PCR-based detection of sterol demethylation inhibitor-resistant strains of Penicillium digitatum     

Hamamoto H  Hasegawa K  Nakaune R  Lee YJ  Akutsu K  Hibi T 《Pest management science》2001,57(9):839-843

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Laboratory and field evaluation of the pathogenicity of entomopathogenic nematodes to the red palm weevil, Rhynchophorus ferrugineus (Oliv.) (Col.: Curculionidae)     

M. S. T. Abbas  M. M. E. Saleh  A. M. Akil 《Anzeiger für Sch?dlingskunde》2001,54(4):167-168

Ten Egyptian and imported entomopathogenic nematodes were evaluated for their pathogenicity to R. ferrugineus in both the laboratory and the field. In the laboratory, most nematodes were pathogenic to the pest larvae, pupae and adults. Larvae and adults were more susceptible to nematode infection (mostly 100% mortality) than pupae enclosed in their cocoons. In the field however, the highest insect larval mortality was 66.67% and most of nematodes failed in controlling the pest. Such failure could be due to hot weather, the tunnelling behaviour of the pest larvae and the too much sap in the infested sites in the trunks of palm trees.  相似文献   

Identification of novel inhibitors of calling and in vitro [14C]acetate incorporation by pheromone glands of Plodia interpunctella     

Hirashima A  Eiraku T  Watanabe Y  Kuwano E  Taniguchi E  Eto M 《Pest management science》2001,57(8):713-720

Some octopamine agonists were found to suppress in vitro biosynthesis of the calling pheromone of the Indian meal moth, Plodia interpunctella. Isolated pheromone-gland preparations incorporated sodium [14C]acetate at a linear rate for 3 h when incubated with the pheromone biosynthesis activating neuropeptide (PBAN). This incorporation was dependent on the dose of PBAN (up to 0.5 microM). Thin-layer chromatography of a pheromone-gland extract revealed quantitative incorporation of radioactivity into a product exhibiting the same mobility as (Z,E)-9,12-tetradecadienyl acetate, the main component of the calling pheromone of P interpunctella. Twenty-seven octopamine agonists were initially screened using a calling behaviour bioassay of female P interpunctella. Four derivatives with activity in the nanomolar range were identified which were, in order of decreasing pheromonostatic activity: 2-(2,6-diethylphenylimino)thiazolidine > 2-(2,6-diethylphenylimino)oxazolidine > 2-(2,6-dimethylphenylimino)thiazolidine > 2-(2-ethylphenylimino)oxazolidine. These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis. The results of the present study indicate that these derivatives could provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.  相似文献   

Adsorption-desorption behaviour of flufenacet in five different soils of India     

Gajbhiye VT  Gupta S 《Pest management science》2001,57(7):633-639

Adsorption-desorption of the herbicide flufenacet (FOE 5043) has been studied in five soils from different locations in India (Delhi, Ranchi, Nagpur, Kerala and Assam) varying in their physicochemical properties. The organic matter (OM) content varied from 0.072 to 0.864%, clay content from 2.5 to 43.7% and pH from 4.45 to 8.35. The adsorption studies were carried out using a batch equilibration technique. Ten grams of soil were equilibrated with 20 ml of aqueous 0.01 M CaCl2 solution containing different concentrations (0-30 mg litre-1) of flufenacet. After equilibration, an aliquot of supernatant was taken out for analysis. During desorption, the amount withdrawn for analysis was replenished with fresh 0.01 M CaCl2 solution and further equilibrated. Desorption studies were carried out with the 30 mg litre-1 concentration of flufenacet only. The adsorption studies revealed that there was moderate to high adsorption of flufenacet considering the comparatively low organic carbon content in the five test soils. Average Kd values ranged from 0.77 to 4.52 and Freundlich KF values from 0.76 to 4.39. The highest adsorption was observed in Kerala soil (OM 0.786%; clay 25%; pH 4.45) followed by Ranchi, Nagpur and Delhi soils, and the lowest in Assam soil (OM 0.553%; clay 2.5%; pH 6.87). The trend in adsorption could be attributed to the chemical nature of flufenacet and the physicochemical properties of the soil such as pH, OM and clay contents. OM and clay contents were positively correlated whereas pH was negatively correlated. Soils having low pH, high OM and high clay contents showed higher adsorption. Desorption studies revealed that there was a hysteresis effect in all the soils. Hysteresis coefficient values (ratio of n(ad) and n(des)) varied from 0.09 to 0.45. The study implies that, because of its moderate to high adsorption, flufenacet is likely to persist in soil for some time. However, the possibility of its movement by leaching or surface run off is less.  相似文献   

Aggressiveness of Xanthomonas axonopodis pv. glycines isolates to soybean and hypersensitivity responses by other plants     

S. Kaewnum  S. Prathuangwong  T. J. Burr † 《Plant pathology》2005,54(3):409-415

Xanthomonas axonopodis pv. glycines ( Xag ) causes bacterial pustule disease which can significantly reduce the production of soybean. A collection of 26 isolates of Xag from different soybean-production areas of Thailand was shown to differ with regard to aggressiveness on soybean. They also differed in their ability to induce a hypersensitive response (HR) on four cultivars of tobacco and on other plant species including pepper, tomato, cucumber, pea and sesame. Tomato was most sensitive to HR induction by Xag . Isolate KU-P-34017 caused an HR on all the plant species tested. The minimal concentration of KU-P-34017 needed to induce HR on tobacco was approximately 5 × 10⁸ CFU mL⁻¹. A bacterium–plant interaction period of at least 2·5 h was necessary for HR, and different temperatures, relative humidity and light periods did not affect HR development. Inhibitors of eukaryotic metabolism, including cobalt chloride, lanthanum chloride and sodium orthovanadate (completely), and cycloheximide (partially) blocked the HR on tobacco, indicating the association of an active plant response. In contrast, the HR on tomato was inhibited only by cobalt chloride.  相似文献   

PCR-based detection of Xanthomonas campestris pathovars in Brassica seed     

T. Berg  L. Tesoriero  D. L. Hailstones† 《Plant pathology》2005,54(3):416-427

Xanthomonas campestris is a seedborne bacterium that causes black rot of crucifers. Substantial crop losses may result from the rapid spread of the bacteria under favourable conditions, especially those occurring during seedling production. A PCR-based method has been developed for the rapid and sensitive detection of the pathovars of X. campestris that affect crucifers. Primers were designed to specifically amplify a 619 bp fragment of the hrpF gene from X. campestris . Amplification products were not detected from other Xanthomonas species, or from other pathogenic or epiphytic bacteria occurring on these plants. To avoid false-negative results arising from the presence of amplification inhibitors in plant extracts, primers targeting a 360 bp section of the internal transcribed spacer (ITS) region from Brassica spp. were included in a multiplex PCR. The assay readily detected X. campestris pv. campestris infections in diseased plants and from bacterial colonies isolated on growth media, and was more sensitive and specific than traditional plating methods and a commercially available ELISA. A seed-washing protocol was optimized to allow the detection of a single artificially infected seed among 10 000 healthy seeds using the multiplex PCR.  相似文献   

Dioscorea alata, a new host of Sclerotium rolfsii in India     

M. L. Jeeva  V. Hegde  T. Makeshkumar  R. R. Nair  S. Edison 《Plant pathology》2005,54(4):574-574

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Genetic diversity and mixed infections of begomoviruses infecting tomato, pepper and cucurbit crops in Nicaragua   总被引：1，自引：0，他引：1  

M. Ala-Poikela  E. Svensson ‡  A. Rojas  T. Horko  L. Paulin  J. P. T. Valkonen  A. Kvarnheden † 《Plant pathology》2005,54(4):448-459

Begomoviruses were detected in Nicaraguan fields of tomato ( Lycopersicon esculentum ) and adjacently growing plants of pepper ( Capsicum annuum ), chilli pepper ( C . baccatum ), cushaw ( Cucurbita argyrosperma ) and Mexican fireplant ( Euphorbia heterophylla ) using polymerase chain reaction (PCR) and universal begomovirus primers. All tomato and Mexican fireplant plants showing symptoms were infected with begomoviruses, while only 30–46% of the pepper, chilli pepper and cushaw plants showing symptoms tested virus-positive. No begomoviruses were found in potato. The virus species were provisionally identified by sequencing 533 bp of the viral coat protein gene ( AV1 ). Tomato severe leaf curl virus (ToSLCV), Tomato leaf curl Sinaloa virus (ToLCSinV) and Pepper golden mosaic virus (PepGMV) were found to infect both tomato and pepper. A new provisional species designated Tomato leaf curl Las Playitas virus (ToLCLPV) was detected in a tomato plant. Squash yellow mottle virus (SYMoV) and PepGMV were found in cucurbits, the latter for the first time in this host. Euphorbia mosaic virus (EuMV) was detected in Mexican fireplant. Sequencing of a larger number of PCR-amplified clones from selected plants revealed intraspecific viral sequence variability, and also multiple begomovirus infections which could represent up to three species in a single tomato or cushaw plant. Phylogenetic grouping of virus sequences did not correlate with the host of origin.  相似文献   

New severe strains of Melon necrotic spot virus: symptomatology and sequencing     

C. Kubo  E. Nakazono-Nagaoka  K. Hagiwara  H. Kajihara  S. Takeuchi  K. Matsuo  T. U. Ichiki  T. Omura † 《Plant pathology》2005,54(5):615-620

New strains of Melon necrotic spot virus (MNSV), designated MNSV-YS and MNSV-KS, caused much more severe growth retardation on melon plants than MNSV-NH, which was previously reported as the most severe strain of MNSV in Japan. MNSV-YS spread much more quickly than MNSV-NH in infected plants, and induced more severe growth retardation, even though the appearance of necrotic lesions on inoculated cotyledons was much slower. MNSV-KS had properties intermediate between those of the other two strains. The results suggest that faster-spreading strains can multiply more rapidly as a result of lower levels of activity in inducing necrotic lesions in melon plants. The complete sequences of MNSV-YS and MNSV-KS were determined, and an RT–PCR–RFLP method based on these sequences was successfully developed to detect and discriminate between the three strains.  相似文献   

Investigation of Senescence in Canine Fibroblasts     

S. Streit    F. -V. Salomon    T. Stahl 《Anatomia, histologia, embryologia》2005,34(S1):50-51

Introduction and Aims:  Primary and secondary cell cultures of canine dermal fibroblasts were used to test the suitability of several senescence-linked cellular markers to characterize the chronological age of dogs. In further studies these markers will be used to test the hypothesis that senescence-linked changes at the cellular level are representative for the observed inverse relationship of body mass and life expectancy in different dog breeds.
Methods:  In this study standardized skin samples of Beagles were used to analyse the cell morphology and several senescence-linked parameters as Cumulative Population Doubling Level, Highest Population Doubling Level, Culture Doubling Time and Life Span Completed to determine the replicative potential of fibroblasts. The samples were divided by the age of the donors into three groups ('young', 'middle' and 'old').
Results:  There are notable differences between the replicative potential of young and old Beagles at the cellular level. Preliminary results show that in fibroblast cultures obtained from the young group the highest population doubling level is higher and the culture doubling time is shorter then in cultures of the old group. Cultures from the young and middle-aged group cannot be distinguished by the measured parameters. For final results the complete statistical analysis of sampled data has to be carried out.
Conclusions:  Our results demonstrate a relationship between the chronological age of the skin donor and the replicative potential of the dermal fibroblasts. Therefore cellular senescence-linked markers could serve as suitable tools to compare the age of individual dogs of different breeds.  相似文献