bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity of mesotrione on resistant weeds in maize
Authors: Sutton Peter , Richards Claire , Buren Larry , Glasgow Les 
Published: August 2002

AbstractMesotrione is a new callistemone herbicide that inhibits the HPPD enzyme (p‐hydroxyphenylpyruvate dioxygenase) and introduces a new naturally selective tool into weed‐management programmes for use in maize. Mesotrione provides control of the major broad‐leaved weeds, and it can be used in integrated weed‐management programmes depending on the grower's preferred weed‐control strategy. At post‐emergence rates of 150 g AI ha−1 or less, mesotrione provides naturally selective control of key species that may show triazine resistance (TR), eg Chenopodium album L, Amaranthus species, Solanum nigrum L, as well as species of weed that show resistance to acetolactase synthase (ALS) inhibitors eg Xanthium strumarium L, Amaranthus spp and Sonchus spp. The data presented show that resistant and susceptible biotypes of these species with resistance to triazine herbicides, such as atrazine, simazine, terbutylazine and metribuzin, or ALS‐inhibitor herbicides, such as imazethepyr, remain susceptible to mesotrione. These results confirm that there is no cross‐resistance in biotypes with target site resistance to triazine or ALS‐inhibiting herbicides. It is important that herbicide choice and rotation becomes an integral part of planning weed management, so as to minimise the risks of crop losses from weed competition, build‐up of weed seed in the soil and the further development of weed resistance across a range of herbicide modes of action.© 2002 Society of Chemical Industry
Cross‐resistance to imidazolinone herbicides in chlorsulfuron‐resistant Raphanus raphanistrum
Authors: Hashem Abul , Dhammu Harmohinder S 
Published: August 2002

AbstractRaphanus raphanistrum L has evolved widespread resistance to sulfonylureas in the Western Australia (WA) wheat belt. With the introduction of imidazolinone‐tolerant (IT) wheat (Tritcum aestivum L) and IT canola (Brassica napus L) in the WA wheat belt, it is important to understand the status of cross‐resistance in this weed to sulfonylurea and imidazolinone (Imi) herbicides. A study was conducted to examine cross‐resistance between chlorsulfuron and Imi herbicides (a mixture of imazapic and imazapyr) in 46 R raphanistrum populations collected from across the WA wheat belt. Plants were treated with herbicides and assessed for phytotoxicity under glasshouse conditions. Of the 46 R raphanistrum populations, 32 were resistant to chlorsulfuron and four were resistant to imazapic + imazapyr. Of the 70% chlorsulfuron‐resistant populations, 13% showed cross‐resistance to imazapic + imazapyr. However, the cross‐resistant populations treated with imazapic + imazapyr showed a lower resistance level than the chlorsulfuron‐treated populations. These results suggest that weed populations with such cross‐resistance will not be controlled effectively by Imi herbicides. Although the resistance levels of the cross‐resistant populations to Imi herbicides were low, the cross‐resistance levels of R raphanistrum should be determined before growing IT crops, particularly IT canola.© 2002 Society of Chemical Industry
Quinoxyfen—resistance management and sensitivity monitoring in wheat: 1995–2000
Authors: Bernhard Uli , Leader Andrew , Longhurst Chris , Felsenstein Friedrich G 
Published: August 2002

AbstractWheat powdery mildew, Blumeria ( = Erysiphe) graminis DC f sp tritici Marschal is one of the most important foliar diseases of cereals in Europe, and has shown a high potential for adaptability in sensitivity towards modern fungicides during the last 20 years. Quinoxyfen is a surface‐mobile fungicide from a new chemical class that has been commercially used for the control of B graminis in Europe since 1997. When the compound was launched, a Resistance Management Strategy was implemented which included: no seed treatments, no autumn use, a specified window of application and recommendations for appropriate tank‐mixing. To assess the success of this Management Strategy, a European‐wide resistance monitoring programme was carried out between 1995 and 2000 using spore trap sampling, and a whole plant assay. The mean EC50 values found by year were 0.060 mg litre−1 in 1995, 0.052 mg litre−1 in 1996, 0.071 ml litre−1 in 1997, 0.039 mg litre−1 in 1998, 0.039 mg litre−1 in 1999 and 0.063 mg litre−1 in 2000. No new sensitivity classes were found. The slight shift to lower sensitivity in 1998 and 1999 was correlated with similar shifts in three wild‐type isolates, and was ascribed to experimental variation. The monitoring programme will continue to assess the long‐term impact of the management recommendations on the resistance status of quinoxyfen.© 2002 Society of Chemical Industry
Population changes in Phytophthora infestans in Taiwan associated with the appearance of resistance to metalaxyl
Authors: Deahl Kenneth L , Cooke Louise R , Black Lowell L , Wang Tien Chen , Perez Frances M , Moravec Brian C , Quinn Michele , Jones Richard W 
Published: August 2002

AbstractIn recent years, late blight, caused by Phytophthora infestans (Mont) De Bary, has increased in severity in many parts of the world, and this has been associated with migrations which have introduced new, arguably more aggressive, populations of the pathogen. In Taiwan, late blight has been endemic on outdoor tomato crops grown in the highlands since the early 1900s, but recent epidemics have been more damaging. To ascertain the present status of the Taiwanese population of P infestans, 139 isolates of the pathogen collected and maintained by the Asian Vegetable Research and Development Center (AVRDC) were characterized using mating type, metalaxyl sensitivity, allozyme genotype, mitochondrial haplotype and RFLP fingerprinting. Up to 1997, all isolates were found to belong to the old clonal lineage of P infestans (US‐1 and variants), but in isolates from 1998 a new genotype appeared, and by 2000 this had apparently completely displaced the old population. This new genotype was an A1 mating type and has the dilocus allozyme genotype 100/100/111, 100/100 for the loci coding for glucose‐6‐phosphate isomerase and peptidase, respectively. These characters, together with RG57 fingerprinting, indicated that these isolates belonged to the US‐11 clonal lineage, a minority (11%) being a previously unreported variant of US‐11. Whereas metalaxyl‐resistant isolates were not detected in the old population, 96% of the new genotypes proved resistant, with the remainder being intermediate in sensitivity. It may be inferred from this sudden, marked change in the characteristics of the Taiwanese P infestans that a new population of the pathogen was introduced around 1997–98 and that this may well have already been metalaxyl‐resistant when it arrived, although a role for in situ selection cannot be excluded.© 2002 Society of Chemical Industry
Establishment of the baseline sensitivity and monitoring response of Papaver rhoeas populations to florasulam
Authors: Paterson E A , Shenton Z L , Straszewski A E 
Published: August 2002

AbstractIn accordance with the EPPO guideline for the efficacy evaluation of plant protection products, resistance risk analysis PP 1/213(1), a method was established to determine the baseline sensitivity of key weed species to florasulam, a new triazolopyrimidine sulfonanilide herbicide for post‐emergence control of dicotyledonous weeds in cereals. The aim of the baseline monitoring project was to understand the natural variation in response to florasulam of diverse populations of Papaver rhoeas at the time of product launch. The method entailed seed collection from representative agricultural areas throughout Europe. The seed was subjected to glasshouse tests where dose‐response studies were conducted and ED80 values generated. This enabled a sensitivity index to be calculated for each country, giving an indication of the variation in P rhoeas response to florasulam in the populations tested.© 2002 Society of Chemical Industry
What impact will EPPO's new resistance risk assessment guideline have on selection pressure in the European Union?
Authors: Leonard Paul K , Dutton Robert 
Published: August 2002

AbstractThis paper examines practical and regulatory implications, including both costs and benefits, resulting from implementation of EPPO's new resistance risk analysis guideline. Crop‐protection companies operating in Europe are preparing risk analyses and management strategies, and are monitoring for resistance. However, this is a complex and expensive process involving technical, commercial and regulatory functions. The actual cost of filling these data gaps is consequently greater than many would have anticipated. The agrochemical industry has a vested interest in managing resistance and is committed to maintaining the essential contribution of crop‐protection products to sustainable agriculture. However, with increasing regulatory costs, it is important that regulatory authorities concentrate requirements for resistance risk analyses, management strategies and monitoring where these are most needed. Should these requirements be applied indiscriminately, crop‐protection companies will have to consider whether or not it is economically justifiable to make these investments, or whether to remove less profitable uses from product labels. In such situations, minor crops stand to be disproportionately effected. One year after publication, it is too early to measure the guideline's impact on selection pressure. It is already clear that the guideline represents an unprecedented step forward in the regulation and harmonisation of resistance management. There are, however, valid arguments against regulation of resistance management. One of the most important criticisms that is levelled against the latter approach is that, with the best motivation and with appropriate use restrictions on labels, these actions alone do not solve the problem. It is critical that all stakeholders in the crop protection process are made aware of the importance of resistance management and of complying with prescribed strategies.© 2002 Society of Chemical Industry
Analysis of insecticide‐resistant Myzus persicae (Sulzer) populations collected in Italian peach orchards
Authors: Mazzoni Emanuele , Cravedi Piero 
Published: August 2002

AbstractSeveral populations of the green peach aphid, Myzus persicae (Sulzer), were collected in the most important Italian peach‐growing areas. In these populations, collected as primary colonies or as secondary ones, total esterase content and acetylcholinesterase sensitivity towards pirimicarb was assessed using biochemical assays. Most of the individuals analysed generally exhibited an elevated esterase content, and in some cases acetylcholinesterase insensitivity. The implications of resistance levels and distribution on M persicae control strategies are discussed. © 2002 Society of Chemical Industry
Mechanisms of resistance to fungicides in field strains of Botrytis cinerea
Authors: Leroux Pierre , Fritz René , Debieu Danièle , Albertini Catherine , Lanen Catherine , Bach Jocelyne , Gredt Michel , Chapeland Florence 
Published: August 2002

AbstractField strains of Botrytis cinerea Pers ex Fr, the causal agent of grey mould diseases, were collected from French vineyards between 1993 and 2000. Several phenotypes have been characterized according to the inhibitory effects of fungicides towards germ‐tube elongation and mycelial growth. Two types of benzimidazole‐resistant strains (Ben R1 and Ben R2) could be detected; negative cross‐resistance to phenylcarbamates (eg diethofencarb) was only found in Ben R1. Benzimidazole resistance was related to point mutations at codon 198 (Ben R1) or 200 (Ben R2) of the β‐tubulin gene. Most dicarboximide‐resistant strains were also weakly resistant to aromatic hydrocarbon fungicides (eg dicloran) but remained sensitive to phenylpyrroles (eg fludioxonil). These resistant field strains (Imi R1) contained a single base pair mutation at position 365 in a two‐component histidine kinase gene, probably involved in the fungal osmoregulation. Three anilinopyrimidine‐resistant phenotypes have been identified. In the most resistant one (Ani R1), resistance was restricted to anilinopyrimidines, but no differences were observed in the amino‐acid sequences of cystathionine β‐lyase (the potential target site of these fungicides) from Ani R1 or wild‐type strains. In the two other phenotypes (Ani R2 and Ani R3), resistance extended to various other groups of fungicide, including dicarboximides, phenylpyrroles and sterol biosynthesis inhibitors. This multi‐drug resistance was probably determined by over‐production of ATP‐binding cassette transporters. The hydroxyanilide fenhexamid is a novel botryticide whose primary target site is the 3‐keto reductase involved in sterol C‐4 demethylations. Apart from the multi‐drug‐resistant strain Ani R3, three other fenhexamid‐resistant phenotypes have been recognized. For two of them (Hyd R1 and Hyd R2) fenhexamid‐resistance seemed to result from P450‐mediated detoxification. Reduced sensitivity of the target site could be the putative resistance mechanism operating in the third resistant phenotype (Hyd R3). Increased sensitivity to inhibitors of sterol 14 α‐demethylase recorded in Hyd R1 strains was related to two amino‐acid changes at positions 15 and 105 of this enzyme.© 2002 Society of Chemical Industry
Insecticide resistance in field populations of Frankliniella occidentalis (Pergande) in Murcia (south‐east Spain)
Authors: Espinosa Pedro J , Bielza Pablo , Contreras Josefina , Lacasa Alfredo 
Published: August 2002

AbstractThirty‐nine field populations of Frankliniella occidentalis (Pergande) were collected from different crops (sweet pepper, tomato, lettuce, artichoke, melon, cucumber, carnation, broad bean, peach and plum) in Murcia (south‐east Spain). All populations were reared separately in the laboratory to obtain enough individuals for bioassays. Female thrips were bioassayed, using a standard topical application method, against methiocarb, methamidophos, acrinathrin, endosulfan, deltamethrin and formetanate. Methiocarb was the only insecticide that showed a high efficacy against F occidentalis at field dose rates. Acrinathrin and methamidophos were moderately effective, while endosulfan and deltamethrin were ineffective. Only moderate levels of resistance (Resistance Ratios at LC50 of 10–30) were detected for the selective insecticides methiocarb, formetanate and acrinathrin used against F occidentalis in crops where these insecticides are used intensively. This generalized and low level of resistance to these insecticides, coupled with a lack of efficacy for the three broad‐spectrum insectides, was observed even in intensively managed vegetable crops. Implementation of IPM strategies in Murcia has contributed to more successful insecticide anti‐resistance management.© 2002 Society of Chemical Industry
Field and laboratory selection of Frankliniella occidentalis (Pergande) for resistance to insecticides
Authors: Espinosa Pedro J , Bielza Pablo , Contreras Josefina , Lacasa Alfredo 
Published: August 2002

AbstractResponse of western flower thrips, Frankliniella occidentalis (Pergande), to selection for resistance to insecticides commonly used to control this pest in Murcia (south‐east Spain) was studied under field and laboratory conditions. In the field, plots within sweet pepper crops in commercial and experimental greenhouses were treated under different selection strategies: insecticide rotation versus formetanate reiteration, formetanate reiteration versus acrinathrin reiteration, and formetanate reiteration versus methiocarb reiteration. Thrips populations were sampled monthly and bioassayed against methiocarb, methamidophos, acrinathrin, endosulfan, deltamethrin and formetanate. In the laboratory, F occidentalis strains were selected against each insecticide for several generations. To evaluate cross‐resistance, each selected strain was bioassayed with the other insecticides. Frankliniella occidentalis populations showed a rapid development of acrinathrin resistance, reaching high levels in field and laboratory conditions. Formetanate and methiocarb resistance were also observed, although development was slower and at moderate levels. Cross‐resistances between acrinathrin/deltamethrin and acrinathrin/formetanate were detected under field and laboratory conditions. Formetanate/methiocarb cross‐resistance was suspected in laboratory selections, but not in field assays. Simultaneous moderate resistance levels to the three specific insecticides against thrips (formetanate, methiocarb and acrinathrin) were shown in laboratory selection strains, indicating a general mechanism of resistance, probably metabolic.© 2002 Society of Chemical Industry
Spatial organization and conformational peculiarities of the callatostatin family of neuropeptides
Authors: Alieva I. N. , Velieva L. I. , Aliev D. I. , Godjaev N. M. 
Published: August 2002

AbstractThe structures and conformational peculiarities of five members of the callatostatin family of neuropeptides, i.e. Leu‐ and Met‐callatostatins, ranging in size from 8 to 16 amino acid residues have been investigated by a theoretical conformational analysis method. A comparative analysis of the conformational flexibilities of Met‐callatostatin with those of the hydroxylated analogues, [Hyp2]‐ and [Hyp3]‐ Met‐callatostatin has been carried out. Helically packed C‐terminal pentapeptide in the structure of all investigated Leu‐callatostatins are shown to be possible. The reason for the great number low‐energy conformers for the callatostatin N‐terminus is discussed. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Mass spectrometric and chemical stability of the Asp‐Pro bond in herpes simplex virus epitope peptides compared with X‐Pro bonds of related sequences
Authors: Skribanek Zsolt , Mező Gábor , Mák Marianna , Hudecz Ferenc 
Published: August 2002

AbstractThe mass spectrometric analysis of the immunodominant epitope region (273–284) of herpes simplex virus type 1 (HSV‐1) glycoprotein D (gD) showed a favoured fission at the Asp‐Pro peptide bond. The fast atom bombardment collision induced dissociation (FAB‐CID) study of closely related X‐Pro peptides documented that neither the length nor the amino acid composition of the peptide has a significant influence on this preferential cleavage. At the same time the DP bond proved to be sensitive to acidic conditions in the course of peptide synthesis. These observations prompted us to compare the chemical and mass spectrometric stability of a new set of nonapeptides related to the 273–284 epitope region of gD, i.e. SALLEDPVG and SALLEXPVG peptides, where X = A, K, I, S, F, E or D, respectively. The chemical stability of these peptides during acidic hydrolysis was investigated by electrospray ionization mass spectrometry (ESI‐MS) and the products were identified by ESI‐MS and on‐line high performance liquid chromatography—mass spectrometry (HPLC‐MS). The mass spectrometric fragmentation and bond stability of the untreated peptide samples were also studied using ESI‐MS and liquid secondary ion mass spectrometry (LSIMS). Both the chemical hydrolysis and the mass spectrometric fragmentation showed that the Asp‐Pro bond could easily be cleaved, while the KP bond proved to be stable under both circumstances. On the other hand, the XP bond (X = A, I, S, F or E) fragmented easily under the mass spectrometric conditions, but was not sensitive to the acidolysis. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Synthesis and biological properties of the seven alanine‐modified analogues of the marine cyclopeptide hymenamide C
Authors: Napolitano Assunta , Bruno Ines , Rovero Paolo , Lucas Rut , Payà Peris Miguel , Gomez‐Paloma Luigi , Riccio Raffaele 
Published: August 2002

AbstractThe synthesis and biological activity of the marine cyclopeptide hymenamide C(1), showing an inhibitory effect on human neutrophil elastase degranulation release, were recently described. Based on this result, it was decided to undertake a systematic structure–activity relationship study of this cyclopeptide, based on the Ala‐scan technique, in order to obtain useful information for the rational design of additional analogues. The synthesis and characterization of the seven Ala modified analogues are reported and their biological and pharmacological properties are described. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Antimicrobial activity of short arginine‐ and tryptophan‐rich peptides
Authors: Strøm Morten B. , Rekdal Øystein , Svendsen John S. 
Published: August 2002

AbstractHighly antimicrobial active arginine‐ and tryptophan‐rich peptides were synthesized ranging in size from 11 to five amino acid residues in order to elucidate the main structural requirement for such short antimicrobial peptides. The amino acid sequences of the peptides were based on previous studies of longer bovine and murine lactoferricin derivatives. Most of the peptides showed strong inhibitory action against the Gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa, and the Gram‐positive bacterium Staphylococcus aureus. For the most active derivatives, the minimal inhibitory concentration values observed for the Gram‐negative bacteria were 5 µg/ml (3.5 µM), whereas it was 2.5 µg/ml (1.5 µM) for the Gram‐positive bacterium. It was essential for the antimicrobial activity that the peptides contained a minimum of three tryptophan and three arginine residues, and carried a free N‐terminal amino group and an amidated C‐terminal end. Furthermore, a minimum sequence size of seven amino acid residues was required for a high antimicrobial activity against Pseudomonas aeruginosa. The insertion of additional arginine and tryptophan residues into the peptides resulted only in small variations in the antimicrobial activity, whereas replacement of a tryptophan residue with tyrosine in the hepta‐ and hexapeptides resulted in reduced antimicrobial activity, especially against the Gram‐negative bacteria. The peptides were non‐haemolytic, making them highly potent as prospective antibiotic agents. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Antiproliferative action of valorphin in cell cultures
Authors: Blishchenko Elena , Sazonova Olga , Surovoy Andrei , Khaidukov Sergei , Sheikine Yury , Sokolov Dmitry , Freidlin Irina , Philippova Marina , Vass Arpad , Karelin Andrei , Ivanov Vadim 
Published: August 2002

AbstractThe antiproliferative effects of the haemoglobin β‐chain fragment (33–39) (valorphin or VV‐haemorphin‐5) were studied in a panel of tumour cell lines and normal cells of different origin, using various methods of activity determination (trypan blue inclusion test, sulphorhodamine B staining, MTT staining, flow cytometry and clonogenic test). Valorphin suppressed the proliferation of tumour cells by 25%–95%, depending on the cell line. The maximal valorphin activity was detected in transformed cells of fibroblastic (L929) and epithelial (MCF‐7) origin, transformed haematopoietic cells (K562, HL‐60) being less sensitive. In normal cells, valorphin activity was several fold lower (10%–15%). A study of the dynamics of cell proliferation in L929 cells using a visual cell count and flow cytometry showed that valorphin induced reversible and relatively short (24 h) S‐phase arrest of cell proliferation, accompanied by a reversible increase of cell size. The proliferation delay was followed by a comparatively long period of reversible resistance of the cells to the peptide (96 h) when the cells are dividing at normal rate. The same dynamics were demonstrated for A549, MCF‐7 and primary murine breast carcinoma cells. On the basis of the data obtained, a pattern of regulation of cell growth by valorphin is suggested. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.