The average rainfall in whole growth period of winter wheat to plus or minus several times of sample variance was used to define different grades of drought.The reduction rate of production in meteorological which was...The average rainfall in whole growth period of winter wheat to plus or minus several times of sample variance was used to define different grades of drought.The reduction rate of production in meteorological which was equal to or greater than the rate of 3% was taken as standards to define wheat drought disaster years.The average reduction ratio of production in the wheat drought years in Hebei-Shandong-Henan was calculated.The frequency distribution rule of wheat in different drought disaster strength of winter wheat in Hebei-Shandong-Henan was analyzed.According to the conception and calculation method of drought disaster risk index of winter wheat,the regional distribution law of drought disaster risk index of winter wheat was analyzed.The division technical methods of winter wheat drought disaster risk zones in Hebei-Shandong-Henan under the irrigated conditions were put forward.Taking the average reduction rate of production in drought years,drought disaster risk index and precipitation of winter wheat in growth periods as indices,using the statistical analysis and overlay function of GIS,the production reduction risk of winter wheat caused by drought disaster in winter wheat zones of Hebei-Shandong-Henan was divided and evaluated.The risk evaluation of production reduction of winter wheat in different risk zones under different climate conditions was realized.The disaster prevention and mitigation measures of winter wheat drought were given.展开更多
[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were cho...[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were chosen and drought-tolerance degrees of wheat were graded and identified according to Winter-wheat Drought Tol- erance Evaluation Technical Standards （GB/T 21127-2007）, and harvest wheat grains underwent spectrum collection, with a full-spectrum analyzer, to establish a database. [Result] Based on qualitative analysis and full-spectrum correlation research, the coef- ficient of determination （RSQ） and cross-validation coefficient of determination （1-VR） were concluded at 0.697 5 and 0.600 2, showing near-infrared diffuse reflectance spectroscopy is of significant differences among wheat varieties and of significant or extremely significant correlation with drought-tolerance indices. [Conclusion] The re- search indicates that to evaluate drought-tolerance of wheat with near-infrared diffuse reflectance spectroscopy is a rapid and feasible way, which is simple, convenient without damages on grains, and of practical values for construction wheat drought-tol- erance evaluation index system and identification of breeding materials.展开更多
[Objective]The study aimed to assess and zone the drought risk of winter wheat in Anhui Province. [Method] The zoning factors were chosen from three aspects of disaster-causing factors,disaster-bearing bodies and envi...[Objective]The study aimed to assess and zone the drought risk of winter wheat in Anhui Province. [Method] The zoning factors were chosen from three aspects of disaster-causing factors,disaster-bearing bodies and environment conducive to drought,and then their data were standardized,rasterized and graded. Using analytic hierarchy process（ AHP）,we determined the weight of each index at various levels and then established the assessment models of drought intensity,sensitivity,vulnerability and resistance of winter wheat in the whole growth period and at heading and filling stage. Finally,the zoning map of drought risk for winter wheat in Anhui Province was obtained using the farmland data mask of Anhui Province. [Result]The drought risk of winter wheat in Anhui Province in the whole growth period and at heading and filling stage was divided into six grades,which reflected the distribution characteristics and regional difference of drought risk for winter wheat in Anhui Province. Drought risk was the maximum in the main producing areas of winter wheat in the north of Huaihe River,followed by the area along Huaihe River and the area between Yangtze River and Huaihe River,while the drought risk of winter wheat was very low in the south of Anhui Province. The drought risk of winter wheat was markedly affected by the sensitivity to drought,vulnerability and the drought resistance of winter wheat. [Conclusion] The research could provide scientific references for rational distribution of winter wheat and establishment of strategies for disaster prevention and mitigation.展开更多
In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier clim...In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier climate in the future. Predicting the yield loss due to an anticipated drought is crucial for wheat growers. A reliable way for predicting the drought-induced yield loss is to use a plant physiology-based drought index, such as Agricultural Reference Index for Drought (ARID). Since different wheat cultivars exhibit varying levels of sensitivity to water stress, the impact of drought could be different on the cultivars belonging to different drought sensitivity groups. The objective of this study was to develop the cultivar drought sensitivity (CDS) group-specific, ARID-based models for predicting the drought-induced yield loss of winter wheat in the Llano Estacado region in the southern United States by accounting for the phenological phase-specific sensitivity to drought. For the study, the historical (1947-2021) winter wheat grain yield and daily weather data of two locations in the region (Bushland, TX and Clovis, NM) were used. The logical values of the drought sensitivity parameters of the yield models, especially for the moderately-sensitive and highly-sensitive CDS groups, indicated that the yield models reflected the phenomenon of water stress decreasing the winter wheat yields in this region satisfactorily. The reasonable values of the Nash-Sutcliffe Index (0.65 and 0.72), the Willmott Index (0.88 and 0.92), and the percentage error (23 and 22) for the moderately-sensitive and highly-sensitive CDS groups, respectively, indicated that the yield models for these groups performed reasonably well. These models could be useful for predicting the drought-induced yield losses and scheduling irrigation allocation based on the phenological phase-specific drought sensitivity as influenced by cultivar genotype.展开更多
[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drou...[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drought resistance were selected and were classified according to their drought resistance grades determined by the Technical Specification of Identification and Evaluation for Drought Resistance in Wheat （GB/T 21127-2007）. In addition, the harvested wheat seed samples were spectrally analyzed with FOSS NIRSystems5000 near-infrared spectrum analyzer for grain quality （full spectrum analyzer） and then the forecasted regression equations were established. [Result] After the establishment of a database and validation, dis- criminated functions were obtained. The determination coefficient （RSQ） and coeffi- cients of determination for cross validation （1-VR） in the discriminant function built with seed samples from water stress area were 0.846 0 and 0.781 8, respectively, which indicated that the consistency between drought resistance and spectral charac- teristics in wheat varieties was good, and there was high correlation between the near-infrared diffuse reflectance spectra of seeds and the drought resistance in wheat. [Conclusiou] Under water stress condition, it is feasible to establish a conve- nient, rapid and no-damage identification system for the drought resistance in wheat by using the near-infrared diffuse reflectance spectrum technique to scan wheat seeds.展开更多
Under stress conditions such as droughthigh-salinity and low-temperature, the transcription factorof DREB (dehydration responsive element binding proteins)improved efficiently stress resistance by regulating the ex-pr...Under stress conditions such as droughthigh-salinity and low-temperature, the transcription factorof DREB (dehydration responsive element binding proteins)improved efficiently stress resistance by regulating the ex-pression of its downstream genes with various environmentastress resistance in plants. GmDREB gene (GenBank Acces-sion No. AF514908) encoding a stress-inducible transcriptionfactor was cloned by screening a cDNA library of Glycinemax cv. Jinong 27 with yeast one-hybrid method. GmDREBgene was 910 bp in length and encoded 174 amino acids con-taining a conserved AP2/EREBP DNA-binding domain of 58amino acids. Two conserved functional amino acids, valineand glutamic acid, were located on the 14th and the 19thamino acid residues in the conserved structural domain. Analkaline amino acid region (KKR) related to a nuclear local-ization signal was at the N-terminal, while an acidic aminoacid region (DDD) related to trans-activation was at theC-terminal. Plant expression vectors were constructed andtransformed into wheat by bombardment. In total, 13 trans-genic plants with Ubi::GmDREB and 11 transgenic plantswith rd29A::GmDREB were identified from 103 regenerationplants by molecular analysis. The drought and salt tolerancesof T1 transgenic lines with Ubi::GmDREB orrd29A::GmDREB were demonstrated to be improved ascompared to wild type. The result also suggested that bothUbiquitin and rd29A promoters could effectively drive theexpression of the GmDREB gene and enhance drought andsalt tolerance of T1 plants.展开更多
Triticum aestivum L. cv. Guizi 1(GZ1) is a drought-tolerant local purple wheat cultivar. It is not clear how purple wheat resists drought stress, but it could be related to anthocyanin biosynthesis. In this study, tra...Triticum aestivum L. cv. Guizi 1(GZ1) is a drought-tolerant local purple wheat cultivar. It is not clear how purple wheat resists drought stress, but it could be related to anthocyanin biosynthesis. In this study, transcriptome data from droughttreated samples and controls were compared. Drought slightly reduced the anthocyanin, protein and starch contents of GZ1 grains and significantly reduced the grain weight. Under drought stress, 16 682 transcripts were reduced, 27 766 differentially expressed genes(DEGs) were identified, and 379 DEGs, including DREBs, were related to defense response. The defense-response genes included response to water deprivation, reactive oxygen, bacteria, fungi, etc. Most of the structural and regulatory genes in anthocyanin biosynthesis were downregulated, with only Ta DFR, Ta OMT, Ta5,3GT, and Ta MYB-4 B1 being upregulated. Ta CHS, Ta F3H, TaCHI, Ta4CL, and TaF3’H are involved in responses to UV, hormones, and stimulus. Ta CHS-2D1, Ta DFR-2D2, Ta DFR-7D, TaOMT-5A, Ta5,3 GT-1B1, Ta5,3GT-3A, and Ta5,3GT-7B1 connect anthocyanin biosynthesis with other pathways, and their interacting proteins are involved in primary metabolism, genetic regulation, growth and development, and defense responses. There is further speculation about the defense-responsive network in purple wheat. The results indicated that biotic and abiotic stress-responsive genes were stimulated to resist drought stress in purple wheat GZ1, and anthocyanin biosynthesis also participated in the drought defense response through several structural genes.展开更多
Water stress treatment at different developmental stages of a winter wheat varietywas made in outdoor pot experiments from 1987 to 1988.It was found that the most sensitivestage was the booting stage and the second mo...Water stress treatment at different developmental stages of a winter wheat varietywas made in outdoor pot experiments from 1987 to 1988.It was found that the most sensitivestage was the booting stage and the second most sensitive stage was the flowering stage.Waterstress at most development stages affects the number of grains.Wheat water stress can be diag-nosed effectively and quickly by means of leaf temperature difference between the drought fieldand the well watered control plot measured by an infra-red thermometer.展开更多
Drought stress is one of the major factors affecting in wheat yield and grain quality. In order to investigate how drought stress might influence wheat quality during grain filling, three wheat cultivars Gaocheng 8901...Drought stress is one of the major factors affecting in wheat yield and grain quality. In order to investigate how drought stress might influence wheat quality during grain filling, three wheat cultivars Gaocheng 8901, Jagger and Nongda 3406 were subjected to drought stress during the grain filling stage. Neither globulin and glutenin, nor the relative percentage ofamylose significantly changed following drought treatments, whereas albumin and gliadin concentrations did. The SDS-sedimentation, which has a strong linear correlation with wheat baking quality was markedly decreased following drought stress. These results indicated that drought had an adverse effect on wheat qualit3,. In order to investigate the protein complexes in the wheat flour, the data from native PAGE and SDS-PAGE were combined and a total of 14 spots were successfully identified, and of these eight protein types were determined to be potential complex forming proteins.展开更多
The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatm...The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.展开更多
In wheat, the ear is one of the main photosynthetic contributors to grain filling under drought stress conditions. In order to determine the relationship between stomatal characteristics and plant drought resistance, ...In wheat, the ear is one of the main photosynthetic contributors to grain filling under drought stress conditions. In order to determine the relationship between stomatal characteristics and plant drought resistance, photosynthetic and stomatal characteristics and water use efficiency(WUE) were studied in two wheat cultivars: the drought-resistant cultivar ‘Changhan 58' and the drought-sensitive cultivar ‘Xinong 9871'. Plants of both cultivars were grown in pot conditions under well-watered(WW) and water-stressed(WS) conditions. In both water regimes,‘Changhan 58' showed a significantly higher ear photosynthetic rate with a lower rate of variation and a significantly higher percentage variation of transpiration compared to control plants at the heading stage under WS conditions than did ‘Xinong 9871' plants. Moreover,‘Changhan 58' showed lower stomatal density(SD) and higher stomatal area per unit organ area(A) under both water conditions. Water stress decreased SD, A, and stomatal width(SW), and increased stomatal length in flag leaves(upper and lower surfaces) and ear organs(awn, glume,lemma, and palea), with the changes more pronounced in ear organs than in flag leaves.Instantaneous WUE increased slightly, while integral WUE improved significantly in both cultivars. Integral WUE was higher in ‘Changhan 58', and increased by a greater amount, than in‘Xinong 9871'. These results suggest that drought resistance in ‘Changhan 58' is regulated by stomatal characteristics through a decrease in transpiration rate in order to improve integral WUE and photosynthetic performance, and through sustaining a higher ear photosynthetic rate, therefore enhancing overall drought-resistance.展开更多
Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein...Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein,105 wheat genotypes were screened against drought stress using factorial completely randomized design at seedling stage to determine the genetic diversity and traits association conferring drought tolerance.Analysis of variances revealed that all the studied parameters differed significantly among all genotypes,indicating the significance genetic variability existed among all genotypes for studied indices.The 10 best performance genotypes G1,G6,G11,G16,G21,G26,G39,G44,G51,and G61 were screened as drought tolerant,while five lowest performance genotypes G3,G77,G91,G98,and G105 were screened as drought susceptible.Root length,chlorophyll a,chlorophyll b,and carotenoid contents were significantly correlated among themselves which exhibited the importance of these indices for rainfed areas in future wheat breeding scheme.Shoot length exhibited non-significant and negative association with other studied traits,and its selection seems not to be a promising criteria for this germplasm for drought stress.Best performance genotypes under drought stress conditions will be useful in future wheat breeding program and early selection will be effective for developing high yielding and drought tolerant wheat varieties.展开更多
Drought is the most important factor limiting plant production in the majority of agricultural crops of the world. Wheat is generally grown on arid-agricultural fields. An experiment was conducted at the Plant physiol...Drought is the most important factor limiting plant production in the majority of agricultural crops of the world. Wheat is generally grown on arid-agricultural fields. An experiment was conducted at the Plant physiology research area, Agronomic Research Institute Faisalabad, during winter 2010-11 to evaluate the effect of drought on wheat variety Lasani 2008. The experiment was comprised of following treatments. T1 Normal moisture (3 IR at CRS, Booting and grain filling), T2 No irrigation (only rainfed) control, T3 water spray (100 ppm), T4 ascorbic acid (100 ppm), T5 salicylic acid (100 ppm), T6 calcium chloride (100 ppm), T7 glycinbetain (100 ppm). According to the resulting data the treatment in which three irrigation were applied produced more no. of tillers (52%), spikelet per spike (41%), spike length (30%), grain per spike (58%), grain yield (54%), biological yield (35%) as compared to control. The treatment in which no irrigation was applied produced less no. of tillers, spikelet per spike, spike length, grain per spike, grain yield, biological yield. Thousand grain weight and harvest index were non significant among all treatments.展开更多
The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and dec...The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and decrease of CO2 assimilation in flag leaf blade with water stress was more than that in ear. Compared with flag leaf, ear organs (awn, glume and lemma) had higher C4 enzyme activities and lower RuBPC activity. Under moderate water-stress, the increase of C4 enzyme activities was induced, and the increase was higher in ear than in flag leaf. Under severe water-stress, relatively higher C4 enzyme activities were still maintained in ear, rather than that in flag leaf. It suggests that high activities of C4 enzymes in ear may contribute to its high tolerance of photosynthesis to water-stress.展开更多
Recurrent drought associated with climate change is among the principal constraints to global productivity of wheat（Triticum aestivum（L.） and T. turgidum（L.））. Numerous efforts to mitigate drought through breedi...Recurrent drought associated with climate change is among the principal constraints to global productivity of wheat（Triticum aestivum（L.） and T. turgidum（L.））. Numerous efforts to mitigate drought through breeding resilient varieties are underway across the world. Progress is, however, hampered because drought tolerance is a complex trait that is controlled by many genes and its full expression is affected by the environment. Furthermore, wheat has a structurally intricate and large genome. Consequently, breeding for drought tolerance requires the integration of various knowledge systems and methodologies from multiple disciplines in plant sciences. This review summarizes the progress made in dry land wheat improvement, advances in knowledge, complementary methodologies, and perspectives towards breeding for drought tolerance in the crop to create a coherent overview. Phenotypic, biochemical and genomics-assisted selection methodologies are discussed as leading research components used to exploit genetic variation. Advances in phenomic and genomic technologies are highlighted as options to circumvent existing bottlenecks in phenotypic and genomic selection, and gene transfer. The prospects of further integration of these technologies with other omics technologies are also provided.展开更多
Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression （CTD）, the difference of air-canopy temperature, in screening wheat （Triticum aestivum L.） genot...Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression （CTD）, the difference of air-canopy temperature, in screening wheat （Triticum aestivum L.） genotypes for yield under dryland and irrigated. Forty winter wheat genotypes were grown under irrigation and dryland. CTDs were recorded after heading between 1 330 and 1 530 h on 6 clear days for dryland and 9 days for irrigation. Drought susceptible index （DSI） for each genotype was calculated using mean yield under dryland and irrigated conditions. Genotypes exhibited great differences in CTD under each environment. The dryland CTDs averaged 1.33℃ ranging from -0.67 to 2.57℃, and the average irrigation CTD were 4.59℃ ranging from 3.21 to 5.62℃. A low yield reduction was observed under dryland conditions relative to irrigated conditions for high-CTD genotypes. CTD values were highly negatively correlated with DSI under dryland, and genotypes of CTDs = 1.3℃ in dryland condition were identified as drought resistant. For 21 genotypes classified as drought resistant by DSI, their CTDs were 1.68℃ for dryland and 4.35℃ for irrigation on average; for 19 genotypes classified as drought susceptible by DSI, average CTD was 0.94℃ in dryland and 4.85℃ in irrigation. The high-yield genotypes consistently had high CTD values, and the low-yield ones had low CTD values for all measurements in dryland. After heading, genotypes maintained consistent ranking for CTD. Regression results for CTD and yield suggested that the best time for taking CTD measurement was 3-4 weeks after heading in irrigation but any time before senescence in dryland. Crop water stress index （CWSI） calculated from CTD data was highly correlated with CWSI calculated from yield, which suggesting traditional costly CWSI measurement may be improved by using portable infrared thermometers. Most importantly, grain yield was highly correlated with CTD under dryland （R^2 = 0.79-0.86） and irrigation （R^2 = 0.46-0.58） conditions. These results clearly indicated grain yield and water stress can be predicted by taking CTD values in field, which can be used by breeding programs as a potential selection criterion for grain yield and drought resistance in wheat, but a second study year is needed to confirm further.展开更多
Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic...Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic stress responses, in this study, we functionally characterized TaMIR1119, a miRNA family member of wheat （Triticum aestivum）, in regulating the drought adaptive response of plants. TaMIR1119 putatively targets six genes categorized into the functional classes of transcriptional regulation, RNA and biochemical metabolism, trafficking, and oxidative stress defense. Upon simulated drought stress, the TaMIR1119 transcripts abundance in roots was drastically altered, showing to be upregulated gradually within a 48-h drought regime andthat the drought-induced transcripts were gradually restored along with a 48-h recovery treatment. In contrast, most miRNA target genes displayed reverse expression patterns to TaMIR1119, exhibiting a downregulated expression pattern upon drought and whose reduced transcripts were re-elevated along with a normal recovery treatment. These expression analysis results indicated that TaMIR1119 responds to drought and regulates the target genes mainly through a cleavage mechanism. Under drought stress, the tobacco lines with TaMIR1119 overexpression behaved improved phenotypes,, showing increased plant biomass, photosynthetic parameters, osmolyte accumulation, and enhanced antioxidant enzyme （AE） activities relative to wild type. Three AE genes, NtFeSOD, NtCAT1;3, and NtSOD2,1, encoding superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） proteins, respectively, showed upregulated expression in TaMIR1119 overexpression lines, suggesting that they are involved in the regulation of AE activities and contribution to the improved cellular reactive oxygen species （ROS） homeostasis in drought-challenged transgenic lines. Our results indicate that TaMIR1119 plays critical roles in regulating plant drought tolerance through transcriptionally regulating the target genes that modulate osmolyte accumulation, photosynthetic function, and improve cellular ROS homeostasis of plants.展开更多
Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers...Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.展开更多
In order to study the effective water-saving cultivation of wheat in Sichuan under drought conditions to reduce grain loss,the effects of different irrigation methods（ natural rainfall,artificial irrigation,and infil...In order to study the effective water-saving cultivation of wheat in Sichuan under drought conditions to reduce grain loss,the effects of different irrigation methods（ natural rainfall,artificial irrigation,and infiltrating irrigation） on soil physical characteristics and main agronomic characters and yield of wheat were analyzed. The results showed that different irrigation treatments at different growth stages had different effects on soil physical characteristics and agronomic characters of wheat. At the seedling and jointing stage,there were small differences between the treatments in soil compactness,soil bulk density,and soil water content. At the flowering and maturation stage,different irrigation treatments had great impacts on soil compactness,soil bulk density,soil water content,and agronomic characters of wheat. In the hilly areas of Sichuan Basin,infiltrating irrigation at the jointing stage was the best,and wheat yield increased significantly,2 113. 46 kg/hm^2 higher than that in the control.展开更多
Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in...Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.展开更多
基金Supported by The Ministry of Finance,Meteorological Industry Spe-cific(GYHY200706030)China Meteorological Administration 2009 Budget Item(CMATG2009M32)~~
文摘The average rainfall in whole growth period of winter wheat to plus or minus several times of sample variance was used to define different grades of drought.The reduction rate of production in meteorological which was equal to or greater than the rate of 3% was taken as standards to define wheat drought disaster years.The average reduction ratio of production in the wheat drought years in Hebei-Shandong-Henan was calculated.The frequency distribution rule of wheat in different drought disaster strength of winter wheat in Hebei-Shandong-Henan was analyzed.According to the conception and calculation method of drought disaster risk index of winter wheat,the regional distribution law of drought disaster risk index of winter wheat was analyzed.The division technical methods of winter wheat drought disaster risk zones in Hebei-Shandong-Henan under the irrigated conditions were put forward.Taking the average reduction rate of production in drought years,drought disaster risk index and precipitation of winter wheat in growth periods as indices,using the statistical analysis and overlay function of GIS,the production reduction risk of winter wheat caused by drought disaster in winter wheat zones of Hebei-Shandong-Henan was divided and evaluated.The risk evaluation of production reduction of winter wheat in different risk zones under different climate conditions was realized.The disaster prevention and mitigation measures of winter wheat drought were given.
基金Supported by National Wheat Industry System(CARS-E-2-36)Henan Wheat Industry System(S2010-10-02)National Science and Technology Support Plan(2011BAD35B-03)~~
文摘[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were chosen and drought-tolerance degrees of wheat were graded and identified according to Winter-wheat Drought Tol- erance Evaluation Technical Standards （GB/T 21127-2007）, and harvest wheat grains underwent spectrum collection, with a full-spectrum analyzer, to establish a database. [Result] Based on qualitative analysis and full-spectrum correlation research, the coef- ficient of determination （RSQ） and cross-validation coefficient of determination （1-VR） were concluded at 0.697 5 and 0.600 2, showing near-infrared diffuse reflectance spectroscopy is of significant differences among wheat varieties and of significant or extremely significant correlation with drought-tolerance indices. [Conclusion] The re- search indicates that to evaluate drought-tolerance of wheat with near-infrared diffuse reflectance spectroscopy is a rapid and feasible way, which is simple, convenient without damages on grains, and of practical values for construction wheat drought-tol- erance evaluation index system and identification of breeding materials.
基金Supported by the Special Project for Meteorological Industry of Ministry of Science and Technology in 2010(GYHY201006027)Yearly Project of Anhui Science and Technology Agency in 2011(10021303032)Major Business Project of Anhui Meteorological Bureau in 2009"Zoning of Agricultural Climate in Anhui Province"
文摘[Objective]The study aimed to assess and zone the drought risk of winter wheat in Anhui Province. [Method] The zoning factors were chosen from three aspects of disaster-causing factors,disaster-bearing bodies and environment conducive to drought,and then their data were standardized,rasterized and graded. Using analytic hierarchy process（ AHP）,we determined the weight of each index at various levels and then established the assessment models of drought intensity,sensitivity,vulnerability and resistance of winter wheat in the whole growth period and at heading and filling stage. Finally,the zoning map of drought risk for winter wheat in Anhui Province was obtained using the farmland data mask of Anhui Province. [Result]The drought risk of winter wheat in Anhui Province in the whole growth period and at heading and filling stage was divided into six grades,which reflected the distribution characteristics and regional difference of drought risk for winter wheat in Anhui Province. Drought risk was the maximum in the main producing areas of winter wheat in the north of Huaihe River,followed by the area along Huaihe River and the area between Yangtze River and Huaihe River,while the drought risk of winter wheat was very low in the south of Anhui Province. The drought risk of winter wheat was markedly affected by the sensitivity to drought,vulnerability and the drought resistance of winter wheat. [Conclusion] The research could provide scientific references for rational distribution of winter wheat and establishment of strategies for disaster prevention and mitigation.
文摘In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier climate in the future. Predicting the yield loss due to an anticipated drought is crucial for wheat growers. A reliable way for predicting the drought-induced yield loss is to use a plant physiology-based drought index, such as Agricultural Reference Index for Drought (ARID). Since different wheat cultivars exhibit varying levels of sensitivity to water stress, the impact of drought could be different on the cultivars belonging to different drought sensitivity groups. The objective of this study was to develop the cultivar drought sensitivity (CDS) group-specific, ARID-based models for predicting the drought-induced yield loss of winter wheat in the Llano Estacado region in the southern United States by accounting for the phenological phase-specific sensitivity to drought. For the study, the historical (1947-2021) winter wheat grain yield and daily weather data of two locations in the region (Bushland, TX and Clovis, NM) were used. The logical values of the drought sensitivity parameters of the yield models, especially for the moderately-sensitive and highly-sensitive CDS groups, indicated that the yield models reflected the phenomenon of water stress decreasing the winter wheat yields in this region satisfactorily. The reasonable values of the Nash-Sutcliffe Index (0.65 and 0.72), the Willmott Index (0.88 and 0.92), and the percentage error (23 and 22) for the moderately-sensitive and highly-sensitive CDS groups, respectively, indicated that the yield models for these groups performed reasonably well. These models could be useful for predicting the drought-induced yield losses and scheduling irrigation allocation based on the phenological phase-specific drought sensitivity as influenced by cultivar genotype.
基金Supported by the Special Fund for the Industrial Technology System Construction of Modern Agriculture in Wheat(CARS-E-2-36)the Special Fund for Henan Industrial Technology System Construction of Modern Agriculture in Wheat(S2010-10-02)National Support Program for Science and Technology(2011BAD35B03)~~
文摘[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drought resistance were selected and were classified according to their drought resistance grades determined by the Technical Specification of Identification and Evaluation for Drought Resistance in Wheat （GB/T 21127-2007）. In addition, the harvested wheat seed samples were spectrally analyzed with FOSS NIRSystems5000 near-infrared spectrum analyzer for grain quality （full spectrum analyzer） and then the forecasted regression equations were established. [Result] After the establishment of a database and validation, dis- criminated functions were obtained. The determination coefficient （RSQ） and coeffi- cients of determination for cross validation （1-VR） in the discriminant function built with seed samples from water stress area were 0.846 0 and 0.781 8, respectively, which indicated that the consistency between drought resistance and spectral charac- teristics in wheat varieties was good, and there was high correlation between the near-infrared diffuse reflectance spectra of seeds and the drought resistance in wheat. [Conclusiou] Under water stress condition, it is feasible to establish a conve- nient, rapid and no-damage identification system for the drought resistance in wheat by using the near-infrared diffuse reflectance spectrum technique to scan wheat seeds.
基金This work was supported by the National 863 Project(Grant No.2002AA224081)National Special Project for Plant Transgenic and Industry(Grant No.JY03-A-18).
文摘Under stress conditions such as droughthigh-salinity and low-temperature, the transcription factorof DREB (dehydration responsive element binding proteins)improved efficiently stress resistance by regulating the ex-pression of its downstream genes with various environmentastress resistance in plants. GmDREB gene (GenBank Acces-sion No. AF514908) encoding a stress-inducible transcriptionfactor was cloned by screening a cDNA library of Glycinemax cv. Jinong 27 with yeast one-hybrid method. GmDREBgene was 910 bp in length and encoded 174 amino acids con-taining a conserved AP2/EREBP DNA-binding domain of 58amino acids. Two conserved functional amino acids, valineand glutamic acid, were located on the 14th and the 19thamino acid residues in the conserved structural domain. Analkaline amino acid region (KKR) related to a nuclear local-ization signal was at the N-terminal, while an acidic aminoacid region (DDD) related to trans-activation was at theC-terminal. Plant expression vectors were constructed andtransformed into wheat by bombardment. In total, 13 trans-genic plants with Ubi::GmDREB and 11 transgenic plantswith rd29A::GmDREB were identified from 103 regenerationplants by molecular analysis. The drought and salt tolerancesof T1 transgenic lines with Ubi::GmDREB orrd29A::GmDREB were demonstrated to be improved ascompared to wild type. The result also suggested that bothUbiquitin and rd29A promoters could effectively drive theexpression of the GmDREB gene and enhance drought andsalt tolerance of T1 plants.
基金supported by the grants from the National Key R&D Program of China (2017YFD0100901-4 and 2016YFC0502604)the National Natural Science Foundation of China (31660390)+5 种基金the Major Special Project of Science and Technology Program in Guizhou, China (2017-5411-06 and 2017-5788)the Construction Project of State Engineering Technology Institute for Karst Desertification Control, China (2012FU125X13)the Innovation Talents Team Construction of Science and Technology in Guizhou, China (2016-5624)the Major Research Project of Innovation Group in Guizhou, China (2016-023)the Graduate Innovation Fund of Guizhou University, China (2017025)the Science and Technology Project in Guizhou, China (2019-4246)
文摘Triticum aestivum L. cv. Guizi 1(GZ1) is a drought-tolerant local purple wheat cultivar. It is not clear how purple wheat resists drought stress, but it could be related to anthocyanin biosynthesis. In this study, transcriptome data from droughttreated samples and controls were compared. Drought slightly reduced the anthocyanin, protein and starch contents of GZ1 grains and significantly reduced the grain weight. Under drought stress, 16 682 transcripts were reduced, 27 766 differentially expressed genes(DEGs) were identified, and 379 DEGs, including DREBs, were related to defense response. The defense-response genes included response to water deprivation, reactive oxygen, bacteria, fungi, etc. Most of the structural and regulatory genes in anthocyanin biosynthesis were downregulated, with only Ta DFR, Ta OMT, Ta5,3GT, and Ta MYB-4 B1 being upregulated. Ta CHS, Ta F3H, TaCHI, Ta4CL, and TaF3’H are involved in responses to UV, hormones, and stimulus. Ta CHS-2D1, Ta DFR-2D2, Ta DFR-7D, TaOMT-5A, Ta5,3 GT-1B1, Ta5,3GT-3A, and Ta5,3GT-7B1 connect anthocyanin biosynthesis with other pathways, and their interacting proteins are involved in primary metabolism, genetic regulation, growth and development, and defense responses. There is further speculation about the defense-responsive network in purple wheat. The results indicated that biotic and abiotic stress-responsive genes were stimulated to resist drought stress in purple wheat GZ1, and anthocyanin biosynthesis also participated in the drought defense response through several structural genes.
文摘Water stress treatment at different developmental stages of a winter wheat varietywas made in outdoor pot experiments from 1987 to 1988.It was found that the most sensitivestage was the booting stage and the second most sensitive stage was the flowering stage.Waterstress at most development stages affects the number of grains.Wheat water stress can be diag-nosed effectively and quickly by means of leaf temperature difference between the drought fieldand the well watered control plot measured by an infra-red thermometer.
基金supported by the National Natural Science Foundation of China (31071412)the High-Tech R&D Program of China (2012AA101105)the Key Basic Research Program of China (2009CB118300)
文摘Drought stress is one of the major factors affecting in wheat yield and grain quality. In order to investigate how drought stress might influence wheat quality during grain filling, three wheat cultivars Gaocheng 8901, Jagger and Nongda 3406 were subjected to drought stress during the grain filling stage. Neither globulin and glutenin, nor the relative percentage ofamylose significantly changed following drought treatments, whereas albumin and gliadin concentrations did. The SDS-sedimentation, which has a strong linear correlation with wheat baking quality was markedly decreased following drought stress. These results indicated that drought had an adverse effect on wheat qualit3,. In order to investigate the protein complexes in the wheat flour, the data from native PAGE and SDS-PAGE were combined and a total of 14 spots were successfully identified, and of these eight protein types were determined to be potential complex forming proteins.
基金supported by the National Natural Science Foundation of China (31171482,31571573)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China (PAPD)+1 种基金the Foundation of Excellent Doctoral Dissertation of Yangzhou UniversityChina and the Jiangsu Province College Students Innovation Training Program in 2015,China (201511117063Y)
文摘The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.
基金supported by the National Key Technology R&D Program of China (2015BAD22B01)the Plan 111 of the Ministry of Education (B12007)+1 种基金the National Natural Science Foundation of China (31500320)Special Funds of Scientific Research Programs of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau (A314021403-C5)
文摘In wheat, the ear is one of the main photosynthetic contributors to grain filling under drought stress conditions. In order to determine the relationship between stomatal characteristics and plant drought resistance, photosynthetic and stomatal characteristics and water use efficiency(WUE) were studied in two wheat cultivars: the drought-resistant cultivar ‘Changhan 58' and the drought-sensitive cultivar ‘Xinong 9871'. Plants of both cultivars were grown in pot conditions under well-watered(WW) and water-stressed(WS) conditions. In both water regimes,‘Changhan 58' showed a significantly higher ear photosynthetic rate with a lower rate of variation and a significantly higher percentage variation of transpiration compared to control plants at the heading stage under WS conditions than did ‘Xinong 9871' plants. Moreover,‘Changhan 58' showed lower stomatal density(SD) and higher stomatal area per unit organ area(A) under both water conditions. Water stress decreased SD, A, and stomatal width(SW), and increased stomatal length in flag leaves(upper and lower surfaces) and ear organs(awn, glume,lemma, and palea), with the changes more pronounced in ear organs than in flag leaves.Instantaneous WUE increased slightly, while integral WUE improved significantly in both cultivars. Integral WUE was higher in ‘Changhan 58', and increased by a greater amount, than in‘Xinong 9871'. These results suggest that drought resistance in ‘Changhan 58' is regulated by stomatal characteristics through a decrease in transpiration rate in order to improve integral WUE and photosynthetic performance, and through sustaining a higher ear photosynthetic rate, therefore enhancing overall drought-resistance.
基金the National Key R&D Program of China (2018YFD0200500) for the financial support
文摘Genetic diversity is the base of any genetic improvement breeding program aimed at stress breeding.The variability among breeding materials is of primary importance in the achievements of a good crop production.Herein,105 wheat genotypes were screened against drought stress using factorial completely randomized design at seedling stage to determine the genetic diversity and traits association conferring drought tolerance.Analysis of variances revealed that all the studied parameters differed significantly among all genotypes,indicating the significance genetic variability existed among all genotypes for studied indices.The 10 best performance genotypes G1,G6,G11,G16,G21,G26,G39,G44,G51,and G61 were screened as drought tolerant,while five lowest performance genotypes G3,G77,G91,G98,and G105 were screened as drought susceptible.Root length,chlorophyll a,chlorophyll b,and carotenoid contents were significantly correlated among themselves which exhibited the importance of these indices for rainfed areas in future wheat breeding scheme.Shoot length exhibited non-significant and negative association with other studied traits,and its selection seems not to be a promising criteria for this germplasm for drought stress.Best performance genotypes under drought stress conditions will be useful in future wheat breeding program and early selection will be effective for developing high yielding and drought tolerant wheat varieties.
文摘Drought is the most important factor limiting plant production in the majority of agricultural crops of the world. Wheat is generally grown on arid-agricultural fields. An experiment was conducted at the Plant physiology research area, Agronomic Research Institute Faisalabad, during winter 2010-11 to evaluate the effect of drought on wheat variety Lasani 2008. The experiment was comprised of following treatments. T1 Normal moisture (3 IR at CRS, Booting and grain filling), T2 No irrigation (only rainfed) control, T3 water spray (100 ppm), T4 ascorbic acid (100 ppm), T5 salicylic acid (100 ppm), T6 calcium chloride (100 ppm), T7 glycinbetain (100 ppm). According to the resulting data the treatment in which three irrigation were applied produced more no. of tillers (52%), spikelet per spike (41%), spike length (30%), grain per spike (58%), grain yield (54%), biological yield (35%) as compared to control. The treatment in which no irrigation was applied produced less no. of tillers, spikelet per spike, spike length, grain per spike, grain yield, biological yield. Thousand grain weight and harvest index were non significant among all treatments.
基金This work was supported by the State Key Basic Research and Development Plan(G1998010100)the State Natural Science Fund(30270780)the State"Tenth Five Year"Project(2001BA507A-09)of China
文摘The activities of RuBPC and C4 photosynthetic enzymes in ear and flag leaf blade were examined in wheat. The results showed that photosynthesis of ear was less sensitive to soil drought than that of flag leaf, and decrease of CO2 assimilation in flag leaf blade with water stress was more than that in ear. Compared with flag leaf, ear organs (awn, glume and lemma) had higher C4 enzyme activities and lower RuBPC activity. Under moderate water-stress, the increase of C4 enzyme activities was induced, and the increase was higher in ear than in flag leaf. Under severe water-stress, relatively higher C4 enzyme activities were still maintained in ear, rather than that in flag leaf. It suggests that high activities of C4 enzymes in ear may contribute to its high tolerance of photosynthesis to water-stress.
基金the National Research Foundation of South Africa for funding this work
文摘Recurrent drought associated with climate change is among the principal constraints to global productivity of wheat（Triticum aestivum（L.） and T. turgidum（L.））. Numerous efforts to mitigate drought through breeding resilient varieties are underway across the world. Progress is, however, hampered because drought tolerance is a complex trait that is controlled by many genes and its full expression is affected by the environment. Furthermore, wheat has a structurally intricate and large genome. Consequently, breeding for drought tolerance requires the integration of various knowledge systems and methodologies from multiple disciplines in plant sciences. This review summarizes the progress made in dry land wheat improvement, advances in knowledge, complementary methodologies, and perspectives towards breeding for drought tolerance in the crop to create a coherent overview. Phenotypic, biochemical and genomics-assisted selection methodologies are discussed as leading research components used to exploit genetic variation. Advances in phenomic and genomic technologies are highlighted as options to circumvent existing bottlenecks in phenotypic and genomic selection, and gene transfer. The prospects of further integration of these technologies with other omics technologies are also provided.
基金This study was financially supported by the China National 863 Program(2002AA2Z4011)the China National R&D Program(2004BA508B09)Texas wheat breed and physiology program.These assistances are gratefully acknowledged.We also thank Gail Petersion and Melanie Allred for their assistance when the study was going on.
文摘Field studies were conducted at Bushland, Texas, USA, in 2004 to examine usefulness of canopy temperature depression （CTD）, the difference of air-canopy temperature, in screening wheat （Triticum aestivum L.） genotypes for yield under dryland and irrigated. Forty winter wheat genotypes were grown under irrigation and dryland. CTDs were recorded after heading between 1 330 and 1 530 h on 6 clear days for dryland and 9 days for irrigation. Drought susceptible index （DSI） for each genotype was calculated using mean yield under dryland and irrigated conditions. Genotypes exhibited great differences in CTD under each environment. The dryland CTDs averaged 1.33℃ ranging from -0.67 to 2.57℃, and the average irrigation CTD were 4.59℃ ranging from 3.21 to 5.62℃. A low yield reduction was observed under dryland conditions relative to irrigated conditions for high-CTD genotypes. CTD values were highly negatively correlated with DSI under dryland, and genotypes of CTDs = 1.3℃ in dryland condition were identified as drought resistant. For 21 genotypes classified as drought resistant by DSI, their CTDs were 1.68℃ for dryland and 4.35℃ for irrigation on average; for 19 genotypes classified as drought susceptible by DSI, average CTD was 0.94℃ in dryland and 4.85℃ in irrigation. The high-yield genotypes consistently had high CTD values, and the low-yield ones had low CTD values for all measurements in dryland. After heading, genotypes maintained consistent ranking for CTD. Regression results for CTD and yield suggested that the best time for taking CTD measurement was 3-4 weeks after heading in irrigation but any time before senescence in dryland. Crop water stress index （CWSI） calculated from CTD data was highly correlated with CWSI calculated from yield, which suggesting traditional costly CWSI measurement may be improved by using portable infrared thermometers. Most importantly, grain yield was highly correlated with CTD under dryland （R^2 = 0.79-0.86） and irrigation （R^2 = 0.46-0.58） conditions. These results clearly indicated grain yield and water stress can be predicted by taking CTD values in field, which can be used by breeding programs as a potential selection criterion for grain yield and drought resistance in wheat, but a second study year is needed to confirm further.
基金supported by the National Natural Science Foundation of China (31371618)the Research Plan of Application Base of Hebei, China (17962901D)
文摘Through regulating target genes via the mechanisms of posttranscriptional cleavage or translational repression, plant miRNAs involve diverse biological processes associating with plant growth, development, and abiotic stress responses, in this study, we functionally characterized TaMIR1119, a miRNA family member of wheat （Triticum aestivum）, in regulating the drought adaptive response of plants. TaMIR1119 putatively targets six genes categorized into the functional classes of transcriptional regulation, RNA and biochemical metabolism, trafficking, and oxidative stress defense. Upon simulated drought stress, the TaMIR1119 transcripts abundance in roots was drastically altered, showing to be upregulated gradually within a 48-h drought regime andthat the drought-induced transcripts were gradually restored along with a 48-h recovery treatment. In contrast, most miRNA target genes displayed reverse expression patterns to TaMIR1119, exhibiting a downregulated expression pattern upon drought and whose reduced transcripts were re-elevated along with a normal recovery treatment. These expression analysis results indicated that TaMIR1119 responds to drought and regulates the target genes mainly through a cleavage mechanism. Under drought stress, the tobacco lines with TaMIR1119 overexpression behaved improved phenotypes,, showing increased plant biomass, photosynthetic parameters, osmolyte accumulation, and enhanced antioxidant enzyme （AE） activities relative to wild type. Three AE genes, NtFeSOD, NtCAT1;3, and NtSOD2,1, encoding superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） proteins, respectively, showed upregulated expression in TaMIR1119 overexpression lines, suggesting that they are involved in the regulation of AE activities and contribution to the improved cellular reactive oxygen species （ROS） homeostasis in drought-challenged transgenic lines. Our results indicate that TaMIR1119 plays critical roles in regulating plant drought tolerance through transcriptionally regulating the target genes that modulate osmolyte accumulation, photosynthetic function, and improve cellular ROS homeostasis of plants.
文摘Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.
文摘In order to study the effective water-saving cultivation of wheat in Sichuan under drought conditions to reduce grain loss,the effects of different irrigation methods（ natural rainfall,artificial irrigation,and infiltrating irrigation） on soil physical characteristics and main agronomic characters and yield of wheat were analyzed. The results showed that different irrigation treatments at different growth stages had different effects on soil physical characteristics and agronomic characters of wheat. At the seedling and jointing stage,there were small differences between the treatments in soil compactness,soil bulk density,and soil water content. At the flowering and maturation stage,different irrigation treatments had great impacts on soil compactness,soil bulk density,soil water content,and agronomic characters of wheat. In the hilly areas of Sichuan Basin,infiltrating irrigation at the jointing stage was the best,and wheat yield increased significantly,2 113. 46 kg/hm^2 higher than that in the control.
文摘Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.
