Genetic information from progeny trials: a comparison between progenies generated by open pollination and by controlled crosses

When conifer progenies generated by open pollination are assessed in field tests, it is usually assumed that all progenies of the same mother are true half-sibs. This assumption may be invalid, leading to overestimation of additive genetic variation and heritability and to biased breeding values. From one Scots pine (Pinus sylvestris) and one Norway spruce (Picea abies) seed orchard, containing 28 and 36 parent clones respectively, progenies generated by open pollination (OP) and by controlled crosses (CC) were planted in adjacent trials at two to three sites in southern Sweden. The tree height and diameter at breast height were measured and genetic parameters based on these traits were estimated for OP and CC progenies separately, in order to enable comparisons. Narrow sense heritability estimates for Scots pine and Norway spruce OP progenies (in the ranges 0.04–0.13 and 0.15–0.38, respectively) did not differ significantly from CC estimates (0.07–0.12 and 0.23–0.30), suggesting that OP-based heritability values were not overestimated to any great extent. Similarly, genetic correlations between OP and CC progenies were in the ranges 0.87–0.88 and 0.74–0.77 for Scots pine and Norway spruce, respectively, being significantly lower than unity only in the case of Norway spruce. OP-based breeding values for both species should therefore correspond well with those predicted from CC progenies, albeit not perfectly for Norway spruce. In conclusion, the assumption of true half-sibs for OP progenies was not violated to the extent that genetic parameter estimates or breeding value predictions were seriously biased

Genetic improvement of sawn-board shape stability in Scots pine (Pinus sylvestris L.)

Adequate shape stability is a prerequisite for utilization of sawn boards in the building industry. This study investigated the possibility of indirect genetic improvement of Scots pine (Pinus sylvestris L.) sawn-board shape stability (specifically the bow, crook and twist) via selective breeding based on traits that can be non-destructively measured on standing trees. Relationships between shape stability and wood quality traits measured on logs and sawn boards were also determined. A total of 1896 standing trees from a 39-year-old Scots pine full-sib progeny test were non-destructively measured. A subset of 496 trees was harvested and sawn into 50 x 100 mm boards, the quality of which was assessed both non-destructively and destructively. Among the traits assessed on standing trees, grain angle (GRA) appeared to be the best predictor of sawn-board twisting and crooking (r(A) = 0.84 and 0.62, respectively). The individual-tree narrow-sense heritability (h(i)(2)) was moderate for twist and GRA (0.37 and 0.40, respectively), low for bow (0.21) and very low for crook (0.05). Selective breeding targeting lower GRA would result in lower twist and crook but could also increase sawn-board density, stiffness and strength

Logging Mats and Logging Residue as Ground Protection during Forwarder Traffic along Till Hillslopes

Forest soils in Northern Europe are generally trafficked by forest machinery on several occasions during a forest rotation. This may create ruts (wheel tracks), which could increase sediment transport to nearby surface water, reduce recreational value, and affect tree growth. It is therefore important to reduce soil disturbance during off-road forest transportation. In this study, rut depth was measured following forwarder traffic on study plots located along four harvested till hillslopes in Northern Sweden with drier soil conditions uphill and wet conditions downhill. The treatments included driving 1) using no ground protection, 2) on logging residue (on average, 38–50 kg m–2) and 3) on logging mats measuring 5×1×0.2 m. The hillslopes contain areas with a high content of boulders, stones, and gravel as well as areas with a significant content of silt. Six passes with a laden forwarder with four bogie tracks were performed. On the plots with ground protection, the application of logging residue and the application and removal of logging mats necessitated additional passes. Rut depth was measured using two methods: 1) as the difference in elevation between the interpolated original soil surface and the surface of the rut using GNSS positioning (Global Navigation Satellite Systems), and 2) manually with a folding rule from an aluminium profile, placed across the rut, to the bottom of the rut. The two methods generally gave similar results. Driving without ground protection in the upper part of the hillslopes generated ruts with depths <0.2 m. Here, the rut depth was probably modified by the high content of boulders and stones in the upper soil and drier soil conditions. In the lower part of the hillslopes, the mean rut depth ranged from 0.21 to 0.34 m. With a few exceptions, driving on logging residue or logging mats prevented exposure of mineral soil along the entire hillslope. Soil disturbance can thus be reduced by acknowledging the onsite variability in ground conditions and considering the need for ground protection when planning forest operations

Using traffic data to estimate wildlife populations

Wildlife populations are threatened worldwide by, among others, habitat fragmentation and hunting pressure. An important impediment for the large scale, national and regional, management of the populations is the difficulty to quantify population dynamics. The purpose of this study is to present a tool for such estimations which is based on available data in several countries; traffic load and traffic accidents with wildlife. An econometric model is developed, which accounts for landscape characteristics. It is applied to wild boar in Sweden, for which data on traffic load and accidents for different counties and years are available. Landscape characteristics are introduced with direct or indirect effects on population growth. The indirect landscape model gives the best statistical performance, and the results show relatively small differences in calculated intrinsic growth rate among counties but considerable differences in predicted population developments

Scots pine transfer effect models for growth and survival in Sweden and Finland

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Genomic data provide new insights on the demographic history and the extent of recent material transfers in Norway spruce

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

Mucin 4 and matrix metalloproteinase 7 as novel salivary biomarkers for periodontitis

Aim: Periodontitis is a chronic inflammatory disease, characterized by irreversible destruction of tooth-supporting tissue including alveolar bone. We recently reported mucin 4 ( MUC4) and matrix metalloproteinase 7 (MMP7) as highly associated with periodontitis in gingival tissue biopsies. The aim of this study was to further investigate the levels of MUC4 and MMP7 in saliva and gingival crevicular fluid (GCF) samples of patients with periodontitis. Materials and Methods: Saliva and GCF samples were collected from periodontitis patients and healthy controls. The levels of MUC4, MMP7, and total protein concentrations were analysed using ELISA or Bradford assay. Results: MUC4 levels were significantly lower in saliva and GCF from periodontitis patients relative to healthy controls. MMP7 levels were significantly higher in saliva and GCF from periodontitis patients. Multivariate analysis revealed that MUC4 was significantly associated with periodontitis after adjusting for age and smoking habits and, moreover, that the combination of MUC4 and MMP7 accurately discriminated periodontitis from healthy controls. Conclusions: MUC4 and MMP7 may be utilized as possible novel biomarkers for periodontitis.Peer reviewe