Swedish University of Agricultural Sciences

About: Swedish University of Agricultural Sciences is a education organization based out in Uppsala, Sweden. It is known for research contribution in the topics: Population & Soil water. The organization has 13510 authors who have published 35241 publications receiving 1414458 citations. The organization is also known as: Sveriges Lantbruksuniversitet & SLU.

Genetic diversity of eleven European pig breeds

Abstract: A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwabisch-Hallisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall FST = 0.27), and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

The way forward in biochar research: targeting trade‐offs between the potential wins

Abstract: Biochar application to soil is currently widely advocated for a variety of reasons related to sustainability. Typically, soil amelioration with biochar is presented as a multiple-‘win’ strategy, although it is also associated with potential risks such as environmental contamination. The most often claimed benefits of biochar (i.e. the ‘wins’) include (i) carbon sequestration; (ii) soil fertility enhancement; (iii) biofuel/bioenergy production; (iv) pollutant immobilization; and (v) waste disposal. However, the vast majority of studies ignore possible trade-offs between them. For example, there is an obvious trade-off between maximizing biofuel production and maximizing biochar production. Also, relatively little attention has been paid to mechanisms, as opposed to systems impacts, behind observed biochar effects, often leaving open the question as to whether they reflect truly unique properties of biochar as opposed to being simply the short-term consequences of a fertilization or liming effect. Here, we provide an outline for the future of soil biochar research. We first identify possible trade-offs between the potential benefits. Second, to be able to better understand and quantify these trade-offs, we propose guidelines for robust experimental design and selection of appropriate controls that allow both mechanistic and systems assessment of biochar effects and trade-offs between the wins. Third, we offer a conceptual framework to guide future experiments and suggest guidelines for the standardized reporting of biochar experiments to allow effective between-site comparisons to quantify trade-offs. Such a mechanistic and systems framework is required to allow effective comparisons between experiments, across scales and locations, to guide policy and recommendations concerning biochar application to soil.

Conifer root and butt rot caused by Heterobasidion annosum (Fr.) Bref. s.l.

Abstract: SUMMARY The root and butt rot caused by Heterobasidon annosum is one of the most destructive diseases of conifers in the northern temperate regions of the world, particularly in Europe Economic losses attributable to Heterobasidion infection in Europe are estimated at 800 million euros annually The fungus has been classified into three separate European intersterile species P ( H annosum ), S ( H parviporum ) and F ( H abietinum ) based on their main host preferences: pine, spruce and fir, respectively In North America, two intersterile groups are present, P and S/F, but these have not been given scientific names The ecology of the disease spread has been intensively studied but the genetics, biochemistry and molecular aspects of pathogen virulence have been relatively little examined Recent advances in transcript profiling, molecular characterization of pathogenicity factors and establishment of DNA-transformation systems have paved the way for future advances in our understanding of this pathosystem Taxonomy: Heterobasidion annosum (Fr) Bref, H parviporum Niemela & Korhonen and H abietinum Niemela & Korhonen; kingdom Fungi; class Basidiomycotina; order Aphyllophorales; family Bondarzewiaceae; genus Heterobasidion Identification: presence of the fungus fruit bodies, basidiocarps whitish in the margins, upper surface is tan to dark brown, usually irregular shaped, 35 ( − 7) cm thick and up to 40 cm in diameter; pores 5‐19, 7‐22 and 13‐26 mm 2 for the P, F and S groups, respectively Small brownish non-sporulating postules develop on the outside of infected roots Asexual spores (conidiospores) are 38‐66 × 28‐50 µ m in size Mating tests are necessary for identification of intersterility groups Host range: The fungus attacks many coniferous tree species In Europe, particularly trees of the genera Pinus and Juniperus (P), Picea (S), Abies (F) and in North America Pinus (P) and Picea , Tsuga and Abies (S/F) To a lesser extent it causes root rot on some decidous trees ( Betula and Quercus ) Disease symptoms: symptoms (eg exhudation of resin, crown deterioration) due to Heterobasidion root rot in living trees are not particularly characteristic and in most cases cannot be distinguished from those caused by other root pathogens Heterobasidion annosum sl is a white rot fungus Initial growth in wood causes a stain that varies in colour depending on host tree species Incipient decay is normally pale yellow and it develops into a light brown decay to become a white pocket rot with black flecks in its advanced stage Control: silvicultural methods (eg stump removal), chemicals (urea, borates) and biological control agent ( Phlebiopsis gigantea , marketed as PG Suspension® in the UK, PG IBL® in Poland and Rotstop® in Fennoscandia) are commonly used approaches for minimizing the disease spread

Collection of airborne micro-organisms on Nuclepore filters, estimation and analysis--CAMNEA method

Abstract: The total number of airborne micro-organisms collected on Nuclepore filters was determined by acridine orange staining and epifluorescence microscopy. The viable fraction of the total numbers varied significantly when actinomycete and fungal spores from different environments were stored on the filter surface for 1 week, although the microflora composition was not altered. A high correlation between viable and total counts was noted in environments where the airborne flora was dominated by fungal spores, while a low correlation was found for airborne bacteria. Peak values of the total counts registered in some work environments varied between 10(7) and 10(11) micro-organisms/m3. Size analysis showed a dominating fraction of respirable micro-organisms (aerodynamical diameter less than 5 micron). The investigation shows that it is of the utmost importance to combine viable counts with total count enumeration in the study of exposure to micro-organisms in work-related situations.

Changes in feather condition in relation to feather pecking and aggressive behaviour in laying hens

Abstract: The aim of this experiment was to describe and examine the relationship between pecks received by individual birds and the feather and skin damage of those birds at different ages. The effect of group size was also studied. Laying hens were raised in floor pens in group sizes of 15, 30, 60 and 120 birds, each with 4 replicates. Behavioural observations were performed at the ages of 22, 27, 32 and 37 weeks. Detailed feather scoring was carried out at the ages of 18, 23, 28 and 33 weeks. Behavioural observations focused on the number of feather pecks (gentle and severe) and aggressive pecks received, and on the part of the body that was pecked. Scoring of feather and skin damage focused on the same 11 parts of the body. Increasing numbers of aggressive pecks received were associated with decreased body weight and increased feather damage at the ages of 27 and 32 weeks. The number of severe feather pecks received was significantly related with feather damage at all ages; however, no relation with gentle feather pecks received was found. Group size had a significant effect on feather condition, with large group sizes having most feather damage.