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This research aimed to clarify the effects of exogenously applied chitosan on the physiological characteristics, antioxidant activities, and Cd accumulation of wheat ( Triticum aestivum L.) seedlings under cadmium (Cd) stress and to identify the key indicators based on the partial least squares model. The wheat variety studied was Bainong207 (BN207), and Cd-stress was achieved by growing seedlings in a hydroponic culture experiment with 10 and 25 μmol·L -1 Cd 2+ added to the culture solution. It was found that both Cd-stress at 10 and 25 μmol·L -1 significantly inhibited the chlorophyll content, photosynthesis, and biomass accumulation of wheat seedlings. Seedling roots became shorter and thicker, and the lateral roots decreased under Cd-stress. The Cd-stress also increased H 2 O 2 and MDA accumulation and the degree of cell membrane lipid peroxidation and affected the activities of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). Under Cd stress, exogenous chitosan decreased the Cd content in the aboveground and underground parts of wheat by 13.22 %-21.63 % and 7.92 %-28.32 % and reduced Cd accumulation in the aboveground and underground parts by 5.37 %-6.71 % and 1.91 %-4.09 %, respectively. Whereas exogenous chitosan application significantly reduced the content of H 2 O 2 in roots and aboveground parts of wheat by 38.21 %-47.46 % and 45.81 %-55.73 % and MDA content by 37.65 %-48.12 % and 29.87 %-32.51 %, it increased the activities of SOD and POD in roots by 2.78 %-5.61 % and 13.81 %-18.33 %, respectively. In summary, exogenous chitosan can improve the photosynthetic characteristics and antioxidant enzyme activities of wheat seedlings under Cd stress, reduce the content and accumulation of Cd in the root and aboveground parts of wheat, and alleviate the damage of lipid peroxidation to the cell membrane. All of these results provide the basal data for the application of exogenous chitosan to alleviate Cd toxicity to wheat seedlings.

Low temperature (LT) in spring usually occurs at the booting of winter wheat, resulting in reduction of wheat yield. In this study, we used the LT-sensitive wheat cultivar 'Wanmai 52' and the LT-insensitive wheat cultivar 'Yannong 19' as experimental materials to conduct LT treatment (-2 ℃ and 0 ℃) at booting stage. After the LT treatment, we sprayed 6-benzylaminoadenine (6-BA) solutions with concentrations of 10, 20, and 30 mg·L -1 respectively, with equal mass distilled water as control to investigate the effects of spraying 6-BA on the physiological characteristics, yield and quality of wheat flag leaves after LT stress at booting stage. The results showed that compared with the control, young ear of wheat treated with exogenous spraying 6-BA was fuller, the floret morphology was improved, and the number of vascular bundles under the spike was increased. 6-BA application promoted the accumulation of soluble sugar, soluble protein, and proline in flag leaves. The activities of peroxidase and superoxide dismutase were increased, and the content of malondialdehyde was decreased. Exogenous 6-BA application decreased the number of degenerated spikes of wheat, increased the number of grains per spike and 1000-grain weight, as well as the contents of grain protein, wet gluten, and sedimentation value. In summary, exogenous 6-BA application could effectively alleviate the effects of LT stress on flag leaf and yield of wheat. Under the conditions of this experiment, the mitigation effect of spraying 6-BA solution on Yannong 19 was higher than that of Wanmai 52, and the mitigation effect of spraying 20 mg·L -1 6-BA solution on low temperature stress was the best.

Phosphogypsum is a phosphorus chemical waste which has not been managed and reused well, resultantly, causing environmental pollution and land-occupation. Phosphogypsum wastes were used as a soil amendment to assess the effect on wheat growth, yield and CO2 emissions from winter wheat fields. Its economic and environmental benefits were analyzed at the same time. The results showed that wheat yield was increased by 37.71% in the treatment of phosphogypsum of 2 100 kg x hm(-2). Compared with the control treatment, throughout the wheat growing season, CO2 emission was accumulatively reduced by 3% in the treatment of phosphogypsum waste of 1050 kg x hm(-2), while reduced by 8% , 10% , and 6% during the jointing stage, heading date and filling period of wheat, respectively; while CO2 emission was accumulatively reduced by 7% in the treatment of phosphogypsum waste of 2 100 kg x hm(-2) throughout the wheat growing season, as reduced by 11% , 4% , and 12% during the reviving wintering stage, heading date and filling period of wheat, respectively. It was better for CO2 emission reduction in the treatment of a larger amount of phosphogypsum waste. In the case of application of phosphogypsum waste residue within a certain range, the emission intensity of CO2 ( CO2 emissions of per unit of fresh weight or CO2 emissions of per unit of yield) , spike length, fresh weight and yield showed a significantly negative correlation--the longer the ear length, the greater fresh weight and yield and the lower the CO2 emissions intensity. As to the carbon trading, phosphogypsum utilization was of high economic and environmental benefits. Compared with the control, the ratio of input to output changed from 1: 8.3 to 1: 10.7, which in the same situation of investment the output could be increased by 28.92% ; phosphogypsum as a greenhouse gas reducing agent in the wheat field, it could decrease the cost and increase the environmental benefit totally about 290 yuan per unit of ton. The results demonstrated phosphogypsum wastes could obviously decrease the CO2 emission from field soil and had a great potential to control agricultural greenhouse gases. Hopefully it has an important application perspective for the low-carbon, ecological and sustainable agricultural development.

With soil culture the ecotoxicological effects of galaxolide (HHCB) and tonalide (AHTN) on the germination of wheat (Triticum aestivum) seeds were investigated. And the influence of these two synthetical musks on the wheat germination rate, inhibition rate of root elongation and inhibition rate of shoot elongation were studied. The results showed that there were no obvious dose-effect relationship between wheat germination rate and concentrations of these two synthetical musks. Lower dose (HHCB < or = 150 mg x kg(-1), AHTN < or = 200 mg x kg(-1)) could accelerate the germination of wheat. Under the test concentrations of synthetical musks, the wheat germination rates treated with HHCB and AHTN were 77.78%-95.56% and 84.44%-97.78%, respectively. There were good dose-effect relationship between inhibition rate of root elongation (or inhibition rate of shoot elongation) and synthetical musks concentrations. The EC50 of HHCB and AHTN based on shoot were 155.84 mg x kg(-1) and 290.58 mg x kg(-1), and were 215.66 mg x kg(-1) and 323.10 mg x kg(-1) based on root from linear model. The EC50 of wheat sensitive positions showed that the toxicity of HHCB was stronger than AHTN.

Seed germination, root elongation, shoot elongation and ratio of shoot to root of wheat in soils polluted by lead (Pb) and benzo (a)pyrene (B[a] P) with medium-low concentrations were studied to reveal the ecological effects of combined pollution and screen the indicative markers. Results indicated that seed germination was not sensitive to single or combined pollution of Pb or B[a] P. Root elongation was inhibited by single pollution of Pb or B[a]P to different extents. Extensive interactions between Pb and B[a]P occurred to root elongation of wheat, including synergistic-stimulatory effect and antagonistic-inhibitory effect. The joint action was mainly antagonistic. Single pollution of B [a] P had an inhibitory effect on shoot elongation. Under combined pollution conditions, the shoot elongation of wheat correlated well with Pb contents (p < 0.01). B[a] P or the interactions between pollutants had little effect on shoot elongation of wheat. The joint action on shoot elongation was consistently antagonistic. The response pattern of the ratio of shoot to root was similar to the response pattern of shoot elongation. However, the former had better correlation than the latter, indicating it as a more suitable indicative marker for Pb pollution. If lead acetate was employed instead of lead nitrate, longer root elongation, shorter shoot elongation and no effect on ratio of shoot to root were found. Therefore, the forms of Pb salt had significant influence on seed growth of wheat in soils.

Taking wheat cultivar Bainong AK58 as test material, a field experiment was conducted to study the effects of different concentration 5-aminolevulinic acid (ALA) (0,10, 30 and 50 mg x L(-1)) applied at initial heading stage on the post-anthesis dry matter accumulation and flag leaf senescence of the cultivar. Applying 10-50 mg x L(-1) of ALA benefited the dry matter accumulation, with its total amount at maturing stage being significantly higher than that of the control (0 mg x L(-1) ALA). 10-50 mg x L(-1) of ALA had no significant effects on the distribution of accumulated dry matter in leaf, stem and sheath, and grain, but increased the contribution of the dry matter to grain yield. 10-50 mg x L(-1) of ALA increased the leaf area index at milky and dough stages, but had no effects on it at flowering stage. After treated with 10-50 mg x L(-1) ALA, the leaf SPAD value and net photosynthetic rate from anthesis to milky stage were significantly higher, and the MDA content and relative electric conductivity at later grain-filling stage were lower, compared with those of the control. Applying 10-50 mg x L(-1) of ALA increased the grain number per spike, 1000-grain mass, and grain yield significantly, with the best effect when applying 30 mg x L(-1) ALA.

Through the study of allelopathy of the pericarp of Phellodendron amurense, the role of self-regeneration barriers was investigated in order to find ways and means for the protection of wild populations of P. amurense. Solution preparation: soaked pericarp of P. amurense in distilled water at 4 degrees C to get solution A, and reflux extraction of pericarp with distilled water at 100 degrees C to get solution B. Both of the solution A and solution B were used in the experiment of seed germination and seedling growth with the seeds of cabbage and wheat. The results showed that 20 g x L(-1) concentration of solution A and solution B inhibited significantly seed germination of cabbage and wheat, while 100 g x L(-1) concentration of solution A even completely inhibited the seed germination of wheat. 20 g x L(-1) concentration of solution A significantly inhibited the cabbage and wheat seedling growth, completely inhibited the root growth of cabbage, while 100 g x L(-1) concentrations of solution A completely inhibited seedling growth of cabbage and wheat. Comparing to solution A, the intensity of solution B are diminished on seed germination and seedling growth. It is concluded that the allelopathy of pericarp of P. amurense is multi-material role in the results, some of allelochemicals are easily degradable when exposed to heat. Overall, the allelopathy of pericarp of P. amurense can affect the seed germination and seedling growth. It is supposed that allelochemicals existed in the pericarp of P. amurense is one of the reason leading to difficulties in self-regeneration of its population.

The effects of water-retaining agent (60 kg x hm(-2)) and nitrogen fertilizer (0, 225, and 450 kg x hm(-2)) on the leaf photosynthetic characteristics, chlorophyll content, and water utilization of winter wheat at jointing and grain-filling stages were studied under field conditions. In all treatments, the net photosynthetic rate, stomata conductance, intercellular CO2 concentration, water use efficiency, and chlorophyll content were greater at grain-filling stage than at jointing stage. Under nitrogen fertilization but without water-retaining agent application, the water use efficiency (WUE) of single leaf at jointing stage increased with increasing nitrogen fertilization rate, while the net photosynthetic rate, stomata conductance, intercellular CO2 concentration, and transpiration rate decreased after an initial increase. The chlorophyll content was the highest under 225 kg x hm(-2) nitrogen fertilization. In the treatments of water-retaining agent application, the intercellular CO2 con- centration decreased with increasing nitrogen application rate, but the net photosynthetic rate, transpiration rate, and WUE increased. The application of water-retaining agent or its combination with nitrogen fertilization increased the chlorophyll content, but excessive nitrogen fertilization had lesser effects. At grain-filling stage, applying nitrogen fertilizer alone significantly increased the net photosynthetic rate and WUE, but decreased the stomata conductance, intercellular CO2 concentration, and transpiration rate. The chlorophyll content increased with increasing nitrogen application rate. After applying water-retaining agent and with the increase of nitrogen fertilization rate, the photosynthetic rate and WUE decreased after an initial increase, while the intercellular CO2 concentration and transpiration rate were in adverse but still lower than those without water-retaining agent application. The stomata conductance increased with increasing nitrogen fertilization rate. The chlorophyll content increased significantly under the application of water-retaining agent, but somewhat decreased under the combined application of water-retaining agent and nitrogen fertilizer. The application of both water-retaining agent and nitrogen fertilizer increased the 1000 grain mass, grain yield, and water production efficiency of winter wheat significantly, with the best effect in the treatment of water-retaining agent with 225 kg x hm(-2) nitrogen fertilization.

A field experiment was conducted at the Yuzhou Experimental Base of Henan Province to study the effects of different application rates (0, 30, 60, and 90 kg x hm(-2)) of water-retaining agent (WRA) on the root physiological characteristics, biomass, and grain yield of two winter wheat cultivars Zhengmai-9694 and Aikang-58, aimed to probe into the action mechanisms of WRA on the root system of winter wheat at its different growth stages. The application of WRA decreased the root membrane permeability and soluble sugar content, and increased the root vigor. After the application of WRA, the Zhengmai-9694 at its different growth stages had a greater decrement of root membrane permeability, compared with Aikang-58. In all treatments except 90 kg x hm(-2) of WRA, the root vigor of Aikang-58 was obviously higher than that of Zhengmai-9694. At booting and grain-filling stages, the root soluble sugar content of Zhengmai-9694 decreased much more than that of Aikang-58. In the whole growth period of the two cultivars, their root membrane permeability and soluble sugar content were the lowest in treatment 60 kg x hm(-2) of WRA, and no significant differences were observed between treatments 60 and 90 kg x hm(-2) of WRA. The root vigor of Zhengmai-9694 increased remarkably with the increasing rate of WRA application, while that of Aikang-58 was the highest in treatment 60 kg x hm(-2) of WRA. The application of WRA also increased root biomass, and at jointing and booting stages, the root biomass of Aikang-58 was much higher than that of Zhengmai-9694. However, at grain-filling stage, the biomass of Aikang-58 in treatments 60 and 90 kg x hm(-2) of WRA was lower than that of Zhengmai-9694. Treatment 60 kg x hm(-2) of WRA had the highest grain yield of the two cultivars. It was concluded that WRA had more significant effects on Zhengmai-9694 than on Aikang-58, and applying 60 kg x hm(-2) of WRA could obtain the best effect.

An investigation was made at a hilly upland in western Henan Province to understand the effects of water-retaining agent (0, 45, and 60 kg x hm(-2)), straw mulching (3000 and 6000 kg x hm(-2)), and plastic mulching (thickness < 0.005 mm) on winter wheat growth, soil moisture and nutrition conditions, and precipitation use. All the three measures promoted winter wheat growth, enhanced grain yield and precipitation use efficiency, and improved soil moisture and nutritional regimes. These positive effects were more obvious when the straw- or plastic mulching was combined with the use of water-retaining agent. Comparing with the control, all the measures increased the soil moisture content at different growth stages by 0.1%-6.5%. Plastic film mulching had the best water-retention effect before jointing stage, whereas water-retaining agent showed its best effect after jointing stage. Soil moisture content was the lowest at flowering and grain-filling stages. Land cover increased the grain yield by 2.6%-20.1%. The yield increment was the greatest (14.2%-20.1%) by the combined use of straw mulching and water-retaining agent, followed by plastic mulching combined with water-retaining agent (11.9% on average). Land cover also improved the precipitation use efficiency (0.4-3.2 kg x mm(-1) x hm(-2)) in a similar trend as the grain yield. This study showed that land cover and water-retaining agent improved soil moisture and nutrition conditions and precipitation utilization, which in turn, promoted the tillering of winter wheat, and increased the grain number per ear and the 1000-grain mass.

In 2006-2009, a Free-Air Controlled Enrichment (FACE) system was applied to study the effects of elevated ozone concentration ([O3]) on the grain protein components and their dynamics of four winter wheat varieties Yannong 19, Yangmai 16, Yangmai 15, and Yangfumai 2. Two levels of [O3] were installed, i. e., ambient level (CK-O3) and 50% higher than the ambient level (E-O3). With the increase of [O3], the grain protein content of the varieties increased, with the increment being 7.55% - 16.37% (2006 - 2007), 4.93% - 22.63% (2007 - 2008), and 2.29% - 17.65% (2008 - 2009) in the three years, respectively, and the differences between treatments, varieties, and years being all significant. Adversely, the grain protein yield was decreased significantly by 1.83% - 11.64% (2006 - 2007), - 0.41% - 24.22% (2007 - 2008), and -1.90% - 15.81% (2008 - 2009), respectively in the three years. The contents of four grain protein components (albumin, globulin, gliadin, and glutenin) were significantly higher under E-O3 than under CK-O3, and the differences between treatments, varieties, and years were significant, except the albumin and glutenin contents between treatments.

In order to provide basis for evaluating the effects of air pollutant such as O3 on crops yield and food security, the effects of O3 fumigation (ambient air, CK; 100 nL x L(-1), T1; 150 nL x L(-1), T2) on chlorophyll a fluorescence and gas exchange of a field-grown winter-wheat (Triticum aestivum L. Yang Mai 13) in different growing period were conducted via open-top chamber technique in conjunction with Diving-PAM fluorometer and LC pro + photosynthesis system. Results indicated that Fv/Fm caused by T1 was higher than 0.8, while the Pm, qP, (1-qP)/NPQ and Y(NO) were similar to those of CK, the NPQ and Y(NPQ) were increased by 13.5%-29.0% and 13.3%-22.7% respectively due to O3 stress. Under nature light (rapid light curve, RLC) and after dark adaptation (induction curve in steady-state, IC) the Yield of T1 was decreased by 4.6%-7.6% and 11.3%-19.3% respectively, with 8.0%-9.8% and 11.0%-23.1% reductions in Pn, and Gs compared to CK, respectively. In heading stage and blooming stage, the Ls of T, was greater than CK, but in filling stage and mature stage, it became lower compared to CK. The Fv/Fm was slightly lower than 0.8 under T2 treatment, with the Y(NO), (1-qP)/NPQ and c(i) were increased by 37.9%-75.6%, 157.1%-325.8% and 3.4%-18.1% relative to CK. Under RLC and IC condition, the Yield of T2 was respectively decreased by 10.2%-13.6% and 21.4%-29.1%, and the Pn, Ls, qP, Pm, NPQ and Y(NPQ) were decreased by 28.1%-39.9%, 5.2%-21.3%, 15.8%-30.4%, 27.6%-45.6%, 3.3%-52.9% and 5.7%-17.9% in comparison, respectively. Obviously the enhanced O3 causes a significant decrease in the capacity of photosynthesis of winter wheat, and the influence mechanism presents a series of dynamic changes according to growing seasons. The reduction of Fv/Fm under T1 treatment is a response of PS II reaction center to the increase of NPQ, and the decrease in Pn and Yield is a consequence of protective adjustment, by this approach, the antioxidant system and energy dissipation mechanism can thus prevent light damage to the PS II reaction center of winter wheat. Under T2 treatment, the CO2 assimilation and Q(A) re-oxidizing during actinic illumination are restricted, the energy dissipation mechanism was destroyed, and the reduction of photosynthesis was mainly due to damage in photosystem caused by O3 and excess light. The critical loads for O3 of PS II reaction center is between 100 nL x L(-1) and 150 nL x L(-1) close to 100 nL x L(-1). While the Fv/Fm value is not an effective index for assessing O3 influence on winter-wheat. Although the winter-wheat can have certain adapted ability to O3 stress, the growing enhancement of surface O3 is still a great threat to agricultural production in China.

A FACE (Free-air component enrichment) system in a rice/wheat rotation field was used to investigate the effects of arbuscular mycorrhizal fungal (AMF) inoculation on wheat growth and soil microbial biomass under elevated tropospheric O3 concentration. The elevated O3 concentration tended to increase AM colonization of wheat seedling and bate plant growth during the booting period, then significantly (p < 0.05) reduced aerial biomass, individual yield and kernel weight by 22%, 29% and 9%, respectively, and decreased soil microbial biomass N by 37% after wheat harvesting. However, the total N content in wheat grain significantly (p < 0.05) increased from 2.2% to 2.6%. Under elevated O3 concentration, AMF inoculation accelerated AM colonization successfully, and improved colonization rate and aerial biomass significantly (p < 0.05) during the booting period, thus reduced the damage of aerial biomass by 50% when harvesting, and increased soil microbial biomass N significantly (p < 0.05) related to the noninoculated treatment. Although wheat yield didn't increase, the total N content in grain decreased to the same level of that of the control wheat. It suggested that higher AM colonization is the resistance behavior of wheat in response to O3 intimidation, and AMF inoculation can accelerate wheat growth, increase root exudates and soil microbial biomass subsequencely.

The ecotoxicological effects of oxytetracycline (OTC) on the germination of wheat (Triticum aestivum) seeds and the early development of wheat seedlings were investigated. The results showed that the elongation of wheat shoots and roots was significantly (p < 0.05) inhibited by OTC, and there was a good dose-response relationship between the OTC concentration and inhibition rates. According to the linear regression equation, EC50 of OTC for inhibiting wheat shoot and root elongation was 65.5 mg/L and 34.7 mg/L, respectively. However, the germination of wheat seeds was not inhibited by OTC. Moreover, after a 21-day exposure to 0.15-2.40 mg/L OTC, the content of chlorophyll (CHL) decreased by 35.6%-47.3%, and the content of soluble protein (SP) in the leaves and roots of wheat plants decreased significantly. After a 7-day exposure, the activity of SOD and POD in wheat was not changed significantly. With the prolongation of exposure time, the activity of SOD and POD in wheat leaves and roots decreased significantly, the inhibition rate of SOD activity in roots increased up to 72.3% after a 21-day exposure to 2.4 mg/L OTC, which indicated that the antioxidant defense systems were damaged. The results above suggested that the low concentration OTC had ecotoxicological effects on wheat seedlings after chronic exposure.

With the fluorescent compound conjugates substrates, soil xylanase and cellulose in a free-air carbon dioxide enrichment (FACE) experiment were measured on the base of 96 microplate and fluorescence detection, aiming at testing its feasibility in sacchariase activity measurement. The results show that sacchariase activity can be tested and the data exhibit better repeatability(coefficient of variability <= 4.879%). Compared with spectrophotometric assay, this method allows a large number of soil samples and/or enzymes to be analyzed in a short time accurately and conveniently. Soil xylanase activity tends to be greater at elevated CO2 which significantly increases in jointing, heading and ripening stages of wheat and in heading and ripening stages of rice (P < 0.05), and the crop metabolizes rapidly under FACE condition and soil microorganisms are affected, which causes elevation of xylanase acitivy. Compared with ambient CO2, soil cellulose activity decreased slightly under elevated CO2 but there was no significant difference between treatments, indicating the cellulose activity was not influenced intensively in a short time.

Pollens of Trititrigia substitution line SN0095 were radiated with 60Co-gamma ray and cytological characters of the progenies M1 and M2 were studied. The results showed that variations with different frequencies and chromosome numbers (2n=41, 2n=40 and 2n=39) were observed in both M1 and M2. Abnormal phenomena, such as univalents, multivalents, chromosome fragments, laggard chromosomes, chromosome bridges and micronucleus, appeared in high frequencies during the meiosis. It suggested that irradiation could promote changes of chromosome number and configuration efficiently, and could lead to rearrangements or translocations between chromosomes. The M2 progenies were examined using BARC159(240), a Thinopyrum intermedium-specific SSR marker of SN0095. Most M2 plants carried the locus BARC159(240), which indicated that the specific segment involving the locus BARC159(240) of Thinopyrum intermedium existed in these plants. However, a band of common wheat YN15 disappeared in a few plants although the locus BARC159(240) existed, which implied that chromosome rearrangements may have occurred in these plants.

In this study, peaT1 gene was subcloned into the Pichia pastoris expression vector pPIC9K, which contained both the methanol-inducible promoter and the transcription terminator of the AOX1 gene, resulting the plasmid pPIC9K-peaT1. The recombinant plasmid was linearized by Sal I or Bgl II and transformed into P. pastoris GS115 by electroporation method. Recombinant strain was screened by Minimal Dextrose Medium and further confirmed by PCR. The gene was in frame integrated into the Pichia genome through homologous recombination, resulting the recombinant strain. Regulated by the alpha-Factor, promoter of AOX1 gene and termination signal of yeast genomic, the recombinant protein was expressed and secreted into the supernatant. The SDS-PAGE analysis indicated that the apparent molecular weight of target protein was about 35 kD. Bioassay results showed that the inhibition rate of the expressed protein against TMV was 30.37%. The supernatant was collected and then purified by anion exchange chromatography. This protein can promote seedling growth of wheat obviously.

O3-FACE (ozone-free air controlled enrichment) platform has been established for observing the photosynthetic damage induced by elevated O3 in functional leaves of two winter wheat (Tritcium aestivum L.) varieties (Yangmai 16 and Yannong 19) during grain filling stage. The results showed that the response trend of all the parameters was similar: (1) The net photosynthetic rate (Pn) decreased gradually and after 35 days of O3 treatment, Pn decreased by 56.21% and 21.82% for Yannong 19 and Yangmai 16, respectively. (2) Chlorophyll fluorescence kinetics parameters changed as decreased in Fv/Fm (maximal photochemical efficiency of PS II in the dark), qp (photochemical quenching), Phiexe (excitation capture efficiency of PS II or intrinsic PS II efficiency), PhiPSII (actual photochemical efficiency of PS II in the light), and increased in NPQ (non-photochemical quenching); Energy distribution parameters changed as rose in % D (fraction of light absorbed in PS II that is dissipated in the PS II antenna), reduced in % P (fraction of light absorbed that is used in photochemistry), and no significant changed in % X (fraction of light absorbed that is not used or dissipated in the PS II antenna). After 35 days of O3 treatment, the actual photochemical efficiency of PS II of Yannong 19 and Yangmai 16 were reduced by 24.42% and 9.97%, respectively.(3) It was declined in Chlt/Car (total chlorophyll content/carotinoid content) while the ratio of Chla/Chlb (chlorophyll a content/chlorophyll b content) was increased. There was a growth in Mg2+, Ca2+-ATPase, activities and ATP contents in chloroplast. The extent of variation in the above parameters and the differences between the two varieties were enlarged as the O3 treatment time increasing and it could be found a more serious damage effect in Yannong 19 than that of in Yangmai 16. In conclusion, the responses of the capacities of defense and repair systems of the two varieties to elevated O3 were reflected by increase in heat dissipation, changes in contents and composition of photosynthetic pigments, and enhancement in the ATP (ATP enzyme) activities in chloroplast. With the time of O3 treatment elongating, there was an accumulation effect of 03 damage to wheat and a great different tolerance between the two varieties was observed.

Glycosyltransferases (GTs) play important roles in stress responses of plants by glycosylating hormones and secondary metabolites. UDP-glucosyltransferases (UGTs), which use UDP-glucuronic acid in animals, UDP-glucose, UDP-galactose, and UDP- rhamnose in plant as sugar donors, belong to family 1 of GTs. As a secondary metabolite produced by Fusarium graminearum during infection of grains, deoxynivalenol (DON) is not only harmful to human and animal's health by inhibiting protein synthesis, but also acts as a virulence factor during fungal pathogenesis. In order to study expression profile of UGT genes in wheat, two UGTs, designated TaUGT1 and TaUGT2, were isolated from bread wheat (Triticum aestivum L.) by reverse transcriptase-polymerase chain reaction. The genomic sequences of both genes had one intron. Their coding sequences shared 91% and 90% similarities at nucleic acid level and the deduced protein sequence level. The analysis of conserved domain revealed that these two cDNAs encoded UDP-glucoronosyl and UDP-glucosyl transferase with PSPG (Putative secondary plant glycosyltransferase) domain. Real-time PCR was carried out to detect the expression profiles of the two UGTs in wheat under various stress conditions. In young spikes infected by Fusarium graminearum, TaUGT2 was induced but TaUGT1 was repressed. These two genes were upregulated under higher NaCl concentration. In conclusion, TaUGT2 may participate in wheat resistance to Fusarium head blight in which mycotoxin DON plays a role, and these two genes might be involved in responses of wheat to salt stress.

H2O2 burst in the defense responses of Wheat (Triticum aestivum L.) infected with compatible and incompatible leaf rust fungus races (Puccinia recondita f.sp. tritici) was investigated firstly. Cytofluorimetric analysis using the fluorescent probe DCFHDA scrutinized the generation of H2O2 in wheat primary leaves. The results indicated that H2O2 burst could be induced by either compatible or incompatible leaf rust fungus. However, the kinetics of H2O2 burst in incompatible interaction were biphasic, and the peak of phase II (20h after inoculation) was much higher than that of phase I (12h after inoculation), whereas, there only existed the weak and transient phase I H2O2 accumulation at 12h after inoculation in compatible interactions. In addition, pharmacological experiments were carried out. Antioxidants (AsA, DTT) and inhibitors of the mammalian neutrophil NADPH oxidase (DPI, imidazole) were separately injected into wheat primary leaves before inoculation to study their effects on hypersensitive reaction (HR) and H2O2 production in incompatible interaction. It was observed that treatments of wheat leaves with AsA, DTT, DPI or imidazole obviously suppressed the two peaks of intracellular H2O2 burst, whereas the second peak was inhibited much more. Moreover, the area of hypersensitively dead cells was decreased in the four treatments. These results suggested that NADPH oxidase may play an important role in H2O2 generation during wheat-leaf rust fungus interaction, and H2O2 burst may be involved in HR caused by leaf rust invading.

Through the determinations of wheat (Triticum aestivum) seed germination and seedling growth, the toxic effect of emerging pollutant musk ketone was investigated. The results showed that 10 mg x kg(-1) of musk ketone could significantly inhibit the seed germination rate (P < 0. 05) and the seedling's root- and shoot elongation of wheat (P <0.01), and there existed a significant (P < 0.01) dose-effect relationship between musk ketone and root- and shoot elongation, suggesting that the seedling's root- and shoot elongation of wheat could indicate the pollution extent of musk ketone in soil. The correlation analysis revealed that under soil musk ketone pollution, there was a significant (P < 0.01) positive correlation between root- and shoot elongation, and a significant (P < 0.01) negative correlation between seed germination and biomass. Besides the solubility in water, the toxicity of organic pollutant was related to its chemical characters, and its action mechanisms to the target organism.

With open-top chamber (OTC), the effects of elevated CO2 (550 micromol x mol(-1)) and O3 (80 nmol x mol(-1)) and their combination on the biomass, total phenols, and flavone at different growth stages of spring wheat, as well as the yield components at maturity stage, were studied. The results showed that under elevated CO2, the biomass and yield components were significantly higher than those under ambient CO2 (342 micromol x mol(-1)), while under elevated O3, these parameters were significantly lower than those under ambient O3 (30 nmol x mol(-1)). The combination of elevated CO2 and O3 was at the intermediate place, indicating that CO2 could mitigate the negative effects of O3, while O3 could weaken the positive effects of CO2. Elevated CO2 and O3 increased the content of total phenols in wheat leaves, and the combination of elevated CO2 and O3 had the greatest effect. However, at late growth stage, the increment of total phenols was decreased. At early growth stage, the total content of leaf flavone under elevated CO2 and O3 and their combination was lower than the control, but at maturing stage, it was in adverse.

Different intensities of salt- or alkali stress were established by mixing different concentrations of NaCl and Na2SO4 or NaHCO3 and Na2CO3, respectively, and wheat-wheatgrass (Triticum aestivum L. -Agropyron intermedium) seedlings were grown under the stresses for 12 days. The pH value and the Na(+), K(+), free Ca(2+), Cl(-), SO4(2-), NO3(-), H2PO4(-), and organic acid concentrations in the fresh shoots of stressed wheat-wheatgrass seedlings were determined, aimed to approach the characteristics of pH and ion balance in wheat-wheatgrass under salt- or alkali stress. The results showed that intracellular pH was relatively stable under both stresses. Cl(-) concentration increased sharply and organic acid concentration changed less under increasing intensity of salt stress, while it was, in adverse under increasing intensity of alkali stress. Under both stresses, the cations in the fresh shoots were mainly Na(+) and K(+), but the anions were different. Under salt stress, inorganic anions were the dominant components and contributed 61.3 %-66.7% to the total negative charge, while under alkali stress, the contribution of organic acid to total negative charge increased from 38.35% to 61.6% with increasing stress intensity, and became the dominant component. It was concluded that organic acid accumulation might be a key physiological response of wheat-wheatgrass for its keeping pH and ion balance under alkali stress.

With wheat cultivars Yumai 34 (strong-gluten wheat) and Yumai 50 (weak-gluten wheat) as test materials, a field experiment was conducted to study the effects of three irrigation treatments (irrigation at jointing stage, at jointing and grain-filling stages, and at jointing, grain-filling, and pre-maturing stages), three nitrogen application rates (0, 150, and 270 kg x hm(-2)), and their combinations on the contents and components of protein and starch in wheat grains. The results showed that for strong-gluten wheat cultivar Yumai 34, applying 270 kg x hm(-2) of N increased the total content of protein and the contents of albumin, gliadin and glutelin, and enhanced the glutelin/gliadin ratio. This application rate of nitrogen also increased the total content of starch and the content of amylopectin, and decreased the amylose/amylopetin ratio. For weak-gluten wheat cultivar Yumai 50, applying 150 kg x hm(-2) of N increased the contents of albumin and gliadin, and decreased the contents of globulin and glutelin and the glutelin/gliadin ratio. The amylopectin and starch contents also increased when the N application rate was 150 kg x hm(-2). Non-N fertilization or applying 270 kg x hm(-2) of N decreased the accumulation of protein and starch, and resulted in a decrease of grain yield. Among the irrigation treatments, irrigation at jointing and grain-filling stages promoted the accumulation of protein and starch in grains and increased the grain yield, while the other two treatments were unbeneficial to the accumulation of protein and starch and decreased the grain yield. Applying 270 kg x hm(-2) and 150 kg x hm(-2) of N combined with irrigation at jointing and grain-filling stages was the ideal management regime for the high yield and good quality of strong- and weak-gluten wheat cultivars, respectively.

This paper studied the effects of nitrogen application rate on the soil enzyme activities in the rhizosphere of wheat cultivars Lankaoaizao 8, a large spike genotype, and Yumai 49-198, a small spike genotype, under high yield condition. The results showed that the enzyme activities in rhizosphere soil had similar changing trends with wheat growth. The protease, urease and dehydrogenase activities in rhizosphere soil increased with wheat growth, maximized at heading stage, jointing stage, and heading stage, respectively, and decreased thereafter. Catalase activity increased with wheat growth, and peaked at maturing stage. At the same growth stage, the protease, catalase and dehydrogenase activities in rhizosphere soil of the two cultivars increased with increasing nitrogen application rate and peaked at 180 kg N x hm(-2). Urease activity also increased with increasing nitrogen application rate, and the maximum activity was observed at 360 kg N x hm(-2).

A soil column experiment was conducted with a fertile Eum-Orthic Anthrosols to study the effects of spatial coupling of watering and nitrogen (N)- and phosphorus (P) fertilization on the photosynthetic characteristics and grain yield of winter wheat. The column consisted of three layers, each layer being 30 cm in thickness and with an underlying 2 cm layer of coarse sand to obstruct water- and nutrient exchange. The results showed that relative content of chlorophyll (SPAD), net photosynthetic rate (P(n)), and grain yield were significantly lower in the treatment of 0-30 cm soil drought and 30-90 cm soil wetness (D) than in that of 0-90 cm soil wetness (W). In these two watering treatments, a combined application of N and P got the highest SPAD, P(n) and grain yield, followed by applying P, and N. The SPAD, P(n) and grain yield were significantly higher when the fertilizer N was applied in 0-90 cm layer than in 0-30, 30-60 and 60-90 cm layers, respectively. No significant differences in SPAD, P(n) and grain yield were observed when fertilizer P was applied in 0-90 cm layer and in 0-30 cm layer. In treatment W, the SPAD, P(n) and grain yield were the highest when N and P were applied in 0-90 cm layer, had no significant differences with those when the N and P were applied in 0-30 cm layer, but were significantly higher than those when the fertilization was carried out in 30-60 and 60-90 cm layers. In treatment D, no significant difference in SPAD was observed when the N and P were applied in different layers, but P(n) and grain yield were significant higher when the N and P were applied in 0-90 cm than in 30-60 cm layer, and in 30-60 cm than in 60-90 cm layer. It was concluded that whether in treatment W or in treatment D, a combined application of N and P should be carried out in 0-30 cm soil layer.

Objective: To investigate the activity and the location of the endogenesis inhibitory substances in seed of of Thesium chinense., Method: The rough extracts from different concentrations, places and extracting times of T. chinense seeds were prepared and determined by its effect on wheat and Brassica sp seed., Result and Conclusion: The extract dramatically inhibited the germentation and the growth of wheat and Brassica sp seed and the inhibitory activity was positively related to the concentration of the extracts. When the concentration reached 0. 32 g mL(-1), wheat seed did not germentate. With increasing the extracting times, the inhibitory activity first decreased, then increased. The capsule and kernel both had inhibitory substances and the latter was stronger than the former. Highly active inhibitory substances were found first time in the seed of T. chinense.

A positive clone was screened from Alternaria tenuissima expression library. The result of sequencing and gene analysis indicated that the cloned DNA fragment has a complete ORF, which was named peaT2 (Protein Elicitor from Alternaria tenuissima 2) with the GenBank accession number EF212880. The gene was amplified by PCR and subcloned into the pPIC9K of Pichia pastoris expression system. The resulting recombinant plasmid pPIC9K/peaT2 was verified by sequencing and digested by Sac I. The linearized DNA was transformed into P. pastoris GS115 by electroporation. By means of MD and G418-YPD plates and PCR, the recombinant P. pastoris strains (his- mut+) were obtained. A recombinant clone cultivated on YPD plate with high concentration of G418 was randomly selected as expression strain. The protein expression was induced by methanol and analyzed by 12% SDS-PAGE. The results of SDS-PAGE and Western blot indicated that this gene was expressed successfully in P. pastoris with the induction of methanol. In BMMY culture medium, the expressed protein reached its maximum amount at 72h, whereas no corresponding protein was detected in the negative control. Bioassay was performed with the expressed protein. After soaking with the expressed protein for 8h, wheat seeds were cultured, the height of seedlings was measured after 24h, 36h, 48h, 7d, respectively, and the root length was measured after 7 days. The results showed that the expressed protein can promote seeding growth and root length obviously in appropriate concentration. It is revealed that PeaT2 can act as protein elicitor.

In this paper, the effects of different nitrogen application rates on the nitrate reductase (NR) activity, nitric oxide (NO) content and gas exchange parameters in winter wheat (Triticum aestivum L.) leaves from tillering stage to heading stage and on grain yield were studied. The results showed that the photosynthetic rate (P(n)), transpiration rate (T(r)) and instantaneous water use efficiency (IWUE) of leaves as well as the grain yield were increased with increasing nitrogen application rate first but decreased then, with the values of all these parameters reached the highest in treatment N180. The NR activity increased with increasing nitrogen application rate, and there was a significant linear correlation between NR activity and NO content at tillering and jointing stages (R2 > or = 0.68, n = 15). NO content had a quadratic positive correlation with stomatal conductance (G(s)) (R2 > or = 0.43, n = 15). The lower NO content produced by lower NR activity under lower nitrogen application rate promoted the stoma opened, while the higher NO content produced by higher NR activity under higher nitrogen application rate induced the stoma closed. Although the leaf NO content had a quadratic positive correlation with stomatal conductance (R2 > or = 0.36, n = 15), no remarkable correlation was observed between NR activity and NO content at heading stage, suggesting that nitrogen fertilization could not affect leaf NO content through promoting NR activity, and further more, regulate the stomatal action. Under appropriate nitrogen application the leaf NR activity and NO content were lower, G(s), T(r) and IWUE were higher, and thus, the crop had a better drought-resistant ability, higher P(n), and higher grain yield.

By means of indoor pot experiment, three phytohormones, gibberellic acid (GA3), zeatin and zeatin riboside (Z&ZR), abscisic acid (ABA) of wheat ( Triticum acstivnm) were measured under the stress of fluoranthene and benzo(a)pyrene in meadow brown soil singlely and combinedly. The results indicated that significant dose-response relationship was observed between ABA contents and the concentrations of single fluoranthene and combined pollution of fluoranthene and benzo(a)pyrene, and ABA content responded more intensive to single fluoranthene than to combined treatment. When treated with 16 mg x kg(-1) single fluoranthene, ABA content increased by 198% as compared with control. Significant effects on GA3 content of combined treatment were also observed, but GA3 responded insensitively to single fluoranthene and benzo(a)pyrene treatment. Z&ZR responded intensively under stress of both single and combined pollution, and the inducible effects were accordant. It can be concluded that endogenous phytohormones play an important role in indicating PAHs polluted soil, and the sensitivity of the three phytohormones responded to fluoranthene and benzo(a)pyrene single and combined pollution is in the sequence: Z&ZR > ABA > GA3.

Anthocyanin synthesis regulation gene C1-Lc was used as the reporter gene to optimize the parameters of gene-gun transformation protocol through counting of red spots on wheat calli after transient expression. Wheat Beclin1 like gene TaTBL and thiosulfate sulfutransferase gene TaTST proved to have an increased expression level after induction of wheat powdery mildew fungus (Erysiphe graminis f.sp. tritici Em. Marchal.). These two resistance-related genes were constructed into expression vectors driven by the strong ubi promoter and used to perform genetic transformation on wheat cv Yangmai158 immature embryo-derived calli through particle bombardment. After two rounds of herbicide bialaphos selection and regeneration, herbicide-resistance plants were obtained, which were subsequently subjected to PCR analysis. Five TaTBL transgenic plants and six TaTST transgenic plants were identified. Pathogen inoculation of detached leaves showed that the introduction of exogenous gene increased wheat resistance level by delaying the development of powdery mildew symptoms.

Petroleum-contaminated soil after five-year phytoremediation was taken as tested soil initially spiked with a serial diesel concentration of 5 000, 15 000 and 30 000 mg/kg (dry weight). Residual concentrations of mineral oil by chemical analysis of gravimetry, as well as the soil-based eco-toxicity to wheat (Triticum aestivum L.), the terrestrial higher plant by several ecotoxicological bioassays including seed germination and root elongation test, early seedling growth test, contents of cytochrome P450 monooxygenases, activities of antioxidant enzymes (superoxide dismutase, SOD, and peroxidase, POD), and lipid peroxide (malondialdehyde, MDA content in wheat seedling leaves, etc. were evaluated. Results showed that mineral oil was well removed in each treatment by chemical analysis, with residual concentrations ranging from 199 to 877 mg/kg (dry weight) and with total removal rates between 90.1% and 97.2%. The evaluating results by eco-toxicological assays differed to some extent from those by chemical analysis, meanwhile, eco-toxicity of each treatment differed depending on endpoints by different bioassays. Among the ecotoxicological indexes, root length (48 h), root fresh weight (7 d), contents of P450, activities of SOD, and contents of MDA, etc. exhibited better indication to the soil toxicity. The general evaluation by combining the two analyses chemical and eco-toxicological indicated that the ecological risk was higher in most intermediately- and heavily-contaminated treatments (initially spiked with diesel concentration of 15,000 mg/kg and 30,000 mg/kg).

The effect of Cu pollution on the Cu uptake by wheat, the characteristics of chlorophyll concentration, and the visible-near infrared spectra were studied under the condition of solution culture, and the relationships among the three indices were discussed. The results indicate that the content of Cu in TritiZnm aestivum L. increases and the concentration of chlorophyll reduces with the increase of Cu in solution. The spectral characteristics also take on the disciplinary diversification (the spectral reflectivity ascended in the visible light band and decreased in the near infrared band; the range of red edge shift decreased) with the increase of Cu in solution.

This paper studied the effects of short- and long term abscisic acid (ABA) treatments on the CO2 assimilation (Pn), carboxylation efficiency (CE), response of Pn to CO2, and antioxidant enzyme activities of wheat seedlings exposed to UV-C. The results showed that under no UV-C, short- and long term ABA treatments increased Pn by 14.69% and 20.46%, and decreased stomatal conductance (Gs) by 14.74% and 17.31%, respectively, compared to the control, while no effects were observed on intercellular CO2 concentration (Ci) and CE. Under UV-C, the Pn, CE, Gs and Ci decreased, with the least decrease in long term ABA treatment, less in short term ABA treatment, and the most in control. ABA could increase the response of Pn to CO2, while UV-C inhibited it. In ABA treatments, antioxidant enzyme activities were enhanced, while MDA content was decreased. Under UV-C, CAT activity increased first, reached its maximum after 1 h, and decreased then. The activities of SOD and POD in ABA treatments increased first and decreased then, with the greater increase in long term ABA treatment than in short term ABA treatment, while those in the control decreased. It was suggested that through enhancing Pn and antioxidant enzyme activities, ABA could enhance the resistance of wheat to UV-C, and long term ABA treatment had better effects than short term ABA treatment.

The changes in cyanide-resistant respiration and metabolism of active oxygen species in drought-sensitive and drought-resistant wheat seedlings under water stress were studied. In general, drought stress decreased the level of cyanide-resistant respiration and AOX1 mRNA content in wheat seedling leaves. But the drought-resistant cultivars, which had much higher level of cyanide-resistant respiration and AOX1 mRNA content than the drought-sensitive ones, presented an ability to adapt to mild drought stress. Under drought stress, the drought-sensitive wheat seedling leaves had higher O(-.)(2) and H(2)O(2) contents, but lower SOD, POX and CAT activities than drought-resistant cultivars. We guessed that severe drought stress could break down the balance between active oxygen species and cyanide-resistant respiration. However, cyanide-resistant respiration still could participate in the drought-resistance by lowering the level of active oxygen species besides by other mechanism.

Sodium nitroprusside (SNP) could ameliorate the inhibition effect of Al on root growth of rye (Secale cereale L. cv. King) and wheat (Triticum aestivum L. cv. Jinmai47). Respiratory rate, P/O, OPR (oxygenated phosphate rate), R(3) (oxygen consumption rate with ADP and substrate present), R(4) (oxygen consumption rate with substrate) and RCR (respiratory control ratio, R(3)/R(4)) of root tips from rye and wheat decreased, as well as the activities of H(+)-ATPase, H(+)-PPase, Na(+)-K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase, but they increased with SNP treatment. It showed that mitochondrial respiratory functions of root tips from rye and wheat were damaged, phosphorylation was un-coupled by Al, but that of rye was less than that of wheat. Rye has high Al-resistance ability than wheat. SNP is one of donor of NO, it is suggested that NO can ameliorate remarkably respiratory dysfunction resulted from Al stress, so that NO can ameliorate the inhibition effect of Al on plant growth.

In this paper, a solution culture experiment was conducted to study the effects of environmental factors on Cd biotoxicity and phytochelatins (PCs) production in wheat. The results showed that Cd stress had significant inhibitory effects on wheat growth and PCs overproduction. The Cd biotoxicity and Cd uptake by wheat were affected in varying degrees by soil pH, Ca and S, and the levels of PCs production in root were consistent with the changes of Cd biotoxicity. Furthermore, the Cd biotoxicity was decreased with increasing P supply, coinciding with the decrease of PCs level in root. Mg had no obvious effect on both Cd biotoxicity and PCs level in root. The present results further confirmed that the induced PCs production level by Cd was related to Cd biotoxicity in plant, suggesting that PCs could be a promising biomarker for estimating Cd phytotoxicity.

By adding different concentration SO2 to culture boxes, this paper studied the responses of wheat seedling's superoxide anion radical O2*- and antioxidant enzymes to SO2. The results showed that when the concentration of SO2 was 10 and 40 microl x L(-1), the O2*- content and peroxidase (POD) and catalase(CAT) activities of wheat leaf were increased, while the activity of superoxide dismutase(SOD) was reduced. When the SO2 concentration was 50 microl x L(-1), the activities of POD and CAT were decreased, with the top end leaves appeared necrosis, and more fungi multiplied on green leaves. Presoaking wheat seeds with 1 mmol x L(-1) salicylic acid (SA) for 6 h or with 10 mmol x L(-1) H2O2 for 12 h could efficiently alleviate the oxidative stress caused by SO2, with the O2*- content decreased and the activities of test antioxidant enzymes increased. Under SO2 fumigation, ethylene significantly inhibited the activities of test enzymes, and promoted the O2*- production rate. When applying SA and ethylene at the same time, SA could almost completely eliminate the influences of ethylene on O2*- production and test enzyme activities.

Results in this paper showed that the effect of nitric oxide (NO) donor, sodium nitroprusside (SNP), which could promote the germination of wheat seeds under osmotic stress, was through enhancing imbibition using water content determination and imbibition analysis of wheat seed. SNP could also enhance amylase isozyme I activities, accelerate the liquefaction of endosperms, while have no effect on esterase. Moreover, SNP could strongly increase the sugars, such as the fructose, glucose and sucrose contents in wheat seeds during early germination (12 h) under normal conditions. When the seeds were treated with SNP with or without PTIO, an NO scavenger, and different exogenous sugars, i.e. fructose, glucose and sucrose, it was found that these sugars might activate amylase isozyme I activity mediated by the signal molecule NO to start the early stage of germination.

Two wheat cultivars (Triticum aestivum L.), HF9703 tolerant to drought and SN215953 sensitive to drought, were used to study the effects of glycinebetaine on the composition and function of thylakoid membrane. The wheat seedlings with two leaves were pretreated with Hoagland solution containing 1.5 mmol/L glycinebetaine (GB) for 72 h, then cultured with Hoagland solution containing 15% PEG-6000 for 48 h. The seedling leaves were used for mensuration. The results indicated that the chlorophyll, monogalactosyl diaylglycerol (MGDG), digalactosyl diacylglycerol (DGDG) and phosphatidylglycerol (PG) contents of the two wheat cultivars decreased significantly (P<0.05) under drought stress. GB alleviated their decrease. The sulfoquinovosyl diacylglycerol (SQDG) content, trans-hexadecenoic [16:1(3t)] and saturated fatty acid content of MGDG in HF9703 increased significantly (P<0.05), while in SN215953, the sulfoquinovosyl diacylglycerol (SQDG) and trans-hexadecenoic [16:1(3t)] contents decreased significantly under drought stress, but the saturated fatty acid content of MGDG increased slightly. These differences between the two wheat cultivars might account for much of the difference in drought tolerance between them. Ca2+-ATPase activity of thylakoid membrane, Hill-reaction activity and photosynthesis were decreased markedly (P<0.05) by drought stress. GB ameliorated these effects on thylakoid membrane, and the effect of GB on SN215953 was stronger than on HF9703. Discussion was made on the possible mechanism of the alleviating effect of root-applied GB on the composition and function of thylakoid membrane.

Glycine betaine (GB) and proline contents of leaf and root were simultaneously determined by HPLC-ESI-MS at seedling stage in the three wheat (Triticum aestivum L.) varieties (salt tolerance from high to low), SW12, Ningchun No.4 and Chinese Spring (C.S) under 5 different salt stress levels. The GB contents among SW12, Ningchun No.4 and C.S were found outstanding difference by ANOVA (P<0.01) and consistent with salt tolerance in wheat. Proline contents were not different among 3 wheat varieties in leaf, but difference was found in the root between the Ningchun No.4 and C.S (P<0.05). The result suggested GB, as one of the materials for osmotic adjustment in plant, had the closest relationship with salt tolerance and could be used as an index of salt tolerance in wheat.

Wheat (Triticum aestivum L.) seedlings were grown in taurine solution at concentrations of 10, 100, 500, 1000 and 5000 mg/L, and the photochemistry efficiency, the relative permeability of membrane, membrane lipid peroxidation and the growth indexes in wheat seedlings were determined. The results showed that taurine treatments distinctly promoted the growth of wheat seedlings and increased root length, plant height, dry weight and fresh weight single plant of wheat seedlings. In addition, the photochemistry efficiency in the leaf was also increase, and the membrane relative permeability and the content of membrane lipid peroxidation product MDA were decreased, with an optimum treatment concentration at about 500 mg/L. It suggests that taurine has protective effects on the cell membrane of wheat seedlings to the certain extent.

Field experiments were conducted in 1998-2000 to investigate the effects of EAN applied at different growth stages (basal, tillering, jointing, booting and whole growth stage) on wheat growth and nitrogen utilization. Compared with single NO3-, EAN as basal fertilizer, tillering dressing and jointing dressing promoted dry matter and nitrogen accumulation after heading, LAI at booting stage, and chlorophyll content of wheat. Grain yield was also increased significantly. Nevertheless, there was no obvious promoting effect of EAN at booting dressing. No significant response of plant growth under EAN was observed over whole growth stage, compared with EAN at early stages, indicating that EAN after jointing was not effective to increase nitrogen utilization and wheat growth. But, it was more effective on decreasing N leaching than other EAN treatments. All EAN treatments increased nitrogen flow efficiency (NFE) and nitrogen recovery efficiency (NRE), compared with single NO-, but EAN treatments before jointing had significant effects on increasing nitrogen utilization. Besides these, EAN a sjointing dressing improved the leaf photosynthetic characteristics during the late developmental stage and the remobilization of dry matter to grain, while EAN a s basal fertilizer an d tillering dressing was more related to increased tillering.

Biological and physico-chemistry experiments were conducted to study the effects of dissolved organic matter (DOM) on eco-toxicity of phenanthrene in a soil. The results showed that DOM was a kind of surfactant. The sensitive range of phe inhibiting wheat root elongation was from 0 to 200 mg/kg, and median inhibition concentration (IC50) was 200 mg/kg. In the presence of DOM, the eco-toxicity of phe could be alleviated and the inhabited degree was related to the content of hydrophobic components and surface activity. This effect could be strengthened by the high concentration of DOM. As a kind of hydrophobic organic compound, phe could reduce the moisture of topsoil, and DOM would slightly increase the moisture of topsoil polluted by phe. It was concluded that DOM could lighten the eco-toxicity of phe in soil.

A pot experiment showed that under NH2-N treatment, strong gluten wheat Yumai 34 had the highest root biomass, root activity, N use efficiency, N harvest index and grain protein content, but all of these were the lowest under NO3(-)-N treatment. For the medium gluten wheat Yumai 49, the items measured were the highest under NH4+-N treatment, but not the same trend under NO3(-)-N and NH2-N treatments. For the weak gluten wheat Yumai 50, NH4+-N treatment was the best for its top quality and specialized end-uses. There was a significant relationship between grain protein content and N harvest index.

The combined effects of Cu, Cd, Pb and Zn on the growth and activity of the seminal roots of wheat (Triticum aestivum) were studied by the method of quadratic regression revolution design. The mathematical models describing the above relations were established. As for the toxicity to the root vitality, their single effects, marginal utility and combined effects between two heavy metals were analyzed. The results showed that Pb had the most important effect on the activity of root, and then, Cu, Cd and Zn in sequence. The interaction between Cu and Cd, Cu and Zn, Zn and Cd, Cd and Pb had great effects on the activity of seminal roots. Furthermore, among the concentration range of 0 to 20 mg.L-1, as for Cu and Zn, the lowest density had the biggest marginal utility, while Cd and Pb had the biggest ones at the highest density.

A large-volume solution culture and a small-pot soil test were adopted to screen for aluminum tolerance in wheat. Significant correlations were observed between root and shoot tolerance indices in wheat genotypes by using the same or different screening method. It was also shown that root tolerance parameters such as relative root length (RRL) and relative root dry weight (RRW) had more sensitive for differentiating aluminum tolerance in wheat genotypes indicated by higher standard deviation (SD), coefficient of variation (CV), and distribution of data. Although shoot tolerance parameters, such as relative shoot length (RSL) and relative shoot dry weight (RSW) had less sensitive for differentiating aluminum tolerance within wheat genotypes indicated by lower SD, CV, and distribution of data, shoot growth parameters were reliable indicators of Al tolerance because they were sufficient to discriminate Al-tolerant and Al-sensitive genotypes in wheat. Shoot growth especially shoot length could be easily, rapidly, and non-destructively determined, and used effectively to screen for aluminum tolerance in a large-scale screening or breeding program.

Cadmium pollution in soil not only affects growth and yield formation of crop plants, but also develops a potential risk to food health. The experiment was conducted to study growth of Cd and mineral nutrient uptake of two wheat cultivars differed in agronomic performance in seedling stage under 5 Cd levels ranged from 0 to 1.0 mg.kg-1 Cd. The results showed that the growth and dry matter accumulation were stimulated in low Cd concentration (0.03 mg.kg-1) for both cultivars, while inhibited significantly under high concentration (> 0.3 mg.kg-1). The inhibited extension was dependence on cultivars and Genguo 534 had higher tolerance to Cd toxicity in comparison with E18513. There was the significant interaction between Cd level and cultivar in the influence of Cd treatment on Cd content in both root and shoot in that Genguo 534 had higher Cd content in lower Cd levels and E81513 showed more rapid increase in higher Cd levels. Cd treatment had significant influence on mineral nutrient uptake and two cultivars showed different response. In the treatment of 0.1 mg.kg-1 Cd, the contents of five macro-nutrients were significant lower for E81513 in comparison with those in control, while Genguo remained little changed.

The eco-toxicity of Cu, Zn, Pb, and Cd in the single form was tested with four types of soils(red loam soils, meadow brown soils, chestnut soils, and dark brown soils) and their combined effect was determined with meadow brown soils. The results showed that with the same content of heavy metals, the root elongation was strongly inhabited than the seed germination, and it indicated that root was more sensitive to heavy metals pollution. The inhibition rate of heavy metals pollution on the root elongation (IRHMRE) of wheat was significantly related with the contents of organic matter (OR) and Kjedahl-nitrogen (K-N) in soils (R2OR = 0.91, R2K-N = 0.92). However, IRHMRE was not significantly related with soil pH as did with OR and K-N, so does the content of CEC (R2pH = 0.62, R2CEC = 0.60). Whether under the low concentration of Cu, Zn, Pb, and Cd resulted in an irritated effect in root elongation, or under high concentration resulted in an inhibition effect in the single form, an synergistic effect occurred in the combined form.

The hydroponics experiment was conducted to study the nutrition basis for growth promotion of wheat by Enhanced Ammonium Nutrition(EAN). Compared with fertilizing NO3- alone, EAN significantly increased N concentration and accumulation in leaves, sheaths, and whole plant, but there were not significant effects on roots. EAN had no significant effects on concentration of P and K, but decreased that of Ca and Mg in whole plant. EAN increased accumulation of P, K, and Ca in whole plant, and decreased that of Mg, whereas single NH4+ decreased accumulation of all mineral nutrients. EAN had different effects on accumulation of mineral nutrients in different genotypes. Compared with fertilizing NO3- alone, EAN increased accumulation of P, K, and Ca of YM158 and LZ953. For the accumulation of JDM, there was little responsive to EAN. These results indicated that EAN promoted N absorption and increased accumulation of N, P, K, and Ca in whole plant.