Damage by vertebrates to plastic irrigation pipes in Israel

Plastic irrigation pipes are damaged in Israel by vertebrates — both mammals and birds — of the following species: Aves: Piciformes, Picidae —Dendrocopos syriacus. Mammalia: Rodentia —Mus musculus, Rattus rattus alexandrinus, Nesokia indica, Spalax ehrenbergi, andHystrix indica; Carnivora: Canidae —Canis familiaris, C. aureus, andVulpes vulpes; Mustelidae —Meles meles; Viveridae —Herpestes ichneumon; Artiodactyla, Suiformes: Suidae —Sus scrofa. It is assumed that the reasons these vertebrates attack and damage the pipes are the excitement regulation mechanism; the habit of gnawing or pecking; playing; and a search for drinking water.     

The occurrence of callose during the process of local lesion formation

Callose depositionwas studied in relation to the development of local lesions using various virus-host combinations. Fluorescent spots due to callose formation at the initial sites of infection could be detected several hours before local lesions appeared in the combinationsNicotiana glutinosa — tobacco mosaic virus; ‘Samsun NN’ tobacco and ‘Pinto’ bean — tobacco mosaic virus and tobaco necrosis virus; ‘Pinto’ bean — cowpea mosaic virus. The fluorescent spots enlarged with time, and covered the lesion areas. Following the development of lesions the fluorescence decreased and was then to be seen only around the lesions. It eventually disappeared when the necrosis of cells in the lesions was complete. Strong callose fluorescence was also seen in veins near the lesions. In some cases fluorescence remained after local lesions had turned completely brown. When ‘Samsun NN’ tobacco was studied with tomato spotted wilt, tobacco rattle and tomato black ring viruses, which produce systemic necrosis as well as local lesions on the inoculated plants, similar callose fluorescence could be detected prior to local lesion formation. Here also, the fluorescence was clear during the early stages of lesion formation and grew weaker as lesion formation progressed, though in these cases no fluorescence was seen in veins near the lesions. The relation between callose deposition in and outside the local lesions and the restriction of virus movement from these tissues is discussed.     

中国番木瓜曲叶病毒在南宁的发生及其烟粉虱传播和中间寄主初步研究

番木瓜曲叶病毒病在广西南宁市郊区发生严重并造成很大经济损失,经2002-2004年调查,重病果园发病率高达47.23%-100%,染病番木瓜矮缩,叶片向下卷曲,叶背部叶脉增生,叶柄扭曲,早期染病植株无法开花结果。番木瓜曲叶病毒病可以通过烟粉虱传染,但是,室内人工传染效率很低,仅为8.33%;用PCR方法从表现黄脉症状的胜红蓟(Ageratum conyzoides)和田麻(Corchoropsis tomentosa)及表现黄曲叶症状的番茄(Lycopersicon escu-lentum)中检出中国番木瓜曲叶病毒(PaLCuCNV),证明这3种植物是番木瓜曲叶病毒病的中间寄主。     

生防菌解淀粉芽胞杆菌Lx-11悬乳剂研制及其对水稻白叶枯病的防治效果评价

目前已经登记的芽胞杆菌微生物杀菌剂剂型以悬浮剂和可湿性粉剂为主，剂型相对比较单一，为进一步提高货架期和利用效率，以解淀粉芽胞杆菌Lx-11作为研究对象，筛选出纳米材料作为载体，添加各种不同功能性助剂，在高速均质机的作用下剪切、均质，研制出解淀粉芽胞杆菌Lx-11悬乳剂。解淀粉芽胞杆菌Lx-11悬乳剂配方：发酵液70%～80%，吸附载体白炭黑10%～15%，大豆油30%～50%，乳化剂Span80和Tween80复配6%～10%，分散剂脂肪醇聚氧乙烯醚羧酸钠1%～3%，防冻剂乙二醇2%～4%，增效助剂SY-6535 1.5%～2.5%。该制剂的性能指标为：活菌体含量大于8×10⁸cfu/mL，悬浮率大于85%，粘度225 mPa·s，热贮稳定性合格；各项技术指标均符合产品标准要求。田间药效试验表明：解淀粉芽胞杆菌Lx-11悬乳剂对水稻白叶枯病的防治效果显著高于其发酵液。     

Residualwirkung von Chlortriazin-Herbiziden im Boden an drei rumänischen Standorten. II. Prognose möglicher Folgekulturen bei Atrazinrükständen im Boden

Residual effects of chlorotriazine herbicides in soil at three Rumanian sites. II. Prediction of the phytotoxicity of atrazine residues to following crops Total and plant-available atrazine residues in the top 10 cm soil were measured 120 days after application of 3 kg ai ha^?1 to maize (Zea mays L.) at three sites in Rumania. At one site, similar measurements were made 3?5 years after application of 100 kg ai ha^?1. Plant-available atrazine residues were estimated by extraction of soil samples with water, and by bioassay using Brassica rapa as the test plant. It was calculated that between 30 and 120μg atrazine 1^?1 was potentially available to plants in the different soils. Dose-response relationships for atrazine and the most important rotational crops with maize in Rumania—sunflower, winter wheat, soybean and flax—were determined in hydroponic culture using herbicide concentrations corresponding with the plant-available fractions measured in the different soils. ED₅₀ values were determined by probit analysis and the results showed that sunflower (ED₅₀, 22μg 1^?1) was the most sensitive crop, and soybean (ED₅₀, 78μg 1^?1) was the least. The residual phytotoxicity of atrazine to succeeding crops in the different soils was predicted using the appropriate availability and phytotoxicity data, and the results showed good agreement with those observed. The results suggest that measurements of plant-available herbicide residues afford a rapid method of assessing possible phytotoxicity to following crops.     

Inheritance of two body color mutations of the spiny bollworm (Earias insulana)

Reciprocal crosses in all possible combinations between the yellow-green (YG) wild line and two body color mutations — viridian-green (VG) and grayish-white (GW) — of the spiny bollworm,Earias insulana (Boisd.), indicated that these mutations were not sex-linked or controlled cytoplasmically. The YG phenotype was dominant over both body color mutations. A genetic model involving two genes with recessive epistasis is proposed for the inheritance of body color.

     

四纹豆象及其近缘种基于COI基因的分子检测技术研究

四纹豆象是口岸检疫中经常截获的种类,本文以四纹豆象及其近缘种为研究对象,测定分析了COI基因516 bp碱基序列。序列分析结果表明:保守位点为353个,变异位点为163个,简约信息位点为134个,自裔位点为29个。基于Kimura 2-parameter模型分析遗传距离,结果显示:种内遗传距离介于0.001~0.013之间,平均遗传距离为0.008,种间遗传距离介于0.114~0.193,平均遗传距离为0.161。采用邻接法构建的COI基因序列系统发育树显示,同一物种聚为同一小支,且分支自展值均为100%。结果表明应用COI基因片段对四纹豆象及其近缘种进行分子鉴定具有可行性。     

7‐(4,6‐Dimethoxypyrimidinyl)oxy‐ and ‐thiophthalides as novel herbicides: Part 1. CGA 279 233: a new grass‐killer for rice

A series of novel types of 7‐(4,6‐dimethoxypyrimidin‐2‐yl)oxy ‐ and ‐thio‐3‐methyl‐1 (3H)‐isobenzofuranones were discovered at Dr R Maag AG. From the thio‐isobenzofuranyl series, CGA 279 233—BSI‐proposed common name pyriftalid—was chosen for further development as a grass herbicide for use in rice. General synthetic approaches to these new phthalic acid‐derived compounds are given, with emphasis on the synthesis of pyriftalid and its physico‐chemical behaviour. © 2001 Society of Chemical Industry     

Lesion development factors following inoculation ofSclerotinia sclerotiorum mycelium to eggplant,tomato and French bean

The inoculation of different isolates ofSclerotinia sclerotiorum (Lib.) de at various host sites showed that infection severity differed between sites on the same host, but not between isolates. We suggest that these differences are due to variations in relative humidity between the ambient conditions within the plant canopy rather than to different susceptibilities to infection of the plant organs.     

Cultivation legacies in soils after rehabilitation seeding in the Great Basin,USA

Integration of knowledge regarding impacts of historical cultivation on soils for restoration planning is limited even though these legacies can affect land productivity and future land uses for decades. Old fields are often actively transformed through restoration, afforestation, or rehabilitation seeding. Rehabilitation seeding with the introduced perennial grass crested wheatgrass (Agropyron cristatum) was employed on approximately 2 million hectares in the western United States, including old fields in the Great Basin desert region. Seeding continues to be the primary treatment in restoration today, yet a minimal amount is known regarding how the underlying cultivation legacies affect these soils over the long term. We studied sites where rehabilitation seedings overlapped old fields and adjacent noncultivated land to compare soil properties including soil texture, pH, soil organic carbon (SOC), nitrogen (N), and C:N ratios. Because these sites were identical in all aspects except former cultivation, our approach allowed us to test the hypothesis that cultivation legacies can be detected in the soil today and explore which soil properties most strongly reflect cultivation legacies using discriminant and principal components analyses. Discriminant analysis separated soils between the two land-use conditions with 95% confidence at all four sites. Of the six soil properties, SOC, N, and C:N ratios were most important for distinguishing the cultivation legacies at three sites, whereas soil pH was most important in one site. These results show that soils remain altered in these formerly cultivated sites even after being reseeded, suggesting that future productivity and management will also be affected.     

Biodegradation of the Organophosphate Insecticide Coumaphos in Highly Contaminated Soils and in Liquid Wastes

Approximately 400000 litres of cattle dip wastes containing approximately 1500 mg litre⁻¹ of the organophosphate insecticide coumaphos are generated yearly along the Mexican border from a USDA program designed to control disease-carrying cattle ticks. Use of unlined evaporation pits for the disposal of these wastes has resulted in highly contaminated soils underlying these sites. Previous work has shown that microbial consortia present in selected dip wastes can be induced to mineralize coumaphos. Our results demonstrate that similar microbial consortia are present in coumaphos-contaminated soils from eight waste sites and that these organisms are capable of mineralizing cou-maphos in these soils using soil slurries to less than 1 mg litre⁻¹ in 7–10 days at 28°C. In addition, our results show that these consortia are able to colonize pea gravel in trickling gravel filters and can be used in these filters to metabolize coumaphos from dip wastes to less than 0·1 mg litre⁻¹ in 7–10 days at 28°C. These simple systems offer potential low cost means to detoxify coumaphos-containing wastes and to bioremediate soils contaminated with this organophosphate compound.     

Effect of diclobutrazol on the growth and sterol and photosynthetic pigment content of winter wheat

The effect of the fungicide, diclobutrazol, on the germination, growth, chloroplast pigment and sterol content of winter wheat seedlings has been studied. At 250 μEm it retards their germination and growth, producing smaller, darker green and apparently healthy young plants. This is largely due to the 2S,3S–enantiomeric component. The increased greenness is not due to a direct effect on chloroplast pigments. It inhibits sterol 14—demethylation, causing an increase in the content of 4α,14α–dimethyl sterols, and also increases the proportion of campesterol, a 24—methyl sterol, relative to that of the 24—ethyl sterols, stigmasterol and sitosterol. Both the 2R,3R– and 2S,3S–enantiomers appear to be able to cause these changes in sterol content.     

Biochemical aspects of the fungitoxic and growth regulatory action of fenarimol and other pyrimidin-5-ylmethanols

The C-14 demethylation of the sterols, dependent on cytochrome P-450, and the C-22(23) desaturation of sterols are reactions in the ergosterol biosynthesis pathway that are regarded as primary target sites in the toxicity of fungicides of the pyrimidin-5-ylmethanol type. Currently, there is no evidence for target sites in other pathways of comparable sensitivity, although the failure of added ergosterol to reverse the fungitoxicity suggests the existence of such sites. The mitochondrial respiratory systems in Ustilago maydis and Aspergillus nidulans are insensitive to this type of fungicide and are not regarded as primary targets of fungitoxicity in these organisms. Appreciable evidence indicates that the primary targets in higher plant growth regulation are reactions, dependent on cytochrome P-450, that assist in the conversion of kaurene to kaurenoic acid in the gibberellin (GA) biosynthesis pathway. Growth retardation by high concentrations of pyrimidin-5-ylmethanols, which is not reversable by GA, apparently involves action at sites outside the GA biosynthesis pathway. The data derived from various studies of the mechanisms of fungitoxicity and growth regulation suggest that any undetected primary targets of the pyrimidin-5-ylmethanols are likely to be haem enzymes, similar to the cytochrome P-450 involved in sterol C-14 demethylation.     

乌鲁木齐市米东区农田土壤镉污染调查与分析

2010年5月在乌鲁木齐市米东区对农田土壤进行了采样,采样点共67个,采用石墨炉原子吸收光谱仪对土壤中重金属Cd进行了分析。结果表明:米东区农田土壤Cd含量在0.25～1.03mg·kg-1之间,平均值为0.57mg·kg-1。根据单因子评价法,Pi≤0.7的采样点有15个,0.7﹤Pi≤1.0的采样点有21个,1.0相似文献   

The increasing importance of herbicides in worldwide crop production

Herbicide use is increasingly being adopted around the world. Many developing countries (India, China, Bangladesh) are facing shortages of workers to hand weed fields as millions of people move from rural to urban areas. In these countries, herbicides are far cheaper and more readily available than labor for hand weeding. History shows that in industrializing countries in the past, including the United States, Germany, Japan and South Korea, the same phenomenon has occurred—as workers have left agriculture, herbicides have been adopted. It is inevitable that herbicide use will increase in sub‐Saharan Africa, not only because millions of people are leaving rural areas, creating shortages of hand weeders, but also because of the need to increase crop yields. Hand weeding has never been a very efficient method of weed control—often performed too late and not frequently enough. Uncontrolled weeds have been a major cause of low crop yields in sub‐Saharan Africa for a long time. In many parts of the world, herbicides are being increasingly used to replace tillage in order to improve environmental conditions. In comparison with tillage, herbicide use reduces erosion, fuel use, greenhouse gas emissions and nutrient run‐off and conserves water. © 2013 Society of Chemical Industry     

Measures aimed at controlling the invasion of Simulium damnosum Theobald s.l. (Diptera: Simuliidae) into the Onchocerciasis Control Programme Area. III. Searches in the Upper Niger Basin of Guinea for additional sources of flies invading south‐eastern Mali

Abstract

Very large breeding sites of the onchocerciasis vector, Simulium sirbanum were discovered along the Rivers Niger, Mafou, Kouya, Niandan and Milo in the Upper Niger Basin of Guinea. Flies reared from these breeding sites and caught biting man nearby were found to be in the same size range as those collected in the south‐eastern Mali invasion zone of the Onchocerciasis Control Programme Area. The periodicity of the Mali invasion appeared to be related to the hydrological conditions in the Upper Niger Basin during the early monsoon. During this period, rising water levels greatly increase vector breeding in the principal rapids of the Niger and its tributaries which lie upwind and to the south‐west of the invasion sites in south‐eastern Mali. The Mali invasion ceases towards the height of the rainy season when many of these rapids are flooded. It was concluded that the very large breeding sites associated with the principal rapids in the Upper Niger Basin were the main sources of the S. sirbanum invading south‐eastern Mali.     

Interactions of picrodendrins and related terpenoids with ionotropic GABA receptors of mammals and insects

Different structural features govern the interaction of picrodendrins and related terpenoids with rat and with housefly GABA receptors. This supports previous studies which suggest that there are significant differences between the structures of the binding sites in these two receptors.     

Why have no new herbicide modes of action appeared in recent years?

Herbicides with new modes of action are badly needed to manage the evolution of resistance of weeds to existing herbicides. Yet no major new mode of action has been introduced to the market place for about 20 years. There are probably several reasons for this. New potential products may have remained dormant owing to concerns that glyphosate-resistant (GR) crops have reduced the market for a new herbicide. The capture of a large fraction of the herbicide market by glyphosate with GR crops led to significantly diminished herbicide discovery efforts. Some of the reduced herbicide discovery research was also due to company consolidations and the availability of more generic herbicides. Another problem might be that the best herbicide molecular target sites may have already been discovered. However, target sites that are not utilized, for which there are inhibitors that are highly effective at killing plants, suggests that this is not true. Results of modern methods of target site discovery (e.g. gene knockout methods) are mostly not public, but there is no evidence of good herbicides with new target sites coming from these approaches. In summary, there are several reasons for a long dry period for new herbicide target sites; however, the relative magnitude of each is unclear. The economic stimulus to the herbicide industry caused by the evolution of herbicide-resistant weeds, especially GR weeds, may result in one or more new modes of action becoming available in the not too distant future.     

Phosphonate—hydrogen exchange in aqueous solutions of 2H and 3H-labelled phosphonic acid

Phosphonic acid (phosphorous acid), H — PO(OH)₂, the active breakdown product in plant tissues of the systemic anti-oomycete fungicide fosetyl-aluminium was investigated in order to assay the stability of the labelled compound. There is a strong and fast isotopic exchange in unbuffered aqueous solutions of ²H — PO(OH)₂, and therefore ³H — PO(OH)₂, so that Fenn and Coffey's experiments must be reinterpreted because these authors used a stock solution of pure labelled phosphonic acid. However, it is possible to use this last compound for biological experiments under the following conditions: (1) Keeping the dry sodium salt ³H — PO(ONa)₂. 5H₂O in small flasks (100 mg, 37 MBq each) in a vacuum desiccator for individual use without fractionation; (2) using the compound at neutral or slightly acidic pH.