Wheat lines with shortened Th. ponticum chromatin carrying Fhb7 and molecular markers linked to Fhb7 will accelerate the transfer of Fhb7 to breeding lines and provide an important resource for future map-based cloning of this gene. Fusarium head blight is a major wheat disease globally. A major FHB resistance gene, designated as Fhb7, derived from Thinopyrum ponticum, was earlier transferred to common wheat, but was not used in wheat breeding due to linkage drag. The aims of this study were to (1) saturate this FHB resistance gene region; (2) develop and characterize secondary translocation lines with shortened Thinopyrum segments carrying Fhb7 using ph1b; (3) pyramid Fhb7 and Fhb1 by marker-assisted selection. Fhb7 was mapped in a 1.7 cM interval that was flanked by molecular markers XsdauK66 and Xcfa2240 with SSR, diversity arrays technology, EST-derived and conserved markers. KS24-2 carrying Fhb7 was analyzed with molecular markers and genomic in situ hybridization, confirming it was a 7DS.7el2L Robertsonian translocation. To reduce the Thinopyrum chromatin segments carrying Fhb7, a BC1F2 population (Chinese Spring ph1bph1b*2/KS24-2) was developed and genotyped with the markers linked to Fhb7. Two new translocation lines (SDAU1881 and SDAU1886) carrying Fhb7 on shortened alien segments (approximately 16.1 and 17.3% of the translocation chromosome, respectively) were developed. Furthermore, four wheat lines (SDAU1902, SDAU1903, SDAU1904, and SDAU1906) with the pyramided markers flanking Fhb1 and Fhb7 were developed and the FHB responses indicated lines with mean NDS ranging from 1.3 to 1.6 had successfully combined Fhb7 and Fhb1. Three new molecular markers associated with Fhb7 were identified and validated in 35 common wheat varieties. The translocation lines with shortened alien segments carrying Fhb7 (and Fhb1) and the markers closely linked to Fhb7 will be useful for improving wheat scab resistance.

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A solution culture experiment was conducted to investigate the effect of silicate on the yield and arsenate uptake by rice. Rice seedlings (Oryza sativa L. cv. Weiyou 77) were cultured in modified Hoagland nutrient solution containing three arsenate levels (0, 0.5 and 1.0 mg L )1 As) and four silicate levels (0, 14, 28 and 56 mg L )1 Si). Addition of Si significantly increased shoot dry weight (P ¼ 0.001) but had little effect on root dry weight (P ¼ 0.43). Addition of As had no significant effect on shoot dry weight (P ¼ 0.43) but significantly increased root dry weight (P ¼ 0.01). Silicon concentrations in shoots and roots increased proportionally to increasing amounts of externally supplied Si (P < 0.001). The presence of As in the nutrient solution had little effect on shoot Si concentration (P ¼ 0.16) but significantly decreased root Si concentration (P ¼ 0.005). Increasing external Si concentration significantly decreased shoot and root As concentrations and total As uptake by rice seedlings (P < 0.001). In addition, Si significantly decreased shoot P concentration and shoot P uptake (P < 0.001). The data clearly demonstrate a beneficial effect of Si on the growth of rice seedlings. Addition of Si to the growth medium also inhibited the uptake of arsenate and phosphate by the rice seedlings.Abbreviation: ICP-OES -inductively coupled plasma-optical emission spectrometer

The origin of angiosperms has been a long-standing botanical debate. The great diversity of angiosperms in the Early Cretaceous makes the Jurassic a promising period in which to anticipate the origins of the angiosperms. Here, based on observations of 264 specimens of 198 individual flowers preserved on 34 slabs in various states and orientations, from the South Xiangshan Formation (Early Jurassic) of China, we describe a fossil flower, Nanjinganthus dendrostyla gen. et sp. nov.. The large number of specimens and various preservations allow for an evidence-based reconstruction of the flower. From the evidence of the combination of an invaginated receptacle and ovarian roof, we infer that the seeds of Nanjinganthus were completely enclosed. Evidence of an actinomorphic flower with a dendroid style, cup-form receptacle, and angiospermy, is consistent with Nanjinganthus being a bona fide angiosperm from the Jurassic, an inference that we hope will re-invigorate research into angiosperm origins.

a b s t r a c tDiclofenac is a common anti-inflammatory drug. Its electrochemical degradation at boron doped diamond electrode was investigated in aqueous solution. The degradation kinetics and the intermediate products were studied. Results showed that electro-oxidation was effective in inducing the degradation of diclofenac with 30 mg/L initial concentration, ensuring a mineralization degree of 72% after a 4 h treatment with the applied bias potential of 4.0 V. The effects of applied bias potential and addition of NaCl on diclofenac degradation were investigated. Different degradation mechanisms of diclofenac were involved at various applied bias potentials. With the addition of NaCl, some chlorination intermediates including dichlorodiclofenac were identified, which lead to the total organic carbon increase compared with the electrolysis process without NaCl addition at the reaction initial period. The main intermediates including 2,6-dichlorobenzenamine, 2,5-dihydroxybenzyl alcohol, and benzoic acid are identified at the time of 2 h. 1-(2,6-Dichlorocyclohexa-2,4-dienyl)indolin-2-one were also identified. These intermediates disappeared gradually with the extension of reaction time. Small molecular acids were identified finally. Based on these results, a degradation pathway of diclofenac was proposed.

a b s t r a c tA combined bioelectrochemical and sulfur autotrophic denitrification system (CBSAD) was evaluated to treat a groundwater with nitrate contamination (20.9-22.0 mg NO À 3 -N/L). The reactor was operated continuously for several months with groundwater to maximize treatment efficiency under different hydraulic retention times (HRT) and electric currents. The denitrification rate of sulfur autotrophic part followed a half-order kinetics model. Moreover, the removal efficiency of bioelectrochemical part depended on the electric current. The reactor could be operated efficiently at the HRT ranged from 4.2 to 2.1 h (corresponding nitrogen volume-loading rates varied from 0.12 to 0.24 kg N/m 3 d; and optimum current ranged from 30 to 1000 mA), and the NO À 3 -N removal rate ranged from 95% to 100% without NO À 3 -N accumulation. The pH of effluent was satisfactorily adjusted by bioelectrochemical part, and the sulfate concentration of effluent was lower than 250 mg /L, meeting the drinking water standard of China EPA.

The present study investigated the cyanobacteria and one family of their toxins-microcystins (MCs) in Guanting Reservoir of Beijing, China. The dominant species in the cyanobacteria found in August and September of 2006 was Microcystis, which accounted 99% of total algal cells. The specific species of the Microcystis in the cyanobacteria included Microcystis ichthyobalbe, Microcystis novacekii, Microcystis botrys and Microcystis aeruginosa which had different ratios in different sites. The qualitative analysis by HPLC showed that two microcystins were contained in cyanobacteria and one microcystin was in water of the reservoir. The major microcystins were microcystin-RR (MC-RR) and microcystin-LR (MC-LR), but only MC-LR was detected in water. The quantitative analysis by HPLC indicated that the maximum concentrations of MC-RR and MC-LR contained in cyanobacteria were 0.74 and 0.41 mg/g dry weight, respectively. The maximum microcystin concentration in water was 1.15 g/L and others were below 1 g/L.

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