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Synthetic hexaploid wheat (SHW), possesses numerous genes for drought that can help breeding for drought-tolerant wheat varieties. We evaluated 10 root traits at seedling stage in 111 F9 recombinant inbred lines derived from a F2 population of a SHW line (SHW-L1) and a common wheat line, under normal (NC) and polyethylene glycol-simulated drought stress conditions (DC). We mapped quantitative trait loci (QTLs) for root traits using an enriched high-density genetic map containing 120370 single nucleotide polymorphisms (SNPs), 733 diversity arrays technology markers (DArT) and 119 simple sequence repeats (SSRs). With four replicates per treatment, we identified 19 QTLs for root traits under NC and DC, and 12 of them could be consistently detected with three or four replicates. Two novel QTLs for root fresh weight and root diameter under NC explained 9 and 15.7% of the phenotypic variation respectively, and six novel QTLs for root fresh weight, the ratio of root water loss, total root surface area, number of root tips, and number of root forks under DC explained 8.5–14% of the phenotypic variation. Here seven of eight novel QTLs could be consistently detected with more than three replicates. Results provide essential information for fine-mapping QTLs related to drought tolerance that will facilitate breeding drought-tolerant wheat cultivars.

On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index system to odor evaluation. An odor pollution indicator provides theoretical support for further modelling and evaluating odor pollution from sewage sludge composting facilities.

To study the characteristics and sources of trace metals in PM

Volatile organic compounds (VOCs) play very important roles in the formation of ozone and secondary organic aerosols. The concentrations, compositions, and seasonal variation of VOCs were measured in 2012 at Changbai Mountain Forest Ecosystem Research Station, a remote station in Northeast China. Weekly samples were collected in the Changbai Mountain area and analyzed via gas chromatography-mass spectrometry. The results showed that the annual mean concentration of total VOCs (TVOCs) was 10.7×10

Volatile organic compounds (VOCs) play important roles in the atmosphere as precursors of secondary air pollutants. The regional background concentrations and variation characteristics of VOCs in the atmosphere of southwestern China were studied. Meanwhile, a receptor model based on principal component analysis (PCA) was used to identify the major sources of VOCs. Weekly samples were collected in 2007 in the Gongga Mountain base station and analyzed with a three-stage preconcentration method coupled with GC-MS. The annual mean concentration of TVOCs and NMHCs were 9.40 x 10(-9) +/- 4.55 x 10(-9) and 7.73 x 10(-9) +/- 4.43 x 10(-9), respectively. Aromatic hydrocarbons provided the largest contribution to TVOCs (37.3%), follow by alkanes (30.0%) and halogenated hydrocarbons (19.8%), the smallest contribution was from alkenes (12.9%). Three major sources were resolved by the receptor model, traffic sources, biogenic sources and combustion sources. The seasonal variation of TVOCs in this area was obviously, and the order was autumnwinterspringsummer. TVOCs concentration in autumn was very significantly higher than that in summer (P0.01). The seasonal variation of the four types of VOCs showed different characteristics due to the differences in photochemical properties. Isoprene emissions were from biogenic sources. Regression analysis revealed a good exponential relationship between the isoprene concentration and temperature. High temperatures increased the isoprene concentrations. However, the isoprene concentration remained constant when the ambient air temperature was below 20 degrees C. The TVOCs in Gongga Mountain were at a medium level comparing with the results of other regions, and there was a clear background station emission characteristic.

In order to study the pollution status and the seasonal and diurnal variations, ambient concentrations of BTEX were analyzed at Beijing from 2008-10 to 2009-10, by using the method of two-step-concentration-gas spectrometry/mass (CCD-GC/MS). The average concentration of BTEX in Beijing was 13.9-44.0 microg x cm(-3). The dominant compound components were toluene, benzene, followed by ethyl benzene, m/p-xylene, o-xylene. Compared with foreign cities and regions, the level of BTEX at Beijing atmosphere was relatively lower. The study found that BTEX in Beijing mainly came from vehicle emissions, coal and solvent evaporation were also important sources of BTEX. No significantly obvious seasonal variation was observed, with the highest concentrations observed in spring and summer and the lowest concentrations generally found in autumn. Seasonal variations of emission sources were the main reason for seasonal changes of BTEX. However, the impact of weather factors on the BTEX can not be ignored, such as temperature and strong winds. Significant diurnal variations in BTEX were observed. The BTEX concentrations displayed a bimodal pattern, with peak between 08:00 and 10:00. and between 16:00 and 08:00. The minimum concentration generally appeared around 14:00.

In order to study the potential impact of volatile organic compounds (VOCs) in summer and autumn on region ozone, ambient concentrations and changes of VOCs were analyzed at Tangshan from June to September 2007 and 2008, by using the method of two-step-concentration-gas spectrometry/mass (CCD-GC/MS). The average concentration in Tangshan was 163.5 x 10(-9) C. The major components were alkanes, aromatics, alkenes and halogen hydrocarbons which accounted for 45.9%, 29.9%, 5.9% and 18.9% respectively. The average concentration decreased 51.9% compare with 2007 (340.4 x 10(-9) C), confine gas stations is the main reason of the decline of alkyl, the large decline is aromatic hydrocarbons, 67%, which has the most potential impact of ozone formation, and dichlorobenzene in industrial emissions has increased. The concentrations of VOCs in Tangshan were lower 8% than that of Beijing during the same period in 2008. The changes of VOCs during 2008 Beijing Olympic show that in addition to traffic source industrial emissions is also an important source of atmospheric pollution.

Volatile organic compounds (VOCs) is one of the key precursors of atmospheric ozone (O3), whose concentration variation influences directly the level of the photochemical pollutant O3. During Beijing Olympics, VOCs were measured near the Beijing National Stadium. Two and half-hour integrated canister samples were collected and analyzed in the morning and afternoon of each sampling day. Simultaneously, concentration, potential ozone production and sources of VOCs in the atmosphere of Beijing were studied. And the results indicated that the total VOCs species had higher concentrations in the morning (34.38 x 10(-9)), and lower in the afternoon (27.13 x 10(-9)), where the concentration of alkanes was the highest, and aromatics and alkenes came next. However, the concentrations of alkenes in the afternoon were significantly lower than those in the morning, which was 28%, and aromatics (26%) and alkanes (15%) came next. 1,2,4-Trimethylbenzene has the highest propylene-equivalent concentration (8.05 x 10(-9)C), and m/p-xylene (6.97 x 10(-9)C), toluene (6.41 x 10(-9)C) and 1,3,5-trimethylbenzene (5.64 x 10(-9) C) came next. Aromatics (47%) gives the most significant contribution to the production of O3 in the atmospheric VOCs of Beijing, and then were alkenes (40%) and alkanes (13%). Automobile emissions accounted for approximately 28% of the total VOCs, and solvent volatilization (19%), LPG leakage (15%) and industrial sources (12%) came next, from which Beijing may decrease the atmospheric VOCs.

In order to research on the air pollutants' long-range transportation in North China, aerosol samples were collected with Andersen cascade sampler at the summit of mount Tai during June 2006, in Shandong Province. The water soluble ionic concentrations were analyzed by IC. It shows that there are three types of size distribution: 1) ions whose mass resided mainly within the accumulation mode with the peak at 0.43-0.65 microm (SO4(2-), NH4+, K+); 2) Ions whose mass resided mainly within coarse particles with the peak at 4.7-5.8 microm (Ca2+, Mg2+); 3) Ions which were two modes with the peak at 0.43-0.65 microm and 4.7-5.8 microm (NO3-, NO3-,Cl-). The mass median diameter of SO4(2-) with high concentration is between 0.5 microm and 0.8 microm, and belongs to the "drop mode". The concentration of ions such as SO4(2-), NO3-, NH4+ and K+ has a huge variety and the sulfate has the most great variety with the lowest concentration which is 4.0 microg x m(-3) and the highest concentration which is 42.3 microg x m(-3). The ions (SO4(2-), NO3-, NH4+) reach the high value when the humid air mass comes from the south.