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| 2. |
- Berlin, Anna, et al.
(författare)
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Scientific evidence for sustainable plant disease protection strategies for the main arable crops in Sweden. A systematic map protocol
- 2018
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Ingår i: Environmental Evidence. - : Springer Science and Business Media LLC. - 2047-2382. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Efficient and sustainable plant protection is of great economic and ecological significance for global crop production. A number of challenges, e.g. climate change, population growth and global trade, put increasing demands on future crop production and crop protection. This necessitates an increase in crop productivity with less environmental impact while maintaining good food quality and food security. To meet these challenges, it is essential that the recommendations provided to growers are efficient and correct, which can only be ensured by evidence-based recommendations based on outcomes from scientific studies.Methods and output: The aim of these systematic maps is to compile scientific evidence for different plant disease protection strategies for the main arable crops grown in Sweden. Six major crops (wheat, barley, oat, potato, sugar beet and oilseed rape) have been selected based on the area under production, the annual production, the economic importance, and the amount of pesticide used against diseases in these crops in Sweden. All methods to manage diseases will be considered, including cropping system, pesticide application, biological control methods, as well as combinations of methods and integrated pest management. These systematic maps will only deal with field studies of relevance for agricultural practices in Sweden, although we expect that the results will be applicable for northern Europe as a whole. The main outcome to be used will be productivity measured as yield per area. Plant health and pathogen reduction will be included as a proxy for potential increase in crop quality and yield. This will provide a systematic overview of the plant disease protection measures that have been reported in the scientific literature. The study will result in one searchable database per crop that may be used as a catalogue of evidence for researchers and stakeholders, especially authorities and advisory organizations. The systematic maps will aid in the identification of areas that need further research and guide funding agencies and policymakers when deciding where research resources should be allocated. It will also help to select topics for future systematic reviews and meta-studies within the field of plant protection.
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| 3. |
- Bödeker, Inga, et al.
(författare)
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Mycorrhizal and saprotrophic fungal guilds compete for the same organic substrates but affect decomposition differently
- 2016
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Ingår i: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 30, s. 1967-1978
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Tidskriftsartikel (refereegranskat)abstract
- 1. Communities of litter saprotrophic and root-associated fungi are vertically separated within boreal forest soil profiles. It is unclear whether this depth partitioning is maintained exclusively by substrate-mediated niche partitioning (i.e. distinct fundamental niches), or by competition for space and resources (i.e. distinct realized niches). Improved understanding of the mechanisms driving spatial partitioning of these fungal guilds is critical, as they modulate carbon and nutrient cycling in different ways.2. Under field settings, we tested the effects of substrate quality and the local fungal species pool at various depths in determining the potential of saprotrophic and mycorrhizal fungi to colonize and exploit organic matter. Natural substrates of three qualities-fresh or partly decomposed litter or humus -were incubated in the corresponding organic layers of a boreal forest soil profile in a fully factorial design. After one and two growing seasons, fungal community composition in the substrates was determined by 454-pyrosequencing and decomposition was analyzed.3. Fungal community development during the course of the experiment was determined to similar degrees by vertical location of the substrates (24% of explained variation) and by substrate quality (20%), indicating that interference competition is a strong additional driver of the substrate-dependent depth partitioning of fungal guilds in the system. During the first growing season, litter substrates decomposed slower when colonized by root-associated communities than when colonized by communities of litter saprotrophs, whereas humus was only slightly decomposed by both fungal guilds. During the second season, certain basidiomycetes from both guilds were particularly efficient in localizing and exploiting their native organic substrates although displaced in the vertical profile. This validates that fungal community composition, rather than microclimatic factors, were responsible for observed depth-related differences in decomposer activities during the first season.4. In conclusion, our results suggest that saprotrophic and root-associated fungal guilds have overlapping fundamental niches with respect to colonization of substrates of different qualities, and that their substrate-dependent depth partitioning in soils of ectomycorrhiza-dominated ecosystems is reinforced by interference competition. Through competitive interactions, mycorrhizal fungi can thus indirectly regulate litter decomposition rates by restraining activities of more efficient litter saprotrophs.
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| 4. |
- Capador-Barreto, Hernán Dario, et al.
(författare)
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Development of microsatellite markers for Thekopsora areolata, the causal agent of cherry spruce rust
- 2018
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Ingår i: Forest Pathology. - : Wiley. - 1437-4781 .- 1439-0329. ; 48
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Tidskriftsartikel (refereegranskat)abstract
- Cherry spruce rust is a fungal disease of Norway spruce cones caused by Thekopsora areolata and responsible for significant losses in seed production in Sweden and Finland. Here, we report the first set of nine microsatellites, which will allow an effective genetic fingerprinting of T.areolata. The markers were isolated using the FIASCO method and were characterized using DNA from 49 single aecia sampled from spruce cones in three different seed orchards in Sweden. Eight of the nine markers were shown to be polymorphic among the aecia. The markers were unlinked and are therefore suitable for future population genetic studies.
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| 6. |
- Chen, Zhi‑Qiang, et al.
(författare)
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Early selection for resistance to Heterobasidion parviporum in Norway spruce is not likely to adversely affect growth and wood quality traits in late-age performance
- 2018
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Ingår i: European Journal of Forest Research. - : Springer Science and Business Media LLC. - 1612-4669 .- 1612-4677. ; 137:4, s. 517-525
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Tidskriftsartikel (refereegranskat)abstract
- Infections with Heterobasidion parviporum devalue the Norway spruce timber as the decayed wood does not meet the necessary quality requirements for sawing. To evaluate the incorporation of disease resistance in the Norway spruce breeding strategy, an inoculation experiment with H. parviporum on 2-year-old progenies of 466 open-pollinated families was conducted under greenhouse (nursery) conditions. Lesion length in the phloem (LL), fungal growth in sapwood (FG) and growth (D) were measured on an average of 10 seedlings for each family. The genetic variation and genetic correlations between both LL, FG and growth in the nursery trial and wood quality traits measured previously from 21-year old trees in two progeny trials, including solid-wood quality traits (wood density, and modulus of elasticity) and fiber properties traits (radial fiber width, tangential fiber width, fiber wall thickness, fiber coarseness, microfibril angle and fiber length). For both LL and FG, large coefficients of phenotypic variation (> 26%) and genetic variation (> 46%) were detected. Heritabilities of LL and FG were 0.33 and 0.42, respectively. We found no significant correlations between wood quality traits and growth in the field progeny trials with neither LL nor FG in the nursery trial. Our data suggest that the genetic gains may reach 41 and 52% from mass selection by LL and FG, respectively. Early selection for resistance to H. parviporum based on assessments of fungal spread in the sapwood in nursery material, FG, will not adversely affect growth and wood quality traits in late-age performance.
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| 7. |
- Clergeot, Pierre-Henri, et al.
(författare)
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Estimating the Fitness Effect of Deleterious Mutations During the Two Phases of the Life Cycle : A New Method Applied to the Root-Rot Fungus Heterobasidion parviporum
- 2019
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Ingår i: Genetics. - : Oxford University Press (OUP). - 0016-6731 .- 1943-2631. ; 211:3, s. 963-976
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Tidskriftsartikel (refereegranskat)abstract
- Many eukaryote species, including taxa such as fungi or algae, have a lifecycle with substantial haploid and diploid phases. A recent theoretical model predicts that such haploid-diploid lifecycles are stable over long evolutionary time scales when segregating deleterious mutations have stronger effects in homozygous diploids than in haploids and when they are partially recessive in heterozygous diploids. The model predicts that effective dominance-a measure that accounts for these two effects-should be close to 0.5 in these species. It also predicts that diploids should have higher fitness than haploids on average. However, an appropriate statistical framework to conjointly investigate these predictions is currently lacking. In this study, we derive a new quantitative genetic model to test these predictions using fitness data of two haploid parents and their diploid offspring, and genome-wide genetic distance between haploid parents. We apply this model to the root-rot basidiomycete fungus Heterobasidion parviporum-a species where the heterokaryotic (equivalent to the diploid) phase is longer than the homokaryotic (haploid) phase. We measured two fitness-related traits (mycelium growth rate and the ability to degrade wood) in both homokaryons and heterokaryons, and we used whole-genome sequencing to estimate nuclear genetic distance between parents. Possibly due to a lack of power, we did not find that deleterious mutations were recessive or more deleterious when expressed during the heterokaryotic phase. Using this model to compare effective dominance among haploid-diploid species where the relative importance of the two phases varies should help better understand the evolution of haploid-diploid life cycles.
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| 8. |
- Fang, Jun, et al.
(författare)
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Functional characterization of a multi-cancer risk locus on chr5p15.33 reveals regulation of TERT by ZNF148
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Genome wide association studies (GWAS) have mapped multiple independent cancer susceptibility loci to chr5p15.33. Here, we show that fine-mapping of pancreatic and testicular cancer GWAS within one of these loci (Region 2 in CLPTM1L) focuses the signal to nine highly correlated SNPs. Of these, rs36115365-C associated with increased pancreatic and testicular but decreased lung cancer and melanoma risk, and exhibited preferred protein-binding and enhanced regulatory activity. Transcriptional gene silencing of this regulatory element repressed TERT expression in an allele-specific manner. Proteomic analysis identifies allele-preferred binding of Zinc finger protein 148 (ZNF148) to rs36115365-C, further supported by binding of purified recombinant ZNF148. Knockdown of ZNF148 results in reduced TERT expression, telomerase activity and telomere length. Our results indicate that the association with chr5p15.33-Region 2 may be explained by rs36115365, a variant influencing TERT expression via ZNF148 in a manner consistent with elevated TERT in carriers of the C allele.
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| 9. |
- Hu, Yang, et al.
(författare)
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Characterization of a Heterobasidion irregulare endo-rhamnogalacturonase that mediate growth on pectin
- 2018
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Ingår i: Journal of Phytopathology. - : Wiley. - 0931-1785 .- 1439-0434. ; 166, s. 34-43
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Tidskriftsartikel (refereegranskat)abstract
- Heterobasidion irregulare is one of five Heterobasidion annosum sensu lato (s.l.) species, which are destructive pathogens in boreal and temperate forests of the northern hemisphere that causes root and butt rot in conifer. A gene encoding endo-rhamnogalacturonase (HIRHG), which belongs to the glycoside hydrolase family 28 (GH28), was found in a quantitative trait loci (QTL) region for virulence in Heterobasidion. In this study, we showed that HIRHG is highly upregulated during necrotrophic infection of Norway spruce compared with growth in liquid culture and that the HIRHG encoded protein is produced during fungal growth on complex carbon sources. Phylogenetic analysis of endo-rhamnogalacturonases revealed that rhamnogalacturonase genes have been lost in most of the biotrophic and hemibiotrophic plant pathogens investigated but were common in necrotrophic pathogens and saprophytic fungi. Heterologous expression of the HIRHG gene in the hemibiotrophic fungus Magnaporthe oryzae increased its capacity to grow on pectin; however, the transformed M.oryzae isolates showed significant less infection of rice leaves compared to the wild type.
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| 10. |
- Liu, Bing, et al.
(författare)
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Biochemical studies of two lytic polysaccharide monooxygenases from the white-rot fungus Heterobasidion irregulare and their roles in lignocellulose degradation
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Lytic polysaccharide monooxygenases (LPMO) are important redox enzymes produced by microorganisms for the degradation of recalcitrant natural polysaccharides. Heterobasidion irregulare is a white-rot phytopathogenic fungus that causes wood decay in conifers. The genome of this fungus encodes 10 putative Auxiliary Activity family 9 (AA9) LPMOs. We describe the first biochemical characterization of H. irregulare LPMOs through heterologous expression of two CBM-containing LPMOs from this fungus (HiLPMO9H, HiLPMO9I) in Pichia pastoris. The oxidization preferences and substrate specificities of these two enzymes were determined. The two LPMOs were shown to cleave different carbohydrate components of plant cell walls. HiLPMO9H was active on cellulose and oxidized the substrate at the C1 carbon of the pyranose ring at beta-1,4-glycosidic linkages, whereas HiLPMO9I cleaved cellulose with strict oxidization at the C4 carbon of glucose unit at internal bonds, and also showed activity against glucomannan. We propose that the two LPMOs play different roles in the plant-cell-wall degrading system of H. irregulare for degradation of softwood and that the lignocellulose degradation mediated by this white-rot fungus may require collective efforts from multi-types of LPMOs.
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