogging days and sensitivity at different growth stages. Data sets from the pot experiments revealed favorable performance reliability for the simulation sub-models with the drought and waterlogging stress factors.  相似文献   

3.
This study aims to explain the effects of silicon (Si) foliar application on gas exchange characteristics, photosynthetic pigments, membrane stability and leaf relative water content of different wheat cultivars in the field under drought stress conditions. The experiment was arranged as a split-split plot based on randomized complete block design with three replications. Irrigation regime (100%, 60%, and 40% F.C.), silicon (control and Si application) and wheat cultivars (Shiraz, Marvdasht, Chamran, and Sirvan) were considered as main, sub and sub-sub plots, respectively. This study was carried out at the Research Farm of the Collage of Agriculture, Shiraz University, Iran, during 2012–2013 growing season. The results showed that foliar application of silicon increased the leaf relative water content, photosynthesis pigments (chlorophyll a, b and total chl and carotenoids), chlorophyll stability index (CSI) and membrane stability index (MSI) in all wheat cultivars, especially in Sirvan and Chamran (drought tolerant cultivars), under both stress and non-stress conditions. However, more improvement was observed under drought stress as compared to the non-stress condition. In contrast, these parameters decreased under drought stress. Si significantly decreased electrolyte leakage in all four cultivars under drought stress conditions. Furthermore, the intercellular carbon dioxide (CO2) concentration (Ci) increased under drought stress. Si application decreased Ci especially under drought stress conditions. Net photosynthesis rate (A), transpiration rate (E) and stomatal conductance (gs) were significantly decreased under drought conditions. Under drought, Si applied plants showed significantly higher leaf photosynthesis rate, transpiration rate, and stomatal conductance. Intrinsic water use efficiency (WUEi) and carboxylation efficiency (CE) decreased in all cultivars under drought stress. However, the silicon-applied plants had greater WUEi and CE under drought stress. The stomatal limitation was found to be higher in stressed plants compared to the control. Exogenously applied silicon also decreased stomatal limitation. Overall, application of Si was found beneficial for improving drought tolerance of wheat plants.  相似文献   

4.
ABSTRACT

Drought tolerance is a complex trait that involves different biochemical and physiological mechanisms in plants. It was the objective of the present study to evaluate the agronomic and biochemical responses of triticale, tritipyrum, and wheat to drought stress. For this purpose, twenty-seven genotypes were evaluated under two levels (non-stress and drought stress) of irrigation during 2015?2017. The metabolic traits studied included relative water content (RWC), membrane stability index (MSI), chlorophyll a (Chla), chlorophyll b (Chlb), carotenoids (Car), leaf proline content (Pro), leaf soluble carbohydrates (LSC), glycine betaine (GB), malondialdehyde (MDA), hydrogen peroxide (H2O2), seeds per spike (SS), seed weight (SW), biological yield (BY) and seed yield (SY). Drought stress increased Pro, LSC, and GB contents as well as lipid peroxidation through increasing MDA and H2O2 activities. However, both RWC and MSI indices as well as SS, SW, SY and BY reduced as a result of drought treatment although the least decrease of SY was observed at triticale group. During the two years of study, the tritipyrum genotypes exhibited their drought tolerance by accumulation of more LSC and GB as well as lower decrease in SW while the triticale ones responded by maintaining higher levels of RWC but producing less MDA and H2O2. It may, therefore, be concluded that the three species studied exploit different mechanisms to maintain tolerance against drought stress. Finally, correlation analysis indicated the positive effects of LSC on SY under both drought and normal conditions, which is obviously a promising trait in wheat, triticale, and tritipyrum that can be beneficially exploited in drought tolerance improvement programs.  相似文献   

5.
砧木的抗旱能力直接影响桃品种生长发育,选择适宜抗旱性桃砧木对桃产业发展有积极的促进作用。为阐明不同桃砧木对干旱胁迫生理响应机制,以5种桃砧木扦插苗为试材,通过盆栽控水方式,研究不同程度干旱胁迫下5种桃自根砧的叶片水分特性、渗透调节物质、抗氧化物酶及叶绿素含量变化。结果表明,随着干旱程度加重,5种砧木相对含水量、临界含水量下降,自然饱和亏、临界饱和亏及需水程度上升,组织密度和自由水含量逐渐减少,束缚水含量则增大,持水能力、组织水势和耐旱系数下降。各干旱胁迫处理的丙二醛(MDA)含量、 游离脯氨酸(Pro)含量、可溶性糖含量和叶绿素含量均增加;过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性提高,其中随干旱程度加重,丙二醛(MDA)含量、游离脯氨酸(Pro)含量均呈增加趋势,SOD活性、CAT活性也均呈提升趋势,可溶性糖含量、叶绿素含量、POD活性变化不尽相同。综合隶属函数分析可知,桃自根砧品种间抗旱性由强到弱依次为樱桃李5号、RA、樱桃李3号、GF677、樱桃李1号。  相似文献   

6.
Role of exogenously-applied silicon (Si) on antioxidant enzyme activities was investigated in wheat under drought stress using a completely randomized factorial design with four replications. Drought stress significantly enhanced activities of ascorbate peroxidase, peroxidase, superoxide dismutase and catalase, and elevated accumulation of osmotically active molecules, soluble sugars and proline. Si application further enhanced activities of enzymes involved in oxidative defense system and accumulation of osmotically active molecules in drought-stressed plants. Under drought stress conditions, water shortage decreased protein content in all cultivars; however, application of Si increased it. Pollen area ratio was lower than 1 for cvs. Shiraz and Marvdasht under drought, but greater than 1 for cvs. Chamran and Sirvan. Water-limited regimes resulted in decreased leaf Ψw in all cultivars, but Si supply was effective in improving Ψw under water-limited regimes. Water shortage increased leaf K, Mg, and Ca concentrations. Under drought stress, Si-treated plants had higher K concentration than the none-treated plants.  相似文献   

7.
盆栽试验结果表明,高粱和玉米2种作物均存在渗透调节和抗氧化耐旱途径。高粱耐旱性较强,干旱条件下叶片相对含水量较高,水势亦较大。高粱以可溶性糖和蛋白质为主要渗透调节物质,以过氧化氢酶(CAT)为主要抗氧化酶。玉米以K 和脯氨酸为主要渗透调节物质,以超氧化物歧化酶(SOD)和过氧化物酶(POD)为主要抗氧化酶。  相似文献   

8.
ABSTRACT

Drought is a major factor threatening crop production worldwide. Developing wheat varieties that are adapted to drought prone environments is a sustainable strategy to improve wheat production and productivity. The aim of this study was to evaluate and select bread wheat genotypes for yield and yield components, and for stability under drought stress and non-stress conditions. One hundred and twenty genotypes were evaluated at five test sites in the 2018/19 cropping season using a 10 x 12 alpha lattice design with two replicates. The level of drought stress was imposed using different sowing dates (early planting representing non-stressed, while late planting as drought stressed conditions) following the onset of the main rain at each site. Grain yield and yield components were recorded, and drought indices were calculated for each genotype. Among the drought tolerance indices, GMP, MP, HM, STI and YI were found to be the most suitable for predicting drought tolerance because they had significant and positive correlations with yield under drought stress and non-stress conditions. Rank sum analysis identified the most drought tolerant genotypes as ‘YS-34', ‘YS-85' and ‘YS-82’. The selected wheat genotypes are useful genetic resources for future drought tolerance breeding programmes in Ethiopia or similar agro-ecologies.  相似文献   

9.
The objective of this study was to determine drought tolerance characteristics of dryland wheat genotypes based on leaf gas exchange and water-use efficiency in order to identify promising genotypes for drought tolerance breeding. Physiological responses of ten genetically diverse wheat genotypes were studied under non-stressed (NS) and water stressed (WS) conditions using a 2?×?10 factorial experiment replicated 3 times. A highly significant water condition?×?genotype interaction (P?<?0.001) was observed for photosynthetic rate (A), ratio of photosynthetic rate and internal CO2 concentration (A/Ci), ratio of internal and atmospheric CO2 (Ci/Ca), intrinsic (WUEi) and instantaneous (WUEinst) water-use efficiencies suggesting genotypic variability among wheat genotypes under both test conditions. Principal component analysis (PCA) identified three principal components (PC’s) under both test conditions accounting for 84% and 89% of total variation, respectively. Bi-plot analysis identified G339 and G344 as drought tolerant genotypes with higher values of A, T, gs, A/Ci, WUEi and WUEinst under WS condition. The current study detected significant genetic variation for drought tolerance among the tested wheat genotypes using physiological parameters. Genotypes G339 and G344 were identified to be drought tolerant with efficient A, T, gs, A/Ci and water-use under water stressed condition.  相似文献   

10.
To evaluate the response of some selected wheat cultivars to silicon application at different growth stages under drought stress, an experiment was carried out in the greenhouse of College of Agriculture, Shiraz University, Iran, during 2012 using a completely randomized factorial design with four replications. Experimental treatments included drought stress (100% F.C. as control and 40% F.C. as drought) and foliar application of 6 mM sodium silicate (control, application at mid tillering stage, at anthesis stage, and application at tillering + anthesis stages) and wheat cultivars (Sirvan and Chamran, relatively drought-tolerant, and Shiraz and Marvdasht, drought-sensitive cultivars). Drought stress significantly reduced chlorophyll content, leaf area, relative water content, grains per spike, 1000-grain weight, grain yield and biomass of all wheat cultivars. Furthermore, drought stress increased electrolyte leakage of the flag leaves of all cultivars. In contrast, foliar-applied silicon significantly increased these parameters and reduced electrolyte leakage. Furthermore, highest positive influence of silicon application was observed at combined use of silicon both at the tillering + anthesis stages in wheat plants under both stress and non-stress conditions. Significant differences were found in physiological responses among wheat cultivars. The drought tolerant cultivars (Sirvan and Chamran) had significantly higher growth and yield than those of drought sensitive cvs. Shiraz and Marvdasht under drought stress. In conclusion, foliar application of silicon especially at the tillering + anthesis stages was very effective in promoting resistance in wheat plants to drought conditions by maintaining cellular membrane integrity and relative water content, and increasing chlorophyll content.  相似文献   

11.
The accumulation of total soluble and cell wall-bound phenolics and total soluble proteins in Zea mays plants exposed to drought stress and foliar spray of salicylic acid (SA) at 10?4?mol/L and 10?5?mol/L was investigated. Drought stress was imposed at the four-leaf stage for 10 days (30–35% field capacity). Dehydration of maize leaves was accompanied by the accumulation of both total soluble and cell wall-bound phenolics, reduction in leaf relative water content (LRWC), and shoot and root growth attributes. Foliar spraying of SA further augmented the content of total soluble and cell wall-bound phenolics and total soluble proteins content under drought stress. SA ameliorated the adverse effects of drought stress on LRWC, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, root length and root area. The accumulation of both soluble and cell wall-bound phenolics by foliar spray of SA may be a mechanism related to SA-induced drought stress tolerance in maize. It was concluded that foliar spraying of SA at 10?5?mol/L can be highly economical and effective for modifying the effects of drought stress on maize at the four-leaf stage.  相似文献   

12.
硅对干旱胁迫下小麦幼苗生长及光合参数的影响   总被引：9，自引：1，他引：9  
采用溶液培养试验,以两个抗旱性不同的小麦品种:低抗的扬麦9号(Yangmai.9)和高抗的豫麦18(Yumai.18)为材料,用PEG6000(聚乙二醇6000,渗透势约为-0.589MPa)模拟干旱胁迫条件,研究了硅对干旱胁迫下小麦幼苗生长、光合作用及可溶性糖含量的影响。结果表明,干旱胁迫条件下,小麦幼苗的生长和光合作用显著受到抑制,加硅处理能有效地提高干旱胁迫条件下小麦幼苗的生长状况及光合作用,且1.0.mmol/L.Si处理的效果优于0.1mmol/L.Si处理。与不加硅处理相比,干旱胁迫条件下加硅处理后,小麦幼苗的鲜干重、叶片可溶性蛋白含量、净光合速率(Pn)、蒸腾速率(Tr)、水分利用率(WUE)和气孔限制值(Ls)均显著升高,叶绿素含量也有一定程度的升高;而气孔导度(Gs)和细胞间隙CO2浓度(Ci)显著下降,可溶性糖积累量也降低。因此,硅可显著提高小麦对干旱胁迫的抗性。  相似文献   

13.
[目的]明确外源芸苔素甾醇类化合物(brassinosteroids,BRs)中14-羟基芸苔素甾醇(14-hydroxylated brassinosteroid,14-HBR)对干旱胁迫下冬小麦穗花发育成粒的调控效果,为小麦大田生产减轻干旱胁迫危害提供技术支撑.[方法]以大穗型品种周麦16(ZM16)和多穗型品种豫...  相似文献   

14.
The phenotypic performance of a genotype is not necessarily the same under diverse agro-ecological conditions. Two commercial wheat cultivars and 33 wheat landrace varieties were selected for screening drought tolerance and the investigation of genotype × environment interactions (GEI). The study site experiences drought stress at reproductive stages. Fully irrigated along with two drought stress trials at early heading (EHS) and 50% heading stages (HDS) were performed in 2 years. The highest antioxidant and proline contents were accumulated under EHS. Reduction in cell membrane stability in EHS was 90.9% in 2011–2012. The lowest grain yield belonged to EHS (3.2 t ha?1) while the highest (6.8 t ha?1) was observed in the irrigated trial. GEI analysis indicated that the Pinthus’s coefficient was not an efficient index for screening GEI. Positive correlations were found between GEI parameters such as regression deviation, Wricke’s ecovalence and Shukla’s variance. Regression coefficients over trials ranged from 0.65 to 1.42, indicating genotypes had different responses to environmental changes. Regression models, GEI variances and grain yield showed that some varieties (KC4557, KC4862, KC3891, KC4495, and KC4633) had higher stability under drought stress and fully irrigated conditions and can be involved in breeding programs for drought stress tolerance.  相似文献   

15.
This experiment was conducted in a glasshouse at the Agricultural and Natural Resources Research Center of Zarghan, Iran, in 2016. Sixteen wheat genotypes were compared under four salinity levels [control, 50, 100, and 150 mM sodium chloride (NaCl)] in terms of grain yield, chlorophyll (SPAD), flag leaf area, Na+/K+ ratio, catalase, and peroxidase activities in a randomized complete block design with three replications. Overall, results indicated that apparently no single parameter or a specific group of parameters could be suggested as factors of the most responsive element to different salinity stress levels. In other words, the tolerance mechanism of wheat genotypes is a complex response of multiple factors as a network path. Furthermore, different salinity levels led to different responses of wheat genotypes, which were detectable by the results of the mean comparison and analysis of variance. These results also proved the influential effects of the genetic background on salinity response and tolerance of wheat genotypes. In addition, antioxidants acting as defense barriers against reactive oxygen species are very important constituents against salinity, since higher antioxidant activity leads to alleviate the oxidative stress caused by salinity. Higher osmolyte concentration regulating the selective uptake of useful ions can prevent excess accumulation of toxic ions, which contribute to salinity stress damages. A high variation related to the measured traits in this study under both normal and salinity stress conditions was achieved, which could be applied in screening and breeding programs for salinity stress tolerance. Moreover, the responses of different genotypes varied regarding the different traits; SU-0129 as a novel genotype has proved to be the best choice for further breeding research based on the overall traits and, in particular, grain yield and tolerance stress index.  相似文献   

16.
Chitosan and its components have beneficial effects on a wide variety of plant species. Yet, their effects on wheat plants under drought stress are not well known. So, a field experiment was laid out in order to evaluate the effect of chitosan nanoparticles (NPs) on wheat. The wheat seeds were sown in plots. Then, the chitosan NPs were added to them through soil and foliar application at tillering, stem elongation, and heading stages. Results indicated that the drought stress significantly decreased majority of the studied traits compared to the normal irrigation. Application of the NPs especially 90?ppm increased leaf area (LA), relative water content (RWC), chlorophyll content, photosynthesis rate, catalase (CAT), and superoxide dismutase (SOD) activities, yield, and biomass compared to the control. Finally, our results highlight that usage of the chitosan NPs especially 90?ppm can mitigate adverse effects of drought in the wheat under drought stress.  相似文献   

17.
氮肥、干旱胁迫、基因型差异对冬小麦吸氮量的效应   总被引：18，自引：3，他引：15  
用品种、氮肥、干旱胁迫3因素3水平完全均衡试验方案的盆栽试验,研究小麦吸氮量和抗旱性的氮素营养遗传特性。结果表明,小麦吸氮量具有明显的基因型差异,施氮量、干旱胁迫程度对小麦吸氮量有极显著的影响。小麦子粒、秸秆、地上部的吸氮量和相应的产量呈极显著的正相关。干旱胁迫能明显减少小麦的吸氮量,且减少的程度因品种不同而异。基因型差异对小麦吸氮量的效应又受氮肥用量的影响。在正常供水和干旱下．小麦子粒和秸秆的吸氮量随氮肥使用量、基因型差异而不同。在轻度干旱条件下,选用中抗品种和中等氮肥水平（如W2V2N1）组合,子粒产量和吸氮量最大;而在正常供水时,选用正常或低抗品种和高氮量水平（如W1V2N2或W1V3N1）组合较好。  相似文献   

18.
ABSTRACT

Common abiotic stresses in rain-fed rice areas like drought can occur at any phase of crop growth and may occur periodically. Variation in intensity and severity of drought requires the use of different rice varieties and different nutrient management strategies. This study evaluated the morphological and physiological response of contrasting rice cultivars (Rajalaxmi, IR64, and Sahbhagidhan) to various nutrient combinations under water sufficience and scarce conditions. Drought stress at vegetative stage significantly reduced tiller formation, dry matter remobilization, and photosynthesis, leading to around 41.6% yield reduction. The effect of drought stress was more evident in Rajalaxmi and IR64 by a yield reduction of 57.4% and 43.2% as against only 24.3% in Sahbhagidhan. The combined application of nutrients resulted in higher proline accumulation, chlorophyll and carbohydrate concentrations, and photosynthesis and antioxidant enzymes, ultimately better tolerance to drought. This is reflected in higher values of tolerance indices and low scores of leaf drying and leaf rolling, especially for Sahbhagidhan. The combined application of P, K, Ca, Zn, and Fe resulted in 52.9, 53.3, 48.9% higher yield over P or K application. Rice drought tolerance can be managed by combining breeding of drought-tolerant high yielding varieties with the proper application of fertilizer nutrients.  相似文献   

19.
This work aimed to assess the influences of soil salinity and drought stresses on grain quality characteristics of selected salt-tolerant genotypes differing in salinity tolerance in durum wheat. This study was conducted under control, drought, and saline field conditions in separate experiments during 2 years. A randomized complete block design with three replications was used for each experiment. The results showed significant effects of genotype and environmental conditions on all grain-quality related traits. Salt and drought stress caused the significant increment of grain protein content, wet and dry gluten contents, and sodium dodecyl sulfate (SDS) sedimentation volume. Thousand-grain weight, grain protein yield, and test weight reduced significantly under both salinity and drought stress conditions. Protein content showed positive correlation with wet gluten, dry gluten, SDS sedimentation, and volume and strong negative correlation with other traits. It is concluded that influence of salinity stress was greater than drought stress on grain protein yield and some other grain-quality-related traits.  相似文献   

20.
外源蔗糖对小麦幼苗耐盐性的影响   总被引：2，自引：0，他引：2  
本研究选取小麦品种"沧6001"(抗盐性品种)和"石4185"(盐敏感品种)为试验材料,采用水培方法,对加入蔗糖后两个小麦品种的耐盐性进行比较。结果表明,盐胁迫下,"沧6001"和"石4185"小麦根系生长均受到抑制,"石4185"根系受到抑制的程度大于"沧6001";蔗糖预处理可以显著缓解盐胁迫对根系生长的抑制作用。蔗糖预处理12 h后,"沧6001"和"石4185"的可溶性糖含量上升,与"石4185"相比,"沧6001"具有更高的可溶性糖水平,但是蔗糖预处理后"石4185"可溶性糖含量的增加量高于"沧6001"。H2DCFDA荧光探针检测和PI荧光染色检测结果表明,蔗糖预处理可有效降低盐胁迫下小麦幼苗体内活性氧累积水平,保护细胞膜的完整性并减小根尖细胞死亡率。蔗糖预处理可以提高小麦幼苗SOD和APX(P<0.05)、CAT活性(P>0.05)。本研究对于理解外源物质对小麦耐盐性影响的生理机制及筛选耐盐性的小麦品种具有指导意义。  相似文献   

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