摘要:

AbstractMaize kernels were treated with the fungicide triticonazole (RP‐727), belonging to the triazole family. The nuclear DNA content was analyzed in various maize plant organs by using flow cytometry. Two fluorochromes with different DNA binding mechanisms were used for probing nuclear DNA and chromatin structure. Results indicated nuclear alterations with the use of triticonazole and the alterations observed were different in the various tissues analyzed. Active meristematic plant organs, such as root tip, did not show any significant change in nuclear DNA, but chromatin structure was altered with increasing concentrations of fungicide. Stem and mesocotyl showed both DNA and chromatin condensation changes with triticonazole concentration, but the trends observed in these two plant organs were opposite. The magnitude of the alterations was minute in the different plant organs studied. These alterations do not appear to be deleterious for normal plant developmen

ISSN:0031-613X    

DOI:10.1002/ps.2780410402

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe synthesis of several derivatives of a pesticide and an α‐amino acid are described. The process involves three steps, the last one (deprotection of the α‐amino acid group) being the most critical. The resulting products preserved their α‐amino acid group and were globally neutral. They were tested for their effect on the transport of a neutral amino acid, threonine, and two sugars, sucrose and glucose. Two derivatives markedly and specifically inhibited threonine uptake by leaf tissues ofVicia fabaL. and phloem loading. Preliminary experiments suggested that the lysine‐2,4‐D derivative is a competitive inhibitor of threonine uptake. The apparentKi(0.5 mM) was much lower than the apparentKm(3 mm) of the natur

ISSN:0031-613X    

DOI:10.1002/ps.2780410403

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe inhibition of alkaline hydrolysis of organophosphorothioate pesticides such as parathion, parathion‐methyl and fenitrothion by the formation of inclusion complexes with β‐cyclodextrin and its methylated derivatives was investigated. The inclusion complex/pesticide stability relationship with the series of pesticides and β‐cyclodextrins is discussed in connection with the inclusion geometrical parameters, such as those relating to the inclusion orientation and depth of the 4‐nitrophenoxy moiety of the included pesticide. These parameters were estimated from the induced circular dichroism of the inclusion complexes by means of the rotational‐strength anal

ISSN:0031-613X    

DOI:10.1002/ps.2780410404

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA study was conducted to relate the occurrence of accelerated pesticide biodegradation to the susceptibility of the pesticides to growth‐linked degradation or cometabolism. The mineralization of 2,4‐D was initially slow but then became rapid, and a second application was mineralized with no acclimation phase and more rapidly than the first. The numbers of 2,4‐D‐degrading micro‐organisms increased markedly following its first application and then declined, but the population size increased after a second addition. Glyphosate was rapidly and extensively mineralized following the first and second applications to soil, and the abundance of organisms able to degrade it rose after the first addition and remained high before and following the second application. Propham (IPC) mineralization was detected only 15 days after its application but the degradation was rapid thereafter, and the second addition was rapidly and extensively mineralized with no acclimation phase. The population of propham‐degrading micro‐organisms was initially small, but increased markedy 10 days after the initial herbicide addition and was still large at the time of the second application. The rate of carbofuran biodegradation in the test soil was the same following the first and second applications, and the abundance of carbofuran‐metabolizing microorganisms did not change appreciably as a result of soil treatment with the insecticide. Simazine mineralization was slow, although the rate was higher following the second addition; however, the number of simazine‐degrading organisms did not increase appreciably. From 10 to 12% of the14C from radiolabeled 2,4‐D, propham, glyphosate or glucose was usually incorporated into the microbial biomass of soil but 0.82% or less of the14C from simazine or ring‐ or carbonyl‐labeled carbofuran was converted to biomass. It is suggested that pesticides that support microbial growth may be subject to accelerated biodegradation if the population remains large until the pesticide is applied again. Pesticides that do not support growth may not be subject to acc

ISSN:0031-613X    

DOI:10.1002/ps.2780410405

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractNewly synthesized compounds were examined in screening tests with the pea aphid,Acyrthosiphon pisum(Harris) for juvenilizing effects. usign the spray‐residue method. Two derivatives of 2‐(4‐hydroxvbenzyl)eyclohexanone bearing a carbamate or an ether group were found to be the most active inhibitors of development and reproduction. Tests with the hop aphid,Phorodon humuli(Schrank) of insecticide‐susceptible and multi‐resistant biotypes and with the green peach aphid,Myzus persicae(Sulzer) confirmed their biological activity. Cross‐resistance between conventional insecticides and juvenoids was not indicated. The formation of supernumerary larvae, where retention of larval cauda and corresponding larval characters were observed and reproduction was entirely suppressed, was recognized as the critical result of the juvenilizing effect. The production of viable progeny was not affected in those aphids which survived treatment and developed normal adult externa

ISSN:0031-613X    

DOI:10.1002/ps.2780410406

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractExcised shoots from apple trees and cell suspension cultures were used as model systems to study the metabolism of [3,5‐14C]amitrole inMalus domesticaBorkh. Significant differences in the metabolism of the compound applied were observed with excised shoots, cultured cells and whole apple trees. The major metabolite in excised shoots was aminotriazolylalanine which occurred both in the free form and as conjugates. The major metabolite from whole plants. triazolylalanine, was detected in shoots in minor amounts only. In cell suspension cultures, the type of metabolism strongly depended on the concentration of amitrole when initially applied. At 10−3m or lower, mainly aminotriazolylalanine was formed. Depending on the concentration of the active ingredient, this metabolite predominantly occurred in free form or as glycosides. At concentrations above 5 × 10−4M a new metabolite, 3,5‐dihydroxytriazole, was detected which was the only metabolite found at 5 × 10−3M. Significant amounts of nonmetabolized amitrole remained in

ISSN:0031-613X    

DOI:10.1002/ps.2780410407

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA highly selective method for the detection of several pesticides containing a heteroaromatic ring in the molecule (e.g. nicotine, pyrifenox or prochloraz) on thin‐layer chromatographic (TLC) plates is described. The necessary detection condition is the presence in the ring of at least one tertiary nitrogen atom without substitutents on the two adjacent carbon atoms and, in the case of azoles, the protection of a secondary NH group by an alkyl or acyl group. The detection is realized by spraying the developed chromatogram with an acetone solution of 2‐trichloromethylbenzimidazole and subsequently heating at 100‐150°C in a drier. The detection limit is 20 ng to 10 μg depending on the detected compound. Some pesticide formulations may be analyzed using this

ISSN:0031-613X    

DOI:10.1002/ps.2780410408

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractChemical analysis of rodenticide residues in regurgitated owl pellets has been shown to be a sensitive, non‐invasive method for monitoring the potential exposure of Barn Owls to second‐generation rodenticides in their prey. The method, originally developed for flocoumafen, has been extended to two other rodenticides. brodifacoum and difenacoum.The method was validated as part of a toxicity study in which Barn Owls were separately fed 40–130 μg day−1of brodifacoum, difenacoum and flocoumafen in mice over 15 days. Each day an average of 25% of the consumed rodenticide was regurgitated in the

ISSN:0031-613X    

DOI:10.1002/ps.2780410409

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA molecular diagnostic was used to examine the conservation of cyclodiene resistance associated mutations between different strains ofTribolium castaneum(Herbst.). An improved insecticide bioassay for discrimination between resistant genotypes was developed and seven resistant strains were established from five different continents. In order to develop a molecular diagnostic a partial cDNA of the cyclodiene insecticide resistance geneRdl, a γ‐aminobutyric‐acid‐gated chloride‐ion channel, was cloned and sequenced. This cDNA spans exon 7, the region containing the resistance‐associated mutation, and part of exon 8. An ‘allele‐specific’ oligonucleotide primer, carrying the resistance‐associated mutation at its 3′ end, was used in combination with a flanking ‘allele‐independent’ primer in the polymerase chain reaction to selectively amplify a single resistance‐associated mutation from all seven strains collected worldwide. The implications of these findings for the population genetics of insecticide resistance and its management in pest insects

ISSN:0031-613X    

DOI:10.1002/ps.2780410410

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe paper describes a methodology for specifying the deposition of spray droplets on flying insects and insects at rest on a quantitative basis. Processes of deposition by sedimentation and inertial impaction are viewed in terms of a deposition velocity defined byvg=vsax+ Eiuaz, in whichvsis the droplet settling velocity, u the air speed relative to the insect,Eia collection efficiency associated with inertial impaction andax,azsignify horizontal and vertical projections of a representative trapping area. Published data on the deposition of small droplets (diameter<20μm) on mosquitoes show that the trapping efficiency is dominated by inertial impaction and it is assumed that the collection efficiency is specified by Ei= St2/(St + 0.2)2in which St is the Stokes number. Analysis of a second data set regarding the deposition of larger drops on flying locusts shows that the dependence of the observed collection efficiency on droplet size can be explained satisfactorily by this simplified approach. Further, it is demonstrated that a characteristic length which forms an essential component of the Stokes number is matched to the general size of the insect. The paper concludes with an analysis of a further data set concerning the deposition of small drops onto resting tsetse flies; this provides insight into the effective air speed controlling the deposition process

ISSN:0031-613X    

DOI:10.1002/ps.2780410411

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY