Mercury (Hg) is one of the major pollutants in soils because of the annual import of toxic Hg into the agricultural lands. The aims of the present studies are to investigate the effect of Hg on chlorophyll content in winter wheat var. jinan No. 17. Moreover, calcium (Ca) levels and bioaccumulation of Hg in wheat leaves were studied with the technique of inductively coupled plasma sector field mass spectrometer (ICP-SF-MS). The study conducted a range of Hg concentrations from 0~500 mg Hg/kg in the dry weight soil. The soil was artificially contaminated with Hg as follows: 0, 100, 200, and 500 mg Hg/kg as HgCl2. At early stages of the wheat growth, both low and high concentration of Hg stimulates chlorophyll content, but inhibits chlorophyll content at later stages of the wheat growth. Furthermore, the concentrations of Ca and Hg in wheat leaves increased with the increasing concentration of Hg on the thirty-fourth day with the technique of ICP-SF-MS. The results indicate that Hg can accelerate the absorption of Ca in winter wheat and Hg stress may affect Ca levels in wheat leaves.

The effect of 5-azacytidine (5-azaC) on the alleviation of damaging effects of NaCl treatment was studied in two wheat (Triticum aestivum L.) cultivars differing in salt tolerance (salt-tolerant Dekang-961 and sensitive Lumai-15). The plants were pre-treated or not with 50 μM 5-azaC and then subjected to salt stress induced by 100 or 150 mM NaCl. Salinity caused reduction in biomass accumulation and increase in malondialdehyde content in root tissues in both cultivars, but less in pre-treated seedlings. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the roots of both cultivars increased during salt stress, but the rate of increase was higher in Dekang-961. Plants treated with 5-azaC had higher root SOD, CAT and POD activities under salt stress than untreated plants. Content of 5-methylcytosine (5mC) decreased in both cultivars under salt stress, and the level of demethylation was higher in Dekang-961 than that in Lumai-15. Moreover, the degree of methylation was lower in both cultivars under salt stress after 5-azaC application compared to only salt-treated groups. These findings suggested that 5-azaC could protect plants from salt stress.

Spring wheat var. Vánek was cultivated in pots in a soil naturally contaminated with heavy metals. Experimental plants were treated with three different types of brassinosteroids (BRs; 24-epibrassinolide, 24-epicastasterone and 4154) during two different growth stages 29-31 DC (off shooting) and 59-60 DC (beginning of anthesis). Content of heavy metals (Cu, Cd, Pb and Zn) was determined using AAS method in the plant growth stages 47-49 DC (visible awns), 73-75 DC (30-50% of final grain size) and 90-92 DC (full ripeness). At the stages 47-49 DC and 73-75 DC, the content of the heavy metals was determined in the biomass of whole plants, while at the stage 90-92 DC it was determined separately in straw and grains. After the treatment of plants with BRs a decrease in heavy metals content was observed in the growth stage 73-75 DC (i.e. during the period when the plants are harvested for ensilage purposes. Likewise, a decrease of lead content in the grains by 70-74% in the plants treated at both stages 29-31 DC and 59-60 DC and by 48-70% in the plants of the third group (plants treated at stage 59-60 DC) was determined as compared with the untreated plants.

The experiments were laid out to understand the mechanisms causing yield limitations imposed by post-anthesis water and nitrogen deficiencies in plants with modified source-sink ratios. Two soil-water regimes were allotted to the main plots. At anthesis, three levels of N were applied: none, 25% and 50% of total the N supply. Spike-halving caused reduction in grain yield at both water regimes and all N supply levels, showing that the reduction in grain number can not be compensated by a higher individual grain weight. Sink reduction by trimming 50% of the spikelets reduced grain number per ear by 38.5% and increased individual grain weight by 12.0%, which shows the plasticity in grain weight and grain set of wheat if sufficient assimilates are available. Additional nitrogen supply at anthesis had no significant effect on the total aboveground biomass, but increased grain yield through more allocation of dry matter to grains. Our findings suggest that for rainfed wheat with optimum N supply and supplemental irrigation, wheat growers should choose cultivars with a high grain number per ear and manage the crop to increase grain number per unit of land (sink capacity).

The effects of diet type (wheat- or maize-based) and concentration of available phosphorus (AP; about 4, 3 and 2 g/kg) on the parameters of hen performance and egg quality as well as shell calcium (Ca) and phosphorus (P) contents were examined. Two experiments were carried out in which 240 and 120, respectively, older ISA Brown hens were housed in enriched cages. The interaction of diet type and AP concentration was ascertained for all evaluated characteristics except the amount of Ca and P deposited in shells in the first experiment. In the second experiment, the interaction of diet type and AP concentration was found for feed intake, egg weight, shell thickness and weight as well as the albumen quality parameters. Furthermore, Ca deposition in shells increased (P < 0.001) with the wheat diet. Hens fed a maize-based diet (P < 0.001) laid heavier eggs. The highest level of AP (4.1 g/kg) in the wheat-based diet significantly (P < 0.001) decreased albumen height, albumen index and Haugh units (HU). These trends were the same in both experiments. The results indicate that 0.27% AP in wheat-based diet and 0.30% AP in maize-based diet are adequate for hens with the intake 115 g of feed with 3.5% of Ca without a negative impact on performance or egg quality.

This experiment was conducted to achieve a high performance and compatible six promising lines of wheat, derived from experiments with a uniform global climate warm. The experiment was designed as randomized complete block design (RCBD) with four replications in the two regions of Sarchahan and Haji Abad. Shiroudi and Chamran cultivars were as control checks. Statistical analysis showed that the significant difference (P0.01) among treatments for grain yield in both region of Sarchahan and Haji Abad. The highest yield in both regions was obtained from S-78-11 line,with average yield of 7208 kg ha-1 and 8683 kg ha-1 for Sarchahan and Haji Abadregion regions, respectively. yield components analysis showed that thousand kernet weight had significant difference (P0.05) in Sarchahan and Haji Abad regions and the highest mean for 1000 kernal weight was 41.4 g for S-83-3 line and 39.3 g for Chamran cultivar in Haji Abad and Sarchahan, respectively. For two regions, also, there was significant difference (P0.01)in spike and number of seeds per spikelet. Differences in the spikelet numbers per Spike in Sarchahan region was significant (P0.01).

Little information has been known on greenhouse gas emissions from the unique purplish farmland that produces rice for more than 100 million people in Southwest China. We studied methane (CH4) and nitrous oxide (N2O) emissions under four wheat straw application rates (0, S0; 5.310, S1; 10.620, S2 and 21.240 kg/ha, S3) to a purplish paddy field (Regosols in FAO taxonomy) with the static chamber technique. The seasonal accumulative CH4 (TCH4) or N2O emissions from S0, S1, S2 and S3 were 255, 417, 571 and 687 kg/ha or 3.22, 2.66, 2.35 and 2.16 kg/ha during period from June 1 to September 14, 2005, respectively. Seasonal accumulative CH4 emission was significantly correlated with straw application (Xstraw) (TCH4 = 290.72 + 0.02 Xstraw, r2 = 0.93, P < 0.05). Significantly positive linear correlation was displayed between CH4 flux rate and soil temperature at 5 cm depth (Tsoil) (P < 0.05, 18.0°C ≤ Tsoil ≤ 26.4°C). Straw application less than 5.300 kg/ha could enhance plant carbon fixation amounts, whilst both CH4, N2O emissions and the ratio of carbon equivalent emission to carbon fixation were not increased in the purplish paddy soil.

The influence of temperature and species origin on the in vitro growth rate and pathogenicity of Fusarium and Microdochium nivale (F. avenaceum, F. culmorum, F. graminearum, F. poae, and M. nivale) to wheat seedlings was examined. The mycelial growth of Fusarium avenaceum, F. culmorum, F. graminearum, and F. poae was the fastest at 25°C, and of M. nivale at 15°C. The isolates of F. culmorum, F. graminearum and F. poae originating from mountain regions grew significantly faster at 15°C than those from flatland regions. The isolates from flatland regions grew significantly faster at 25°C than those from mountain regions. F. culmorum and F. graminearum were the most pathogenic species to the root development. The retardation of wheat grain germination caused by the tested species was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae. The biomass growth retardation at 15°C was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae; at 25°C as follows: F. graminearum, F. culmorum, F. avenaceum, M. nivale, F. poae. The isolates of M. nivale and F. poae originating from mountain regions were significantly more pathogenic than those from flatland regions. The results suggest that there exist different temperature ecotypes and pathotypes of Fusarium species and Microdochium nivale across the territory of the Slovak Republic.

il., bibliogr., streszcz., sum.

In this study,4 promising bread wheat lines of moderate zone that had been selected from E.R.W.Y.T (Elite regional wheat yield trial) with checks (Pishtaz , Bahar,shiraz) were evaluated in farmers conditions in Tehran province as on farm trial in 2009- 2010.Investigated genotypes were planted in 24 m2 plots and the experimental design was RCBD with three replications . Results showed that there was no significant difference among the genotypes for grain yield .However line M-86-3 with 5558kg/ha was outstanding. Quality of the investigated genotypes was also evaluted and there was differences among the investigated germplasm.