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21.
Production of Monoclonal Antibodies against Apple Proliferation Phytoplasma and their Use in Serological Detection 总被引：2，自引：0，他引：2
Nazia Loi Paolo Ermacora Luigi Carraro Ruggero Osler Tseh An Chen 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(1):81-86
Two monoclonal antibodies were obtained against the apple proliferation phytoplasma that provide easy, rapid, specific and sensitive serological detection. They reacted specifically by using ELISA and immunofluorescence techniques with apple proliferation-infected periwinkles and apple trees from different regions in northern Italy and Slovenia, but not with several other phytoplasma isolates. We did not observe any monoclonal antibody reaction even using phytoplasmas belonging to the same phylogenetic group such as European stone fruit yellows and pear decline. Two serological techniques, immunofluorescence and ELISA, were compared with DAPI staining and PCR. From July until leaf fall ELISA was as sensitive as PCR but was more rapid and convenient than PCR; immunofluorescence was useful for specific detection of apple proliferation phytoplasma on roots throughout the year. Serological techniques could be conveniently applied in the roots, stems and leaves of apple trees depending on specific phenological stages of the plants. 相似文献
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Summary Callus induction, callus growth and organogenetic processes were investigated in hypocotyl and stem cultures of four species of Amaranthus each of which comprised several varieties. Callus formation occurred in almost all the varieties in 100% of explants. The combinations of naphtaleneacetic acid plus benzylaminopurine or 2,4-dichlorophenoxyacetic acid plus Kinetin were very effective in causing callus formation; the results for callus growth in presence of the same growth regulator combinations revealed in some cases significant differences among the varieties.As far organogenesis-based on a few varieties-only A. caudatus and A. hypochondriacus responded well forming shoots from callus when cultured in presence of indoleacetic acid plus Kinetin and/or indoleacetic acid plus benzylaminopurine. Root regeneration was also observed in several varieties. Complete plantlets were obtained from rooted shoots.The results are discussed in relation to hormonal effect and the genotype importance. 相似文献
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Aidan M. Keith René van der Wal Graham H.R. Osler David F.R.P. Burslem 《Soil biology & biochemistry》2006,38(12):3421-3430
To determine whether successional changes in plant communities may influence belowground community structure, we quantified nematode abundance, trophic structure and diversity along two separate chronosequences from heather moorland to birch woodland in the Scottish uplands. Tree invasion markedly altered plant community composition, and hence litter inputs, both directly, and indirectly through changes in understorey species. In turn, these changes in detrital inputs were reflected in consistent changes in nematode community structure. Nematode abundance increased from moorland to birch woodland, with moorland soils being dominated by a few taxa, notably root-hair and fungal feeders, compared to the more diverse composition of the birch woodland soils. Trophic structure was altered through an increase in the abundance of bacterial feeding relative to fungal-feeding nematodes, and an increase in the abundance of predatory nematodes. The increase in predators during the succession from moorland to woodland was associated with an increase in soil pH, highlighting that not only changes in the plant community, but also changes in soil properties associated with tree invasion may influence soil nematodes. Nematode diversity increased from moorland to birch woodland, with nematode richness being positively related to both plant species richness and soil pH. These results suggest that trees may control soil community structure through the manipulation of resources and the soil physico-chemical environment, promoting greater nematode diversity and trophic complexity. 相似文献
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Brzin J. Ermacora P. Osler R. Loi Nazia Ravnikar Maja Petrovič Nataša 《植物病害和植物保护杂志》2003,110(5):476-483
Journal of Plant Diseases and Protection - Apple proliferation (AP), caused by a phytoplasma belonging to AP group, is an important vector-borne and graft-transmissible disease of apple trees in... 相似文献
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ABSTRACT Protocols have been developed using 20- to 24-mer oligodeoxynucleotides, originally designed as polymerase chain reaction primers, as hybridization probes for the nonradioactive detection of Italian clover phyllody (ICPh) phytoplasma in plant (Chrysanthemum carinatum) and leafhopper (Euscelidius variegatus) tissue. In situ hybridization of paraffin-embedded tissue sections was carried out using oligodeoxynucleotides 5' end-labeled with either Cy5 fluorochrome, biotin, or digoxigenin. The Cy5-labeled oligonucleotide probes that hybridized to phytoplasmas present in plant tissue were visualized by confocal microscopy. The biotin- and digoxigeninlabeled probes were detected in both plant and insect tissue using a chromogenic alkaline phosphatase-nitro blue tetrazolium chloride/5-bromo-4-chloro-3-indolyl-phosphate reaction. An enhancement of a signal was observed in plant tissue when a tyramide signal-amplification procedure was incorporated into the biotin or digoxigenin detection systems. The results obtained using these techniques with the ICPh phytoplasma system showed that they can provide a rapid means of confirming vector status in insects. Due to the potential ability of short, labeled, oligonucleotide probes to specifically distinguish between different phytoplasmas present in multiple infections, this technique should provide a powerful new tool for epidemiological and vector ecology studies. 相似文献
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Limited evidence for short-term succession of microarthropods during early phases of surface litter decomposition 总被引：1，自引：0，他引：1
Succession of microarthropods during the decomposition of organic matter is an important concept in soil biology. However, few studies have tested whether the pattern of microarthropod colonisation during decomposition is independent of season. We investigated the pattern of colonisation and dominance of microarthropods on decomposing organic matter placed at two different times. Litterbags containing canola leaf or stem material were placed on the soil surface of a Western Australian agricultural field in July and September 1999. They were collected weekly to fortnightly until November. A final set of bags was collected in May 2000. Mass loss and nutrient contents (C, N, Ca, K, P and S) were measured at each sample time. Microarthropods were sorted to order and the mites to species level. Nematode abundance was determined at each sample time. Mass loss of the leaf and stem material was similar between the two placement times (33% and 15% ash-free dry mass lost over 33 days from leaf and stem material, respectively), although the dynamics of nutrient loss for some elements was different between the two placements. However, over the dry summer, material placed in September continued to lose nutrients whilst there was little additional loss from the material placed in July. A similar pattern of dominance of microarthropod and mite species was found on the leaf and stem material placed in July with the succession of dominant animals more rapid on the stem material. Nematode abundance appeared to increase as populations of microarthropods declined over time. Populations of microarthropods on the material placed in the September samples never achieved similar levels of abundance to that of the July samples, and the dominant fauna groups were dissimilar to those in the July samples for the same degree of decomposition. Our data indicate that the early phase of surface litter decomposition is not a successional process in terms of the microarthropod community irrespective of season and, that abiotic factors are more likely to be determining nutrient loss from organic matter within particular seasons. 相似文献
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OBJECTIVE: To validate intakes of protein, folic acid, retinol and n-3 fatty acids estimated from a food-frequency questionnaire in week 25 of pregnancy (FFQ-25). DESIGN: Validation was done against a 7-day weighed food diary (FD) and biomarkers of the nutrients in gestation week 32-38. SUBJECTS AND SETTING: The FFQ-25 to be validated was used in the Danish National Birth Cohort comprising 101 042 pregnant Danish women, of whom 88 participated in the present validation study. RESULTS: Estimated intakes of protein, retinol and folic acid did not differ significantly between the two dietary methods, but intake of n-3 fatty acids was one third larger when estimated from the FFQ-25. The intakes estimated from the two dietary methods were all significantly correlated, ranging from 0.20 for retinol intake to 0.57 for folic acid intake. Sensitivities of being correctly classified into low and high quintiles were between 0.22 and 0.77, and specificities were between 0.62 and 0.89. Urinary protein content did not correlate significantly with protein estimated from the FFQ (r = 0.17, P > 0.05), but did with intake estimated from the FD (r = 0.56, P < 0.0001). Erythrocyte folate correlated significantly with the estimated total intake from the FFQ (r = 0.55, P < 0.0001) and the FD (r = 0.52, P < 0.0001). No correlations with plasma retinol were found. Erythrocyte eicosapentaenoic acid (C20:5n-3) correlated significantly with n-3 fatty acids intake estimated from both the FFQ-25 (r = 0.37, P < 0.001) and the FD (r = 0.62, P < 0.0001). CONCLUSION: The FFQ-25 gives reasonable valid estimates of protein, retinol and folic acid intakes, but seems to overestimate intake of n-3 fatty acids. 相似文献