A simple and efficient method for isolating small RNAs from different plant species

Background  

Small RNAs emerged over the last decade as key regulators in diverse biological processes in eukaryotic organisms. To identify and study small RNAs, good and efficient protocols are necessary to isolate them, which sometimes may be challenging due to the composition of specific tissues of certain plant species. Here we describe a simple and efficient method to isolate small RNAs from different plant species.     

Analysis of gene cassettes of streptomycin-spectinomycin resistance of Hungarian Salmonella enterica serotype Typhimurium strains

By PCR using the ant(3")-Ia primer pair the aadA gene was detected in 34 streptomycin- and spectinomycin-resistant Salmonella enterica serotype Typhimurium strains. Out of them 12 belonged to DT104 and 22 to non-DT104 phage type. Using different primer combinations it was demonstrated that this gene was integron-associated in all cases: in the DT104 strains it was generally contained by a 1 kb integron while in the majority of the non-DT104 strains by a 2.05 kb (less often by a 1.9 or 1 kb) integron. In the case of integrons carrying multiple cassettes the cassette containing the aadA gene was located closer to the 3' end of the integron. The aadA genes of DT104 and non-DT104 strains were different: in the former group the aadA2 gene, while in the latter group (constituted by strains of five different phages types as well as unclassifiable and untypable strains) the aadA1 gene could be identified. The RH50/RH51 primer pair described by Collis and Hall (1992) proved to be suitable for rapid discrimination between the aadA1 and aadA2 genes on the basis that the RH51 primer bound exclusively to the aadA2 gene.     

Growth of Daphnia magna on urban wastewaters tertiarily treated with Scenedesmus sp.

The productivity and composition of Daphnia magna were measured for high density populations grown in 5-litre flow-through tanks supplied with a tertiary effluent. This effluent was urban secondary wastewaters biologically treated with intensive cultures of a microalga Scenedesmus sp.Three daily feeding rates (575, 1150, 1750 mg dry weight algae day^?1 tank^?1), obtained by adjusting the flow of a tertiary effluent containing 115 mg dry weight of algae litre^?1, allowed average productions of 0·9, 1·6 and 2·6 g of Daphnia (wet basis) litre^?1 week^?1 which were proportional to the rations. When the flow of tertiary effluent was increased to 40 litres day^?1 tank^?1 (ad libitum), the average yield rose to 3·6 g of daphnids (wet basis) litre^?1 week^?1. The maximum population reached 48 000 individuals litre^?1. The daphnid/algae evergy conversion ratio was 0·4. Algae were removed by Daphnia at a maximum efficiency of 95%. The composition of Daphnia biomasses was 59·5% protein, 9·5% fat and 5·6% carbohydrate on a dry weight basis. No deficiencies in methionine and linolenic acid were noted.Results indicated the remarkable potential of urban wastewaters for the production of protein and the high productivity of Daphnia magna.     

优质厚皮甜瓜新品种好运8号的选育和栽培技术?

好运8号是广西农科院园艺研究所为适应南方湿热地区厚皮甜瓜栽培对品种的要求,利用逆环境定向选育,以自交系HN14-d作母本,TY8-a作父本杂交配制成的一代杂种。果实椭圆形,皮色橙黄有绿色斑块,网纹中等,一般单瓜重2.0kg,果肉橙红偏黄,皮肉厚约3.5cm,质地脆嫩蜜甜,有淡香,口感佳,中心可溶性固形物含量15~16%,全生育期春茬110d左右,秋茬90d左右,果实发育期45d左右,商品性好,一般产量36t/hm2,植株长势较强,易座果,较耐白粉病、霜霉病,抗蔓枯病能力中等,适于南方地区保护地种植。2007年3月通过广西农作物品种审定委员会审定     

Discrimination of lithogenic and anthropogenic influences on topsoil magnetic susceptibility in Central Europe

The study was performed on the area of the three countries involved in the MAGPROX project (Poland, Czech Rep., Germany). In the first stage the basic map of magnetic susceptibility based on the field topsoil measurement was compiled with an average grid density of 10 km. In the second stage of the study, vertical distribution of magnetic susceptibility of ca. 600 topsoil cores (0.3 m long), collected over central Europe, was examined with respect to the anthropogenic or lithogenic influence on magnetic susceptibility of the soil surface, with the focus being on the interpretation of the areas showing high surface susceptibility values. The maximum values were mostly observed in depths of 3–4 cm. In general seven different types of susceptibility profiles from forest areas and one typical for urban soil are presented. They are a result of a combination of natural (litho- and pedogenic) and anthropogenic contributions. Our results prove that soil profiles, dominated by anthropogenic influence due to atmospherically deposited dust, are characterized by magnetically enhanced humuous layer, corresponding to layer with the highest concentration of heavy metals. Moreover, forest soils show in these cases higher magnetic susceptibility than soils in open areas (grassland, meadows or arable soils).     

The Science of Managing Forests to Sustain Water Resources

Water, Air, &; Soil Pollution -     

QuEChERS multiresidue method validation and mass spectrometric assessment for the novel anthranilic diamide insecticides chlorantraniliprole and cyantraniliprole

The gas-phase dissociation reactions of chlorantraniliprole (Rynaxypyr) and cyantraniliprole (Cyazypyr) have been studied in triple-quadrupole, ion trap, and orbitrap mass spectrometers equipped with electrospray and desorption electrospray ion sources, revealing the formation of odd-electron fragment ions, the structures of which were elucidated. The odd-electron fragments were unusually abundant, and their formation is proposed to occur via a tricyclic intermediate. The applicability of the QuEChERS multiresidue method for the quantitation of chlorantraniliprole and cyantraniliprole was also assessed in this study. Four matrices representative of oily, watery, acidic, and dry crop groups were tested, with a targeted limit of quantitation (LOQ) of 0.01 mg/kg. Average recoveries ranged between 87 and 107%, with relative standard deviations (RSD) of ≤ 8%. Linear calibration functions with correlation coefficients r > 0.99 were obtained. The study provides an expansion of the QuEChERS method to include anthranilic diamides and a mass spectrometric assessment for these two novel agrochemical active ingredients.     

长江三峡库区及上游地区林业生态工程建设途径及对策分析

长江三峡库区及上游地区是一个生态环境比较脆弱并逐步恶化的区域,虽经长江中上游防护林工程十年的治理,但未得到根本控制和改善,这与三峡工程建设,中西部区域及至长江流域的经济建设及可持续发展均不协调,与我国高速发展的经济也不协调。而面临诸多突出的生态问题是与区域林业生态建设严重滞后紧密相关的。本文针对三峡库区及上游地区自然、社会、经济状况、在总结和分析区域林业生态建设经验、问题的基础上,提出三峡库区及上     

滴灌成套设备和低压大流量滴头研制与应用

经过10多年的科学研究,我国在微灌设备研制方面取得了一定进展,先后生产试制了微灌用聚乙烯管材与管件,研制出了一批灌水器和过滤、施肥装置,促进了微灌技术的推广运用。对微管灌水器进行的系列化研究,降低了工程造价,提高了灌水质量。