Home About us Contact
|
Home About us Contact | ||
|
|
||
Field Resistance (field + resistance)
Selected AbstractsTHE APPRENDI-BLAKELY CASES: SENTENCING REFORM COUNTER REVOLUTION?CRIMINOLOGY AND PUBLIC POLICY, Issue 3 2007RICHARD S. FRASE Recent Supreme Court decisions have extended jury trial rights and beyond-reasonable-doubt proof standards to certain sentence-enhancement facts. The first two cases, Apprendi v. New Jersey and Ring v. Arizona, were narrow in scope and relatively uncontroversial. But Blakely v. Washington marked a substantial expansion of the rationale and scope of Apprendi, and threatened to invalidate entire sentencing reform systems, both legally-binding guidelines of the type at issue in Blakely and it's sequel, Booker v. United States, and statutory determinate sentence systems like the one invalidated in Cunningham v. California. Each of these decisions has potential effects not only on sentencing severity and disparity in the cases controlled by that decision, but also on prosecutorial, legislative, and sentencing commission measures designed to comply with the decision, avoid it, and/or mitigate its impact. Field resistance and avoidance measures are likely to be stronger in jurisdictions where the existing sentencing system enjoyed broad support; in such jurisdictions, resistance may be particularly strong to the more controversial Blakely ruling. Impact assessments must therefore carefully distinguish the separate impacts of Apprendi and Blakely in each jurisdiction being studied, and the extent of support for the existing sentencing system. Such assessments should also examine pre-existing trends and other independent sources of change; leadership by sentencing commissions or other officials in crafting responsive measures; structural and other features of the sentencing system which render compliance more or less difficult; and second-stage effects, on sentencing, prosecutorial, or sentencing policy decisions, that reflect the prior compliance, avoidance, and mitigation measures adopted in that jurisdiction. The greatest long-term effects may be on prosecutorial, legislative, and commission decisions, rather than on sentencing outcomes. [source] Assessment of the resistance of potato cultivars to Synchytrium endobioticum (Schilb.) Per. in PolandEPPO BULLETIN, Issue 2 2008J. Przetakiewicz In Poland the Plant Breeding and Acclimatization Institute is responsible for officially assessing the resistance to Synchytrium endobioticum of domestic potato breeding lines and cultivars from other countries. Cultivation of potato cultivars in Poland requires confirmation of resistance to potato wart disease. The official assessment uses the modified Glynne-Lemmerzahl method (laboratory tests) and pot tests. The full cycle of assessment of resistance to wart disease requires 52 seed potatoes per variety/breeding line. Forty two tubers are used in laboratory tests. To complete the laboratory tests the next 10 tubers are grown in pot tests (in soil with winter sporangia) during the vegetation season. The final results for domestic breeding lines of potato are available after 3 years of investigation. For cultivars from other countries the authorization of resistance to S. endobioticum takes approximately one year. The Polish breeders (breeding lines) or the breeder's representative (cultivars from other countries) receive the certificate only for lines/cultivars with laboratory and field resistance to S. endobioticum. [source] Impact of fungal drug transporters on fungicide sensitivity, multidrug resistance and virulence,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2006Maarten A de Waard Abstract Drug transporters are membrane proteins that provide protection for organisms against natural toxic products and fungicides. In plant pathogens, drug transporters function in baseline sensitivity to fungicides, multidrug resistance (MDR) and virulence on host plants. This paper describes drug transporters of the filamentous fungi Aspergillus nidulans (Eidam) Winter, Botrytis cinerea Pers and Mycosphaerella graminicola (Fückel) Schroter that function in fungicide sensitivity and resistance. The fungi possess ATP-binding cassette (ABC) drug transporters that mediate MDR to fungicides in laboratory mutants. Similar mutants are not pronounced in field resistance to most classes of fungicide but may play a role in resistance to azoles. MDR may also explain historical cases of resistance to aromatic hydrocarbon fungicides and dodine. In clinical situations, MDR development in Candida albicans (Robin) Berkhout mediated by ABC transporters in patients suffering from candidiasis is common after prolonged treatment with azoles. Factors that can explain this striking difference between agricultural and clinical situations are discussed. Attention is also paid to the risk of MDR development in plant pathogens in the future. Finally, the paper describes the impact of fungal drug transporters on drug discovery. Copyright © 2006 Society of Chemical Industry [source] Laboratory studies to assess the risk of development of resistance to zoxamidePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2001David H Young Abstract Laboratory studies were conducted to evaluate the risk of developing field resistance to zoxamide, a new Oomycete fungicide which acts on microtubules. Zoxamide, metalaxyl and dimethomorph were compared with respect to the ease with which fungicide-resistant mutants could be isolated and their level of resistance. Attempts to generate mutants of Phytophthora capsici and P infestans with resistance to zoxamide by mycelial adaptation on fungicide-amended medium were unsuccessful. Similarly, changes in sensitivity to zoxamide were small (resistance factors ,2.2) in mutants of P capsici isolated by chemical mutagenesis of zoospore cysts. In parallel experiments with metalaxyl, highly resistant mutants were obtained using both adaptation (P capsici or P infestans) and chemical mutagenesis (P capsici). For dimethomorph, chemical mutagenesis (P capsici) yielded moderately resistant mutants (maximum resistance factor,=,20.9), and adaptation (P capsici or P infestans) did not induce resistance. It is proposed that failure to isolate mutants resistant to zoxamide results from the diploid nature of Oomycete fungi and the likelihood that target-site mutations would produce a recessive phenotype. Our studies suggest that the risk of a highly resistant pathogen population developing rapidly in the field is much lower for zoxamide than for metalaxyl. However, as with any site-specific fungicide, appropriate precautions against resistance development should be taken. © 2001 Society of Chemical Industry [source] Development of early-flowering Kabuli chickpea with compound and simple leavesPLANT BREEDING, Issue 2 2007D. J. Bonfil Abstract Terminal drought is a major constraint to chickpea (Cicer arietinum L.) production. Autumn sowing and early flowering have been suggested as ways to benefit from the winter rains in short rainy seasons under dryland cropping. High-yielding, late-flowering, simple-leafed (slv/slv) chickpea cultivars with good field resistance to Ascochyta blight have been bred recently. Changing plant architecture, by altering leaf shape, may affect agronomic performance. As no information is available on the effect of leaf shape on phenology and seed yield, this study was aimed at: (i) introducing the simple leaf trait into an early-flowering chickpea background; (ii) comparing the grain yield of the two leaf types in early vs. late flowering backgrounds and (iii) producing breeding lines combining early flowering, large seeds and Ascochyta tolerance with both leaf types. Hybrid progeny were studied from the cross of ,Sanford' (slv/slv) and ICC7344, (compound, SLV/SLV). Four early-podding, F8 breeding lines were selected with either simple or compound leaves. In three different field experiments under dryland conditions (334,379 mm), they yielded ca. 1.4 t/ha as compared with 1.0 t/ha in the standard Israeli ,Yarden' on one site, but no significant differences in yield were obtained in the other two experiments. [source] Late blight resistance in a diploid full-sib potato familyPLANT BREEDING, Issue 4 2004S. Costanzo Abstract Late blight, caused by Phytophthora infestans (Mont.) de Bary, is the most destructive disease of potato worldwide. As this pathogen can rapidly overcome major race-specific resistance genes, identifying the basis for enhanced quantitative resistance has become a crucial element for implementing advanced breeding strategies. A population of 230 full-sib progeny derived from a cross between two diploid hybrid Solanum phureja × S. stenotomum clones was evaluated for foliage resistance against late blight in replicated trials at multiple locations in Pennsylvania between 1999 and 2002. In field experiments, plants were evaluated visually for per cent defoliation, and area under the disease progress curve (AUDPC) was determined. The two parents and three control cultivars (,Atlantic', ,Kennebec' and ,Katahdin') were included in all trials. In all three experiments, the presence of a significant number of clones exhibiting transgressive segregation were observed. There were significant differences among environments as well as among clones, and the clone × environment interaction was also significant. Stability analysis revealed that 37 clones made a significant contribution to the overall environment × clone interaction. Broad-sense heritability for resistance, measured as AUDPC, was estimated as 0.67. The overall results indicate the presence in this potato family of a high level of field resistance against late blight. This segregating diploid family appears to be a good candidate for quantitative trait loci mapping to identify and characterize the genetic components of partial late blight resistance. [source] A green fluorescent protein-based screening method for identification of resistance in anthurium to systemic infection by Xanthomonas axonopodis pv. dieffenbachiaePLANT PATHOLOGY, Issue 5 2007W. Elibox Resistance of cultivars of Anthurium andraeanum to systemic infection by Xanthomonas axonopodis pv. dieffenbachiae, the causal organism of bacterial blight disease of anthurium, was investigated using a bioengineered bacterial strain containing p519ngfp plasmid. Successful infection establishment in anthurium was found to be cultivar and inoculum density dependent, but independent of plant age. Injection of cut petioles (stage-2 leaf) with 100 µL inoculum (109 CFU mL,1) resulted in 100% infection establishment in susceptible cultivars on a repeatable basis, and differentiated between various levels of observed field resistance. Time to death (weeks) and proportion of dead plants best differentiated between levels of resistance and cultivars were placed in four groups based on these criteria. The susceptible group (32 cultivars) rapidly declined within 6,12 weeks of inoculation (WAI) and resulted in 100% plant death; the moderately resistant group (10 cultivars) declined within 12 WAI, but resulted in less than 100% plant death; the resistant category had less than 100% plant death with a slow decline taking over 20 weeks; and the highly resistant category (15 cultivars) showed 0% infection. The correlation coefficient between green fluorescent protein (GFP)-fluorescence and eventual death of plants was 0·90, indicating that the final death of individual plants can be reasonably well predicted based on GFP-fluorescence data at 5 WAI. Hence GFP data at 5 WAI can be used for early detection of latently infected plants and may assist screening for resistance in segregating populations of anthurium. [source] Mutants in wheat showing multipathogen resistance to biotrophic fungal pathogensPLANT PATHOLOGY, Issue 4 2006L. A. Boyd Five fast-neutron-derived mutants were isolated from the wheat line Hobbit ,sib' that show enhanced field resistance towards Puccinia striiformis f.sp. tritici, the causal agent of yellow rust. Subsequent testing showed the yellow rust resistance phenotypes to differ between mutants, to be expressed at different growth stages and, in some cases, to show an isolate interaction. Three mutants, I3-48, I3-49 and I3-54, exhibited an enhanced yellow rust resistance phenotype from the third seedling leaf onwards, while mutants I3-27 and I3-30 did not show an altered yellow rust phenotype until later growth stages. Additional resistance for brown rust (causal agent Puccinia triticina) was identified in mutants I3-27, I3-30, I3-48 and I3-49, and for powdery mildew caused by Blumeria graminis f.sp. tritici in mutants I3-27, I3-30, I3-48 and I3-54, although in some cases the resistance was isolate-specific. [source] Expression of resistance to Leptosphaeria maculans in Brassica napus double haploid lines in France and Australia is influenced by locationANNALS OF APPLIED BIOLOGY, Issue 2 2008R. Delourme Abstract Blackleg, caused by Leptosphaeria maculans, is a major disease of oilseed rape (Brassica napus), worldwide, including Australia and France. The aims of these studies were first, to determine if higher levels of resistance to L. maculans could be generated in double haploid (DH) lines derived from spring-type B. napus cv. Grouse, which has a good level of field resistance to blackleg; and second, to determine whether the resistance to blackleg disease of individual DH lines responds differentially to different L. maculans field populations within and between the two countries. DH lines were extracted from cv. Grouse and tested in field experiments carried out in both France and Australia against natural L. maculans populations. Extracting and screening DH lines were an effective means to select individual lines with greatly improved expression of resistance to blackleg crown canker disease in comparison with the original parental population. However, relative disease resistance rankings for DH lines were not always consistent between sites. The higher level of resistance in France was shown to be because of a high expression level of quantitative resistance in the French growing conditions. Big differences were observed for some DH lines between the 2004 and the 2005 field sites in Australia where the L. maculans populations differed by their virulence on single dominant gene-based resistant lines derived from Brassica rapa ssp. sylvestris. This differential behaviour could not be clearly explained by the specific resistance genes until now identified in these DH lines. This investigation highlights the potential to derive DH lines with superior levels of resistance to L. maculans compared with parental populations. However, in locations with particularly high pathogen diversity, such as in southern Australia, multiyear and multisite evaluations should be performed to screen for the most efficient material in different situations. [source] Effectiveness of resistance genes to the large raspberry aphid, Amphorophora idaei Börner, in different raspberry (Rubus idaeus L.) genotypes and under different environmental conditionsANNALS OF APPLIED BIOLOGY, Issue 2 2000A T JONES Summary The introduction into commerce of raspberry cultivars with major gene resistance to the large raspberry aphid, Amphorophora idaei, an important pest and virus vector on red raspberry in Europe, has been very effective both in decreasing pest numbers and greatly restricting infection with the viruses it transmits. However, biotypes of the aphid able to overcome these genes have developed in the field in recent years. Additionally, in field and laboratory tests, the response to aphid biotypes and recognised aphid strains of certain raspberry cultivars, such as Glen Prosen and Delight, differ markedly despite the fact that they are reputed to contain the same A. idaei -resistance gene, A1. In attempts to understand the reasons for this difference in response, analysis was made of the segregation of progeny seedlings from crosses between A. idaei -resistant and -susceptible cultivars to two recognised strains of the aphid. These studies showed that, as expected, cv. Autumn Bliss contained the A. idaei -resistance gene, A10, and cvs Delight and Glen Prosen each contained the A. idaei -resistance gene, A1. When progeny seedlings were assayed in a heated glasshouse as young plants and in an unheated Tygan house as 1 m tall plants, the segregation ratios for resistance and susceptibility to A. idaei were largely unchanged. However, when the resistance of individual progeny plants was assessed, c. 37% of the putative gene A1 -containing progeny and 9,23% of the putative gene A10 -containing progeny, behaved differently in these two environments. Experiments involving an A. idaei -resistant and -susceptible parent cultivar showed that shading plants increased their susceptibility to A. idaei colonisation. Whilst this shading effect has implications for experimentally detecting A. idaei -resistant progeny in segregating raspberry seedlings, it does not explain the difference in field resistance to A. idaei of cvs Delight and Glen Prosen. Such differences in the field seem best explained by the presence in these cultivars of ,minor' genes for A. idaei resistance and/or susceptibility that influences the effectiveness of gene A1. [source] | ||||||||||