Primeval forests are today exceedingly rare in Europe, and transfer of forest reproductive material for afforestation and improvement has been very common, especially over the last two centuries. This can be a serious impediment when inferring past population movements in response to past climate changes such as the last glacial maximum (LGM), some 18,000 years ago. In the present study, we genotyped 1,672 individuals from three Picea species ( P. abies , P. obovata , and P. omorika ) at 400K SNPs using exome capture to infer the past demographic history of Norway spruce ( P. abies ) and estimate the amount of recent introduction used to establish the Norway spruce breeding program in southern Sweden. Most of these trees belong to P. abies and originate from the base populations of the Swedish breeding program. Others originate from populations across the natural ranges of the three species. Of the 1,499 individuals stemming from the breeding program, a large proportion corresponds to recent introductions from mainland Europe. The split of P. omorika occurred 23 million years ago (mya), while the divergence between P. obovata and P. abies began 17.6 mya. Demographic inferences retrieved the same main clusters within P. abies than previous studies, that is, a vast northern domain ranging from Norway to central Russia, where the species is progressively replaced by Siberian spruce ( P. obovata ) and two smaller domains, an Alpine domain and a Carpathian one, but also revealed further subdivision and gene flow among clusters. The three main domains divergence was ancient (15 mya), and all three went through a bottleneck corresponding to the LGM. Approximately 17% of P. abies Nordic domain migrated from P. obovata ~103K years ago, when both species had much larger effective population sizes. Our analysis of genomewide polymorphism data thus revealed the complex demographic history of Picea genus in Western Europe and highlighted the importance of material transfer in Swedish breeding program.
The aim of this study was to determine the effect of matrix on the occurrence of hazel grouse (Bonasa bonasia) in habitat fragments. The study was conducted in two kinds of landscape: (1) an agricultural landscape, where the censused forest habitat fragments were surrounded by farmland, and (2) in an intensively managed forested landscape, where the censused habitat fragments were surrounded by nonhabitat coniferous forest. Occupied and unoccupied habitat fragments in the agricultural landscape differed significantly in distance to the nearest suitable continuous habitat, with hazel grouse occurring only in habitat fragments closer than 100 m from continuous forest. In the intensively managed forest landscape, the effect of isolation was less evident, but there might be a threshold around 2 km. Effects of isolation occurred over much shorter distances when the surrounding habitats consisted of farmland than when it was forested habitats. The size of the habitat fragments was important in both landscapes, with larger habitat fragments more often containing hazel grouse.
Infant feeding history was investigated in 72 celiac and 288 age-matched reference children in a retrospective questionnaire study. The reply rate was 100% in celiac and 91.6% in reference children. The celiac children were breast-fed for a significantly shorter time than reference children, and they were less often breast-fed at the introduction of gluten. The age of the children at gluten introduction was similar, but the celiac children were significantly more often introduced by a gluten-containing follow-up formula, while the reference children more often started on a gluten-containing porridge. The results can be interpreted in two ways. First, it could be argued that breast milk per se protects against symptoms of celiac disease in childhood. It could, however, also be claimed that breast-feeding merely modulates the gluten introduction, causing a less abrupt introduction of gluten in the baby diet and thereby fewer overt symptoms of the disease.
Norway spruce (Picea abies) is a dominant conifer species of major economic importance in northern Europe. Extensive breeding programs were established to improve phenotypic traits of economic interest. In southern Sweden, seeds used to create progeny tests were collected on about 3,000 trees of outstanding phenotype (‘plus’ trees) across the region. In a companion paper, we showed that some were of local origin but many were recent introductions from the rest of the natural range. The mixed origin of the trees together with partial sequencing of the exome of >1,500 of these trees and phenotypic data retrieved from the Swedish breeding program offered a unique opportunity to dissect the genetic basis of local adaptation of three quantitative traits (height, diameter and bud‐burst) and assess the potential of assisted gene flow. Through a combination of multivariate analyses and genome‐wide association studies, we showed that there was a very strong effect of geographical origin on growth (height and diameter) and phenology (bud‐burst) with trees from southern origins outperforming local provenances. Association studies revealed that growth traits were highly polygenic and bud‐burst somewhat less. Hence, our results suggest that assisted gene flow and genomic selection approaches could help to alleviate the effect of climate change on P. abies breeding programs in Sweden.
JANSSON, G. and J. MARTINSON, Studies on the ganglionic site of action of sympathetic I n acute experiments on cats anesthetized with chloralose, inhibition of excitatory vagal responses of gastric smooth muscle was produced by reflex or direct activation of a n adrenergic nerve fibre system. The reflex that could be elicited by distension of a jejunal loop or stimulation of mesenteric afferents was dependent on intact spinal connections because it was blocked by spinal anesthesia. Activation of the adrenergic nerve fibre system did not inhibit gastric myogenic tone or gastric muscle contraction elicited by the muscarinic action of acetylcholine. It was therefore concluded that the adrenergic outflow responsible for this type of inhibition acts on parasympathetic intramural ganglion cells involved in the excitatory control of gastric motility. ougow to the stomach. Acta physiol. scand. 1966. 68. 184-1 92.
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