洗涤厂排污口可培养中度嗜热菌的多样性

为考查洗涤厂热废水排放口土壤在常年人为热环境下的可培养嗜热菌的多样性,采集洗涤厂热废水排放口附近的湿热泥土,应用不同培养基分离纯化泥土中的可培养嗜热菌,并对获得的纯培养细菌进行16S rDNA鉴定和系统发育相关分析。结果表明：分离纯化得到的29株不同表型的纯培养菌株均属于坚壁菌门芽孢杆菌纲,归属于5个属11个种,分别是地芽孢杆菌属 Geobacillus 3个种,芽孢杆菌属 Bacillus 3个种,无氧芽孢杆菌属 Anoxybacillus 3个种,解脲芽孢杆菌属Ureibacillus 1个种和高温放线菌属 Thermoactinomyces 1个种,属种多样性丰富,菌株资源具有潜在开发应用价值。     

水稻条纹病毒外壳蛋白和病害特异蛋白在寄主体内的积累

ＰＡＳ ＥＬＩＳＡ检测结果表明：（１）水稻条纹病毒外壳蛋白和病害特异蛋白在水稻寄主体内累积量的变化趋势是一致的,而且均与寄主症状的严重度密切相关．（２）不同水稻品种中,２种蛋白的累积量和累积速率有明显差异．明恢６３（高感）２种蛋白的累积量均比ＩＲ３６（高抗）的明显大;０６３８１（耐受性低）２种蛋白的累积速率均比岗优２２（耐受性高）的明显快,０６３８１病叶中２种蛋白累积量在其显症３０ｄ左右达到高峰,而岗优２２的则在４０ｄ左右     

First record of the little fire ant,Wasmannia auropunctata (Hymenoptera: Formicidae), in Chinese mainland

In January 2022, we received ant specimens collected from three field colonies from Shantou City, Guangdong Province, China. They were identified as the little fire ant, Wasmannia auropunctata, through morphological and molecular analyses. Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union for Conservation of Nature (IUCN) and has spread from its native range in South America to every continent except Antarctica. DNA analysis of mitochondrial cytochrome c oxidase subunit I (COI) in nine specimens of W. auropunctata found that they had a close genetic relationship with specimens from Argentina. This study represents the first formal record of the establishment of W. auropunctata outdoor in Chinese mainland. However, the invasion stage and occurrence degree of W. auropunctata in China are not clear to date. The implementation of quarantine measures, investigation of the occurrence and distribution, and development of monitoring and control strategies are needed to actively respond to the threat posed by this highly invasive ant.     

西藏自治区首次发现螟黄赤眼蜂

为发掘西藏地区本土的赤眼蜂资源,本研究利用灭活米蛾卵卡在西藏林芝嘎玛地区的梨园采集到一个赤眼蜂种群。采用ITS2序列比对鉴定所采集的赤眼蜂种类,并测定该蜂的生物学指标。结果表明：西藏林芝嘎玛地区所诱集的赤眼蜂鉴定为螟黄赤眼蜂Trichogramma chilonis Ishii,羽化率为80%,雌性比为57.14%,耐饥饿时间为1.08 d,后足径节长度为157.6μm。本研究将为发掘西藏地区赤眼蜂资源提供参考,并为利用赤眼蜂在西藏自治区开展生物防治实践奠定基础。     

Effects of dietary lysozyme levels on growth performance,intestinal morphology,non‐specific immunity and mRNA expression in weanling piglets

The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non‐specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non‐specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.     

Automated identification of sugar beet diseases using smartphones

Cercospora leaf spot (CLS) poses a high economic risk to sugar beet production due to its potential to greatly reduce yield and quality. For successful integrated management of CLS, rapid and accurate identification of the disease is essential. Diagnosis on the basis of typical visual symptoms is often compromised by the inability to differentiate CLS symptoms from similar symptoms caused by other foliar pathogens of varying significance, or from abiotic stress. An automated detection and classification of CLS and other leaf diseases, enabling a reliable basis for decisions in disease control, would be an alternative to visual as well as molecular and serological methods. This paper presents an algorithm based on a RGB‐image database captured with smartphone cameras for the identification of sugar beet leaf diseases. This tool combines image acquisition and segmentation on the smartphone and advanced image data processing on a server, based on texture features using colour, intensity and gradient values. The diseases are classified using a support vector machine with radial basis function kernel. The algorithm is suitable for binary‐class and multi‐class classification approaches, i.e. the separation between diseased and non‐diseased, and the differentiation among leaf diseases and non‐infected tissue. The classification accuracy for the differentiation of CLS, ramularia leaf spot, phoma leaf spot, beet rust and bacterial blight was 82%, better than that of sugar beet experts classifying diseases from images. However, the technology has not been tested by practitioners. This tool can be adapted to other crops and their diseases and may contribute to improved decision‐making in integrated disease control.     

猪Ghrelin基因的克隆及原核表达

从猪下丘脑、胃等组织中提取总RNA，根据已发表的猪的Ghrelin mRNA序列设计合成引物，通过RT-PCR进行cDNA扩增，获得了282bp的片段。将该片段克隆于pMD-18T载体后进行序列分析，确认PCR产物为Ghrelin cDNA。从阳性克隆中提取质粒，经NheⅠ和XhoⅠ双酶切，回收282bp的目的片段，定向克隆到pET-28a表达载体中，提取质粒并再次转化到BL21（DE3）中，成功地筛选出阳性克隆。经IPTG诱导阳性菌，通过SDS-PAGE检测出猪Ghrelin基因的表达．     

Effect of Soil Organic Matter on Adsorption and Insecticidal Activity of Toxins from Bacillus thuringiensis

With the large-scale cultivation of transgenic crops expressing Bacillus thuringiensis (Bt) insecticidal toxin in the world, the problem of environmental safety caused by these Bt crops has received extensive attention. The effects of soil organic matter (SOM) on the adsorption and insecticidal activity of Bt toxin in variable- and constant-charge soils (red and brown soils, respectively) were studied. Organic carbon in the soils was removed using hydrogen peroxide (H_2O_2). After H_2O_2 treatment, the SOM in the red and brown soils decreased by 71.26% and 82.82%, respectively. Mineral composition of the H_2O_2-treated soils showed no significant changes,but soil texture showed a slight change. After SOM removal, the cation exchange capacity (CEC) and pH decreased, while the specific surface area (SSA), point of zero charge (PZC), and zeta potential increased. The adsorption isotherm experiment showed that the Bt toxin adsorption on the natural and H_2O_2-treated soils fitted both the Langmuir model (R~2≥ 0.985 7) and the Freundlich model (R~2≥ 0.984 1), and the amount of toxin adsorbed on the H_2O_2-treated soils was higher than that on the natural soils. There was a high correlation between the maximum adsorption of Bt toxin and the PZC of soils (R~2= 0.935 7); thus, Bt toxin adsorption was not only influenced by SOM content, but also by soil texture, as well as the SSA, CEC, PZC, and zeta potential. The LC_(50) (lethal concentration required to kill 50% of the larvae) values for Bt toxin in the H_2O_2-treated soils were slightly lower than those in the natural soils, suggesting that the environmental risk from Bt toxin may increase if SOM decreases. As the measurement of insecticidal activity using insects is expensive and time consuming, a rapid and convenient in vitro method of enzyme-linked immunosorbent assays is recommended for evaluating Bt toxin degradation in soils in future studies.     

海产品中副溶血弧菌的分离与鉴定

副溶血弧菌（Vibrio Paraaemolyticus)是一种致病性嗜盐菌，常引起人类食物中毒，通过对四种不同海产品的检测，发现该菌检出率很高，其中，海虾中的检出率高达90％，海产鱼为70％，贝类为60％，海蟹为40％，平均检出率为65％，动物试验证实，该菌致病性较强。