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| 2. |
- Amein, Tahsein, et al.
(författare)
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Evaluation of non-chemical seed treatment methods for control of Alternaria brassicicola on cabbage seeds
- 2011
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Ingår i: Journal of Plant Diseases and Protection. - 1861-3829 .- 1861-3837. ; 118:6, s. 214-221
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Tidskriftsartikel (refereegranskat)abstract
- Due to the lack of foliar fungicide use, the organic production of Brassica seeds free of Alternaria spp. is difficult. Therefore, effective seed treatments certified for use in organic farming are needed to eradicate or at least effectively reduce the seed-borne inoculum. We here report results of greenhouse and field experiments in which non-chemical seed treatments were tested for control of A. brassicicola on cabbage seeds naturally infested with the pathogen. In greenhouse experiments, significant improvements were obtained by seed treatment with some commercialised and experimental microbial biocontrol agents, an emulsion of thyme oil in water (0.1%) and by the tested physical seed treatments methods (i.e. hot water, aerated steam and electron seed treatment). Resistance inducers tended to increase the percentage of healthy plants, but the effects were statistically not significant. Generally the combination of physical treatments with the effective agents did not result in improved performance. Positive effects on crop establishment and yield by the same treatments were also observed in field tests. Overall the results indicate that several options for non-chemical control of A. brassicicola on Brassica seeds exist that are comparable in efficacy to the chemical standard Aatiram (active ingredient thiram) used in this study.
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| 3. |
- Huyghe, Jeroen R., et al.
(författare)
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Genome-wide SNP analysis reveals no gain in power for association studies of common variants in the Finnish Saami
- 2010
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 18:5, s. 569-574
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Tidskriftsartikel (refereegranskat)abstract
- The Saami from Fennoscandia are believed to represent an ancient, genetically isolated population with no evidence of population expansion. Theoretical work has indicated that under this demographic scenario, extensive linkage disequilibrium (LD) is generated by genetic drift. Therefore, it has been suggested that the Saami would be particularly suited for genetic association studies, offering a substantial power advantage and allowing more economic study designs. However, no study has yet assessed this claim. As part of a GWAS for a complex trait, we evaluated the relative power for association studies of common variants in the Finnish Saami. LD patterns in the Saami were very similar to those in the non-African HapMap reference panels. Haplotype diversity was reduced and, on average, levels of LD were higher in the Saami as compared with those in the HapMap panels. However, using a 'hidden' SNP approach we show that this does not translate into a power gain in association studies. Contrary to earlier claims, we show that for a given set of common SNPs, genomic coverage attained in the Saami is similar to that in the non-African HapMap panels. Nevertheless, the reduced haplotype diversity could potentially facilitate gene identification, especially if multiple rare variants play a role in disease etiology. Our results further indicate that the HapMap is a useful resource for genetic studies in the Saami.
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| 4. |
- Koch, Eckhard, et al.
(författare)
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Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds
- 2010
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Ingår i: European journal of plant pathology. - : Springer Science and Business Media LLC. - 0929-1873 .- 1573-8469. ; 127:1, s. 99-112
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Tidskriftsartikel (refereegranskat)abstract
- The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems.
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| 5. |
- Van Laer, Lut, et al.
(författare)
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A genome-wide association study for age-related hearing impairment in the Saami
- 2010
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Ingår i: European Journal of Human Genetics. - : BMJ Publishing Group Ltd. - 1018-4813 .- 1476-5438. ; 18:6, s. 685-693
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed at contributing to the elucidation of the genetic basis of age-related hearing impairment (ARHI), a common multifactorial disease with an important genetic contribution as demonstrated by heritability studies. We conducted a genome-wide association study (GWAS) in the Finnish Saami, a small, ancient, genetically isolated population without evidence of demographic expansion. The choice of this study population was motivated by its anticipated higher extent of LD, potentially offering a substantial power advantage for association mapping. DNA samples and audiometric measurements were collected from 352 Finnish Saami individuals, aged between 50 and 75 years. To reduce the burden of multiple testing, we applied principal component (PC) analysis to the multivariate audiometric phenotype. The first three PCs captured 80% of the variation in hearing thresholds, while maintaining biologically important audiometric features. All subjects were genotyped with the Affymetrix 100 K chip. To account for multiple levels of relatedness among subjects, as well as for population stratification, association testing was performed using a mixed model. We summarised the top-ranking association signals for the three traits under study. The top-ranked SNP, rs457717 (P-value 3.55 x 10(-7)), was associated with PC3 and was localised in an intron of the IQ motif-containing GTPase-activating-like protein (IQGAP2). Intriguingly, the SNP rs161927 (P-value 0.000149), seventh-ranked for PC1, was positioned immediately downstream from the metabotropic glutamate receptor-7 gene (GRM7). As a previous GWAS of a European and Finnish sample set already suggested a role for GRM7 in ARHI, this study provides further evidence for the involvement of this gene.
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