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Soil microbiomes contribute to plant growth, health and agricultural production. However, the influence of long-term application of different fertilizers on soil microbial diversity and community structure of tea (Camellia sinensis) plantations remains unclear. Here it was hypothesized that organic fertilizer treatment (OF) would significantly improve the microbial diversity and alter the microbial community structure, leading to the support of more soil ecosystem functions in tea plantation. To test this, we investigated microbial communities of tea plantation soils under different long-term fertilization treatments using both high-throughput 16S rRNA gene Illumina sequencing and molecular ecological network analysis. Soil samples (Red soils, classified as Haplic Acrisol) were collected from 5 large experimental tea plantations under different long-term fertilization treatments (organic fertilizer (OF), chemical fertilizer (CF) and non-fertilizer (NF)) in central south of China in August 2017. Soils under OF treatment had higher microbial diversity compared with soils under other treatment regimes. Unweighted principal coordinate analysis (PCoA) results revealed a clear separation among the groups of tea plantation soils under the three treatment regimes. Relationship analysis between soil properties and microbial communities showed that pH and nitrate nitrogen (NO3-N) concentration were key physicochemical factors that significantly influenced microbial diversity and community structure. Furthermore, network analysis indicated that the network of OF treatment soils contained more functionally interrelated microbial modules than soils with CF treatment and that the topological roles of characteristic microorganisms and key microbial organisms were significantly different between CF and OF treatments. Relative to CF treatment, the relative abundances of organisms belonging to chemoheterotrophy, fermentation, nitrogen fixation, and aerobic nitrite oxidation functional groups in tea plantation soils under OF treatment were significantly increased by 28.74%, 110.10%, 41.16% and 556.64%, respectively (p

The effects of coumarins have been studied on seedling rate,stem and leaf dry weight and root dry weight of the tested rice,as well as defense enzymes,soluble protein content,chlorophyll content and proline content with coumarins (peucedanocoumarin Ⅲ,PeucedanocoumarinⅡ,pteryxin) (1,5,10,50,100 mg/L).The coumarin compounds have been used to treat the early rice combination Peiliangyou500 with low temperature stress of(5±1) ℃.The results showed that three coumarin compounds could make seedling rate,stem and leaf dry weight and root dry weight of the tested rice significantly higher than control,and the effect of 50 mg/L was the best.50 mg/L coumarin compounds made peroxidase,superoxide dismutase,catalase active and soluble protein content,chlorophyll content.Proline accumulation also increased under low temperature stress.

The braconid male genitalia can be used to identify closely-related species. After studying nearly 60 years’ male genitalia, the author summarizs the results of 256 braconid species which are grouped into 114 genera and 28 subfamilies. The structure of male genitalia, its application in species description and the phylogenetic analysis are introduced. Two groups of braconid male genitalia of subfamilies of the family Braconidae are also discussed. This paper further demonstrates that the character distribution of plesiomorphic character-state and apomorphy character-state of male genitalia of subfamilies are "sandwiched" and influenced by the parallelisms.

This report describes photochemical behaviors of pyrazosulfuron-ethyl in aqueous solution. The photodegradation of pyrazosulfuron-ethyl for the first time was investigated in aqueous solution at two different irradiation wavelengths and pH values ranging from 2.00 to 10.00. Results show that the rate of photodegradation was faster in acidic medium than that in basic medium, when pyrazosulfuron-ethyl was in neutral form. The half-lives of pyrazosulfuron-ethyl under ultra-violet light and simulated sunlight were found to be 27.17 and 153.33 min, respectively. The reactions followed first-order kinetics. The degradation pathways were proposed according to the identification results of photoproducts: carbon-sulfur and nitrogen-sulfur cleavages and photohydrolysis of the sulfonylurea bridge. It was concluded that photodegradation behaviors can occur within the sulfonylurea family, depending on the pH values of aqueous solution and the irradiation wavelengths. Este trabalho descreve o comportamento fotoquímico do pirazosulfuronato de etila em soluções aquosas. A fotodegradação do pirazosulfuronato de etila foi investigada pela primeira vez em dois comprimentos de onda de irradiação diferentes e valores de pH variando de 2,00 a 10,00. Os resultados mostram que a taxa de fotodegradação foi mais rápida em meio ácido do que em meio básico, quando pyrazosulfuron-etil estava na forma neutra. Os tempos de meia-vida do pirazosulfuronato de etila sob luz ultravioleta e luz solar simulada foram 27,17 e 153,33 min, respectivamente. As reações seguiram cinética de primeira ordem. As rotas de degradação foram propostas de acordo com os resultados de identificação dos fotoprodutos: clivagens carbono-enxofre e nitrogênio-enxofre e fotohidrólise da ponte de sulfonilureia. Concluiu-se que comportamentos de fotodegradação podem ocorrer dentro da família de sulfonilureia, dependendo dos valores de pH da solução aquosa e dos comprimentos de onda de irradiação.

The purpose of this paper is to develop a sensitive and low cost optical sensor for screening ametryn using bare gold nanoparticles (Au NPs). Based on the distance-dependent optical properties of Au NPs, the presence of ametryn could rapidly induce the aggregation of gold nanoparticles, thereby resulting in red-to-deep blue color change. The concentration of ametryn was determined with a limit of detection (LOD) lower than 1×10-6 M by the naked eyes and could be further monitored by a UV-vis spectrometer easily. The highest selectivity was achieved in comparison with other eleven pesticides with similar molecular structure, and the possible underlying mechanism was investigated by the simultaneous addition of tiopronin and ametryn in Au NPs solution.

In this paper, glutathione (GSH)-capped gold nanoparticles (GSH-GNPs) were prepared in water media and used for the colorimetric assay of Ca2+. GSH could quickly bind onto the GNP surfaces through its –SH group and the cross-linking of GSH-capped GNPs could be quickly achieved by chelation by its functional groups (–NH2 and–COOH) upon the addition of Ca2+. Color changes were observed from red to blue (or purple) within minutes with the increased concentration of Ca2+, in response to surface plasmon absorption of dispersed and aggregated nanoparticles. Using this colorimetric sensor, the concentration of Ca2+ was determined with a limit of detection low than 1×10−7 M by the naked eye and could further be monitored by a UV-vis spectrometry easily. The possible mechanism of the aggregated GSH-GNPs was discussed by the addition of ethylene diaminetetraacetate (EDTA) and Ca2+ in different orders.

In this paper, a highly sensitive and low cost optical sensor of cyromazine was prepared and used to the colorimetric detection using bare gold nanoparticles (Au NPs). Based on the distance-dependent optical properties of Au NPs, the presence of cyromazine could rapidly induce the aggregation of gold nanoparticles, thereby resulting in red-to-deep blue color change. The concentration of cyromazine was determined with a limit of detection (LOD) lower than 1 mg/L by the naked eyes and the sensitivity could be enhanced by the adjustment of ion strength and pH. The highest selectivity was obviously achieved with an absorption ratio (A640/A520) greater than 0.9. Moreover the possible underlying mechanism was discussed.