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Silva Fennica 1926-1997
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Articles containing the keyword 'breeding'.

Category: Research article

article id 10076, category Research article
Tore Skrøppa, Arne Steffenrem. (2019). Genetic variation in phenology and growth among and within Norway spruce populations from two altitudinal transects in Mid-Norway. Silva Fennica vol. 53 no. 1 article id 10076. https://doi.org/10.14214/sf.10076
Highlights: Norway spruce populations distributed along each of two altitudinal transects showed strong clinal relationships between the annual mean temperatures of the sites of the populations and height and phenology traits in short term tests and height in field trials; Large variation was present among families within populations for height and phenology traits and with a wider range within than among populations; Correlation patterns among traits were different for provenances and families.

Progenies from open pollinated cones collected in natural populations of Norway spruce (Picea abies (L.) Karst.) distributed along two altitudinal transects in Mid-Norway were tested in the nursery, in short term tests and in long-term field trials. The populations showed clinal variation related to the mean annual temperatures of the populations, with the earliest bud flush and cessation of shoot elongation and lowest height at age nine years for the high altitude populations. Within population variation was considerable as the narrow sense heritability for these traits was 0.67, 0.31 and 0.09 in one transect and 0.55, 0.18 and 0.14 in the other transect, respectively. Lammas shoots occurred in the short term trials with large variation in frequency between years. There was significant family variation for this trait, but also interactions between populations and year. The variance within populations was considerably larger in the populations from low altitude compared to the high-altitude populations. Significant genetic correlations between height and phenology traits and damage scores indicate that families flushing early and ceasing growth late were taller. Taller families also had higher frequencies of damages. Selection of the top 20% families for height growth in short term tests at age nine years gave a simulated gain of 11% increased height growth at age 18 years in long term trials at altitudes similar to those of origin of the populations. The gain was negative when high altitude populations were selected based on testing in the lowland.

  • Skrøppa, Norwegian Institute of Bioeconomy Research, P.O. Box 115, 1431 Ås, Norway ORCID ID:E-mail: tore.skroppa@nibio.no (email)
  • Steffenrem, ORCID ID:E-mail:
article id 9914, category Research article
Jun Tanabe, Futoshi Ishiguri, Akira Tamura, Yuya Takashima, Jyunichi Ohshima, Kazuya Iizuka, Shinso Yokota. (2018). Within-tree radial and among-family variations in wood density, microfibril angle, and mechanical properties in Picea glehnii. Silva Fennica vol. 52 no. 2 article id 9914. https://doi.org/10.14214/sf.9914
Highlights: The modulus of elasticity was affected by both microfibril angle and wood density, whereas the modulus of rupture was mainly affected by wood density in Picea glehnii; A larger degree of among-family variation in wood properties was detected in juvenile wood than in mature wood, indicating that genetic improvements in the mechanical properties may be more effective for juvenile wood.

Genetic improvements in the mechanical properties of wood are important in forestry species used for lumber, such as Picea. The within-tree radial and among-family variations for the modulus of elasticity (MOE), modulus of rupture (MOR), and their related traits [i.e., microfibril angle (MFA) of the S2 layer in latewood tracheid and air-dry density (AD)] were evaluated in nine open-pollinated families of Picea glehnii (F. Schmidt) Mast. The radial variation in MOR was mainly affected by AD, whereas MOE was affected by MFA and AD. Higher F-values obtained by analysis of variance and coefficient of variation were observed for all properties at the 6th–15th annual ring, except for AD at the 6th–10th annual ring. This result suggests that the contribution of genetic effect is larger in these highly variable regions. In addition, positive correlation coefficients were obtained between wood properties at the 6th–15th annual ring and mean values of these properties. Therefore, genetic improvements for MOE, MOR, and their related traits in P. glehnii is likely to be more effective in juvenile wood, specifically at the 6th–15th annual ring from the pith.

  • Tanabe, Faculty of Education, Chiba University, Chiba, 263-8522, Japan ORCID ID:E-mail: tanabe_j@chiba-u.jp (email)
  • Ishiguri, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan ORCID ID:E-mail: ishiguri@cc.utsunomiya-u.ac.jp
  • Tamura, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Hitachi, 319-1301, Japan ORCID ID:E-mail: akirat@affrc.go.jp
  • Takashima, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Hitachi, 319-1301, Japan ORCID ID:E-mail: ytakashima@ffpri.affrc.go.jp
  • Ohshima, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan ORCID ID:E-mail: joshima@cc.utsunomiya-u.ac.jp
  • Iizuka, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan ORCID ID:E-mail: kiizuka@cc.utsunomiya-u.ac.jp
  • Yokota, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan ORCID ID:E-mail: yokotas@cc.utsunomiya-u.ac.jp
article id 7728, category Research article
Liam Donnelly, Sven-Olof Lundqvist, Conor O’Reilly. (2017). Inter- and intra-annual wood property variation in juvenile wood between six Sitka spruce clones. Silva Fennica vol. 51 no. 4 article id 7728. https://doi.org/10.14214/sf.7728
Highlights: Wood property differences resulted primarily from variation in the proportions of early- and latewood in each annual ring; Width of early- and latewood bands in each ring was found to be a more important determinant of juvenile wood quality than the characteristics of the cells within each band; Wood properties differed greatly between clones, suggesting that there is potential to improve juvenile wood properties through selective breeding.

Increased growth rates have reduced rotation lengths, increasing the proportion of juvenile wood relative to mature wood, which may negatively affect mechanical performance of sawn timber. However, there is limited information available on the potential impact of breeding for vigour on juvenile wood in Sitka spruce (Picea sitchensis (Bong.) Carrière). In this study, the relationship between vigour (based on total height) and wood properties was investigated in six-year-old Sitka spruce clones grown in two replicated field trials in Ireland. Six clones were evaluated, two clones from each of three vigour (high, intermediate and low) classes. Discs were cut from the base of one ramet per replication for each clone to assess wood quality attributes. Radial tracheid width was significantly and positively correlated with ring width and height, and was negatively correlated with density. The wood of the most vigorous clone had significantly larger ring width with thinner cell walls and wider tracheids than all clones in the two other vigour classes, resulting in lower mean wood density. Latewood properties for all wood attributes measured differed significantly between the two sites. Wood property differences resulted primarily from variation in the proportions of early- and latewood in each annual ring. Additionally, the width of early- and latewood bands in each ring was found to be a more important determinant of juvenile wood quality than the characteristics of the cells within each band. Wood properties differed greatly between clones, suggesting that there is potential to improve juvenile wood properties through selective breeding.

  • Donnelly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland ORCID ID:E-mail: liam.donnelly@ucdconnect.ie (email)
  • Lundqvist, Innventia Ab, Drottning Kristinas väg 61, SE-114 86 Stockholm, Sweden ORCID ID:E-mail: svenolof.lundqvist@innventia.com
  • O’Reilly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland ORCID ID:E-mail: conor.oreilly@ucd.ie
article id 1743, category Research article
Gintare Sabalinkiene, Darius Danusevicius, Michael Manton, Gediminas Brazaitis, Kastytis Simkevicius. (2017). Differentiation of European roe deer populations and ecotypes in Lithuania based on DNA markers, cranium and antler morphometry. Silva Fennica vol. 51 no. 3 article id 1743. https://doi.org/10.14214/sf.1743
Highlights: Lithuanian roe deer populations are genetically structured into southern and northern groups, most likely affected by a divergent gene flow and Lithuania’s largest rivers slowing down migration; Microsatellite and skull morphology based genetic differentiation between field and forest ecotypes are weak; Geographical location has a significant effect on antler morphometry traits and skull size of male roe deer, the latter increasing northwards.

The objective of our study was to assess the genetic and morphological differentiation of European roe deer (Capreolus capreolus L.) in Lithuania based on DNA markers, skull and anther morphology. DNA was extracted from 79 culled individuals at 13 locations and genotyped at five nuclear microsatellite loci. Based on culling location, individuals were assigned to either a field (N = 43) or a forest ecotype (N = 36). Skull and antler morphometry was studied on 603 and 292 individuals, respectively. Results showed no significant genetic and skull morphology differentiation between the ecotypes. The forest ecotype tends to exhibit lower genetic diversity compared to the field ecotype, particularly for male individuals. The genetic differentiation of roe deer in Lithuania was significant based on the RST values, but not on the FST values. A STRUCTURE analyses revealed southern and northern genetic clusters, most likely affected by divergent gene flow. The country’s major rivers Nemunas and Neris are likely to increase differentiation between the clusters. ANOVA on skull morphology by gender and age indicated a significant effect of geographical location. Skull size (especially length) is greater in the northern part of the country. We also found significant effects of age, ecotype and geographical location on most of the roe deer male antler morphometric traits.

  • Sabalinkiene, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania ORCID ID:E-mail: gintare.sabalinkiene@asu.lt (email)
  • Danusevicius, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania ORCID ID:E-mail: darius.danusevicius@asu.lt
  • Manton, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania ORCID ID:E-mail: michael.manton@asu.lt
  • Brazaitis, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania ORCID ID:E-mail: gediminas.brazaitis@asu.lt
  • Simkevicius, Institute of Forest Biology and Silviculture, Faculty of Forest Sciences and Ecology, Aleksandras Stulginskis University, Studentu street 11, Akademija, Kaunas district, Lithuania ORCID ID:E-mail: kastytis.simkevicius@asu.lt
article id 1562, category Research article
Mats Erik Berlin, Torgny Persson, Gunnar Jansson, Matti Haapanen, Seppo Ruotsalainen, Lars Bärring, Bengt Andersson Gull. (2016). Scots pine transfer effect models for growth and survival in Sweden and Finland. Silva Fennica vol. 50 no. 3 article id 1562. https://doi.org/10.14214/sf.1562
Highlights: Scots pine transfer effect models for growth and survival, valid in both Sweden and Finland have been developed; The models use high-resolution gridded climate data and can predict performance in future climatic conditions; The models perform well both for unimproved and genetically improved material and can be used to develop deployment recommendations of contemporary forest regeneration material in Sweden and Finland.

In this study, we developed models of transfer effects for growth and survival of Scots pine (Pinus sylvestris L.) in Sweden and Finland using a general linear mixed-model approach. For model development, we used 378 provenance and progeny trials with a total of 276 unimproved genetic entries (provenances and stand seed check-lots) distributed over a wide variety of climatic conditions in both countries. In addition, we used 119 progeny trials with 3921 selected genetic entries (open- and control pollinated plus-tree families) for testing model performance. As explanatory variables, both climatic indices derived from high-resolution gridded climate datasets and geographical variables were used. For transfer, latitude (photoperiod) and, for describing the site, temperature sum were found to be main drivers for both survival and growth. In addition, interaction terms (between transfer in latitude and site altitude for survival, and transfer in latitude and temperature sum for growth) entail changed reaction patterns of the models depending on climatic conditions of the growing site. The new models behave in a way that corresponds well to previous studies and recommendations for both countries. The model performance was tested using selected plus-trees from open and control pollinated progeny tests. Results imply that the models are valid for both countries and perform well also for genetically improved material. These models are the first step in developing common deployment recommendations for genetically improved forest regeneration material in both Sweden and Finland.

  • Berlin, Uppsala Science Park, SE-75183 Uppsala, Sweden ORCID ID:E-mail: mats.berlin@skogforsk.se (email)
  • Persson, Skogforsk, Box 3, SE-91821 Sävar, Sweden ORCID ID:E-mail: torgny.persson@skogforsk.se
  • Jansson, Uppsala Science Park, SE-75183 Uppsala, Sweden ORCID ID:E-mail: gunnar.jansson@skogforsk.se
  • Haapanen, Natural Resources Institute Finland (Luke), Green Technology, Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: matti.haapanen@luke.fi
  • Ruotsalainen, Natural Resources Institute Finland (Luke), Green Technology, Finlandiantie 18, FI-58450 Punkaharju, Finland ORCID ID:E-mail: seppo.ruotsalainen@luke.fi
  • Bärring, Rossby Centre, Swedish Meteorological and Hydrological Institute, Folkborgsvägen 17, SE-60176 Norrköping, Sweden ORCID ID:E-mail: lars.barring@smhi.se
  • Andersson Gull, Skogforsk, Box 3, SE-91821 Sävar, Sweden ORCID ID:E-mail: bengt.andersson@skogforsk.se
article id 901, category Research article
Luis A. Apiolaza, Rosa M. Alzamora. (2013). Building deployment portfolios for genotypes under performance instability. Silva Fennica vol. 47 no. 1 article id 901. https://doi.org/10.14214/sf.901
We used portfolio theory to analyze the tradeoffs between returns and performance instability of deployment units for Pinus radiata D. Don. We considered three groups of 34 trees each grown to produce appearance lumber, structural lumber, or both. Risk was based on the variability of tree returns in scenarios of changing volume, wood stiffness and presence of resin defects due to genotype by environment interaction inducing both changes of scale and differential tree response to environmental scenarios. The return of structural trees was highly variable with a mean of 3.11 NZ $/stem/year, followed by appearance-structural trees (3.48 NZ $/stem/year). In contrast, appearance trees had the lowest returns (1.99 NZ $/stem/year) and variability. The portfolio model selected structural trees in high-risk scenarios, but selection was apportioned between structural and appearance-structural trees as the risk decreased. The model selected only appearance trees for high-risk aversion. The analysis also considered silvicultural regimes, where the appearance-structural regime was selected under high variability. As risk decreased the appearance grades regime was also selected. The structural regime was rarely selected due to the variability of stiffness between trees. Using genotypes improved for stiffness could increase the expected value and reduce variability for structural purposes, making the structural regime more appealing.
  • Apiolaza, School of Forestry, University of Canterbury, Private Bag 4800, 8042 Canterbury, New Zealand ORCID ID:E-mail: luis.apiolaza@canterbury.ac.nz (email)
  • Alzamora, Instituto de Manejo Forestal, Universidad Austral, Valdivia, Chile ORCID ID:E-mail: ralzamor@uach.cl
article id 132, category Research article
Mats Berlin, Lars Lönnstedt, Gunnar Jansson, Öje Danell, Tore Ericsson. (2010). Developing a Scots pine breeding objective: a case study involving a Swedish sawmill. Silva Fennica vol. 44 no. 4 article id 132. https://doi.org/10.14214/sf.132
The aim of this study was to develop a Scots pine (Pinus sylvestris L.) breeding objective for a vertically integrated sawmill in northern Sweden. The production system was defined as comprising the sawmill and the forests supplying it. Volume per hectare, wood density, survival and straightness were used as objective traits and the related selection criteria were measurements, collected at young tree age, of height, diameter, pilodyn penetration, vitality and straightness. A bio-economic model was used to calculate economic weights for the objective traits identified. We also investigated the efficiency of different selection indices based on these economic weights, in combination with available data on genetic parameters. Furthermore, we studied the effect of different discount rates on the calculated economic weights. The results showed that, compared to the full index (which included all selection criteria), omitting either vitality or straightness had a negligible effect, reducing predicted profit gain per hectare by less than one per cent. Height or diameter each had a greater effect, with a loss of predicted profit gain per hectare of up to 6%. Excluding pilodyn penetration from the selection index caused the largest reduction in predicted profit gain per hectare, amounting to over 10%. However, when both height and diameter were removed the predicted profit gain per hectare dropped to one-third of that based on the full index. Finally, ranking and genetic selection for the developed breeding objective was insensitive to changes in the discount rate.
  • Berlin, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: mats.berlin@skogsforsk.se (email)
  • Lönnstedt, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Jansson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Danell, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Ericsson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
article id 154, category Research article
Henrik R. Hallingbäck, Gunnar Jansson, Björn Hannrup, Anders Fries. (2010). Which annual rings to assess grain angles in breeding of Scots pine for improved shape stability of sawn timber? Silva Fennica vol. 44 no. 2 article id 154. https://doi.org/10.14214/sf.154
The shape stability properties of sawn timber could be improved by breeding or grading Scots pine (Pinus sylvestris L.) for reduced grain angles. Currently, only grain angle assessments performed in single annual rings can be considered feasible in forest breeding programmes. The relevance of such methods in assessing shape stability traits was evaluated by taking grain angle measurements beneath the bark in a 36-year-old Scots pine progeny trial. Several grain angle measurements from stem discs were also taken from a sample of 162 trees. Phenotypic correlations were estimated between grain angle and the bow, crook and twist developed in 316 sawn and dried boards. All single annual ring assessments, including measurements taken directly under the bark, were significantly correlated with twist. The highest correlations (0.60–0.70) were observed in annual rings numbered 8–20 and at distances of 30–70 mm from the pith, indicating those parts of logs where grain angles have the largest impact on twist. These results suggests, that grain angles measured beneath the bark are relevant to the twist of sawn small timber, and that any single annual ring could be chosen for the assessment, provided that the tree diameter is within the 60–140 mm range. No appreciable correlations were observed between grain angles and either crook or bow.
  • Hallingbäck, Dept of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden ORCID ID:E-mail: henrik.hallingback@vbsg.slu.se (email)
  • Jansson, The Forestry Research Institute of Sweden, Uppsala, Sweden ORCID ID:E-mail:
  • Hannrup, The Forestry Research Institute of Sweden, Uppsala, Sweden ORCID ID:E-mail:
  • Fries, Dept of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden ORCID ID:E-mail:
article id 291, category Research article
Yildiray Lise, Zeki Kaya, Fikret Isik, Rumi Sabuncu, Irfan Kandemir, Sertaç Önde. (2007). The impact of over-exploitation on the genetic structure of Turkish red pine (Pinus brutia Ten.) populations determined by RAPD markers. Silva Fennica vol. 41 no. 2 article id 291. https://doi.org/10.14214/sf.291
To determine the possible impact of over-exploitation on the genetic structure of Turkish red pine (Pinus brutia Ten.) populations, three natural and three over-exploited (human degraded) populations of the species in the Mediterranean region of Turkey were investigated with Randomly Amplified Polymorphic DNA (RAPD). With the 80 RAPD primers tested, 12 of them yielded 137 polymorphic RAPD fragments. Four of the studied populations maintained unique fragments. The mean proportion of polymorphic fragments for all populations ranged from 89.8 to 98.9% and there were no significant differences between natural (94.8%) vs. over-exploited populations (92.7%). The estimated heterozygosity values suggested that Turkish red pine maintains high levels of genetic diversity (range 0.24–0.28) though studied populations and grouped ones as natural (He = 0.28) vs. over-exploited (0.27) did not differ significantly. The mean FST value indicated that the large portion of the total genetic diversity was within populations (93%), but this value was lower in the natural populations (92%) than in the over-exploited ones (94%). In over-exploited populations, excess of homozygosity was observed (about 6% higher) as compared to natural populations, indicating impacts of inbreeding in P. brutia.
  • Lise, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey ORCID ID:E-mail:
  • Kaya, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey ORCID ID:E-mail: kayaz@metu.edu.tr (email)
  • Isik, North Carolina State University, Raleigh, USA ORCID ID:E-mail:
  • Sabuncu, Southwest Anatolia Forest Research Institute, Antalya, Turkey ORCID ID:E-mail:
  • Kandemir, Department of Biology, Zonguldak Karaelmas University, 67100, Zonguldak, Turkey ORCID ID:E-mail:
  • Önde, Department of Biological Sciences, Middle East Technical University, 06531, Ankara, Turkey ORCID ID:E-mail:

Category: Review article

article id 1660, category Review article
Lars Rytter, Morten Ingerslev, Antti Kilpeläinen, Piritta Torssonen, Dagnija Lazdina, Magnus Löf, Palle Madsen, Peeter Muiste, Lars-Göran Stener. (2016). Increased forest biomass production in the Nordic and Baltic countries – a review on current and future opportunities. Silva Fennica vol. 50 no. 5 article id 1660. https://doi.org/10.14214/sf.1660
Highlights: Annual growth is 287 million m3 in the forests of the Nordic and Baltic countries; Growth can be increased by new tree species, tree breeding, high-productive management systems, fertilization and afforestation of abandoned agricultural land; We predict a forest growth increment of 50–100% is possible at the stand scale; 65% of annual growth is harvested today.

The Nordic and Baltic countries are in the frontline of replacing fossil fuel with renewables. An important question is how forest management of the productive parts of this region can support a sustainable development of our societies in reaching low or carbon neutral conditions by 2050. This may involve a 70% increased consumption of biomass and waste to meet the goals. The present review concludes that a 50–100% increase of forest growth at the stand scale, relative to today’s common level of forest productivity, is a realistic estimate within a stand rotation (~70 years). Change of tree species, including the use of non-native species, tree breeding, introduction of high-productive systems with the opportunity to use nurse crops, fertilization and afforestation are powerful elements in an implementation and utilization of the potential. The productive forests of the Nordic and Baltic countries cover in total 63 million hectares, which corresponds to an average 51% land cover. The annual growth is 287 million m3 and the annual average harvest is 189 million m3 (65% of the growth). A short-term increase of wood-based bioenergy by utilizing more of the growth is estimated to be between 236 and 416 TWh depending on legislative and operational restrictions. Balanced priorities of forest functions and management aims such as nature conservation, biodiversity, recreation, game management, ground water protection etc. all need consideration. We believe that these aims may be combined at the landscape level in ways that do not conflict with the goals of reaching higher forest productivity and biomass production.

  • Rytter, The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-26890 Svalöv, Sweden ORCID ID:E-mail: lars.rytter@skogforsk.se (email)
  • Ingerslev, Copenhagen University, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark ORCID ID:E-mail: moi@ign.ku.dk
  • Kilpeläinen, Finnish Environment Institute, Joensuu Office, P.O. Box 111, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.kilpelainen@ymparisto.fi
  • Torssonen, University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: Piritta.Torssonen@uef.fi
  • Lazdina, Latvian State Forest Research Institute “Silava”, 111 Riga str, Salaspils, LV 2169 Latvia ORCID ID:E-mail: Dagnija.Lazdina@silava.lv
  • Löf, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49 SE-230 53 Alnarp, Sweden ORCID ID:E-mail: magnus.lof@slu.se
  • Madsen, Copenhagen University, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark ORCID ID:E-mail: pam@ign.ku.dk
  • Muiste, Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Dept. Forest Industry, Kreutzwaldi 5, Tartu 51014, Estonia ORCID ID:E-mail: Peeter.Muiste@emu.ee
  • Stener, The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-26890 Svalöv, Sweden ORCID ID:E-mail: Lars-Goran.Stener@skogforsk.se

Category: Article

article id 5608, category Article
Harri Mäkinen. (1997). Possibilities of competition indices to describe competitive differences between Scots pine families. Silva Fennica vol. 31 no. 1 article id 5608. https://doi.org/10.14214/sf.a8509

Possibilities of distance-independent and -dependent competition indices to describe the competition stress of an individual tree was studied in Southern Finland. Five half-sib open-pollinated families and one check lot of Scots pine (Pinus sylvestris L.) was used as study material in order to analyse competitive interactions of crown form and stand density variation. Almost all competition indices correlated strongly with radial increment. Thus distance-independent indices were adequate to describe competition in young row plantations, where distance effects between trees were implicitly eliminated. Correlations between indices and height increment were not significant. Along with the increase in competition, the width and length of the crown and the diameter increment of the stem of some narrow-crowned families decreased slowly compared to wide-crowned families.

  • Mäkinen, ORCID ID:E-mail:
article id 5539, category Article
Tore Skrøppa. (1994). Impacts of tree improvement on genetic structure and diversity of planted forests. Silva Fennica vol. 28 no. 4 article id 5539. https://doi.org/10.14214/sf.a9179

After a presentation of basic biodiversity concepts, reviews are made of studies reporting genetic implications of tree improvement activities: seed treatments, seedling production, provenance transfers, plus tree selection, seed production in seed orchards and progeny testing.

Several of the activities may influence the genetic structure and diversity of the planted forests. The general conclusion is, however, that planted forests are at least as genetically diverse as the natural stands that they replace. The diversity in forest management and use is best assurance for the future adaptability of the forests.

  • Skrøppa, ORCID ID:E-mail:
article id 5467, category Article
E. K. Morgenstern, Y. S. Park. (1991). Breeding of Picea mariana (Mill.) B.S.P.: seed orchard and clonal approaches. Silva Fennica vol. 25 no. 4 article id 5467. https://doi.org/10.14214/sf.a15625

During the past 30 years, genetics research has accumulated much information on black spruce (Picea mariana). The adoption of less intensive and faster plustree selection, establishment of seedling seed orchards and family selection significantly increased the rate of progress in improvement of the species. In New Brunswick this approach made it possible to obtain substantial quantities of seeds 10 years after the initiation of the program, and now all the seeds used in reforestation are derived from seed orchards.

Fourteen years after beginning the black spruce breeding program, second generation breeding is underway. The possibility of implementing alternative breeding strategies using ”breeding – cloning” procedures are explored for the advanced generation. Until somatic embryogenesis techniques become fully operational, ”backward selection” schemes and crossing in breeding halls followed by vegetative multiplication using serial rooted cuttings can be adopted. Larger genetic gains than those from conventional breeding are expected not only from the utilization of both additive and non-additive variances, but also from the elimination of inefficiencies of large conventional seed orchards.

  • Morgenstern, ORCID ID:E-mail:
  • Park, ORCID ID:E-mail:
article id 5467, category Article
E. K. Morgenstern, Y. S. Park. (1991). Breeding of Picea mariana (Mill.) B.S.P.: seed orchard and clonal approaches. Silva Fennica vol. 25 no. 4 article id 5467. https://doi.org/10.14214/sf.a15625

During the past 30 years, genetics research has accumulated much information on black spruce (Picea mariana). The adoption of less intensive and faster plustree selection, establishment of seedling seed orchards and family selection significantly increased the rate of progress in improvement of the species. In New Brunswick this approach made it possible to obtain substantial quantities of seeds 10 years after the initiation of the program, and now all the seeds used in reforestation are derived from seed orchards.

Fourteen years after beginning the black spruce breeding program, second generation breeding is underway. The possibility of implementing alternative breeding strategies using ”breeding – cloning” procedures are explored for the advanced generation. Until somatic embryogenesis techniques become fully operational, ”backward selection” schemes and crossing in breeding halls followed by vegetative multiplication using serial rooted cuttings can be adopted. Larger genetic gains than those from conventional breeding are expected not only from the utilization of both additive and non-additive variances, but also from the elimination of inefficiencies of large conventional seed orchards.

  • Morgenstern, ORCID ID:E-mail:
  • Park, ORCID ID:E-mail:
article id 5466, category Article
Hely Häggman. (1991). Application of biotechnology to forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5466. https://doi.org/10.14214/sf.a15624

Forest tree breeding involves manipulation of genetic composition of populations and individuals, and biotechnology focuses on selected individuals. The new techniques cannot replace the conventional breeding techniques but both need effective cooperation of each other. Thus, the distinction between conventional breeding and biotechnology is artificial. The biotechnology methods are new and fast developing and the future with field and progeny testing will show which techniques will be permanently adopted into tree breeding. For instance, the earlier hope of the use of somaclonal variation as a new source of variability and a powerful tool for the breeder seem today quite the opposite. Somaclonal variation constituting a major problem in present-day micropropagation is due to the unpredictable variation. Based on knowledge of today, especially micropropagation via somatic embryos, transgenic trees and the identification of major genes seem to be good candidates to be permanently adopted into tree breeding.

  • Häggman, ORCID ID:E-mail:
article id 5466, category Article
Hely Häggman. (1991). Application of biotechnology to forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5466. https://doi.org/10.14214/sf.a15624

Forest tree breeding involves manipulation of genetic composition of populations and individuals, and biotechnology focuses on selected individuals. The new techniques cannot replace the conventional breeding techniques but both need effective cooperation of each other. Thus, the distinction between conventional breeding and biotechnology is artificial. The biotechnology methods are new and fast developing and the future with field and progeny testing will show which techniques will be permanently adopted into tree breeding. For instance, the earlier hope of the use of somaclonal variation as a new source of variability and a powerful tool for the breeder seem today quite the opposite. Somaclonal variation constituting a major problem in present-day micropropagation is due to the unpredictable variation. Based on knowledge of today, especially micropropagation via somatic embryos, transgenic trees and the identification of major genes seem to be good candidates to be permanently adopted into tree breeding.

  • Häggman, ORCID ID:E-mail:
article id 5465, category Article
Gösta Eriksson. (1991). Challenges for forest geneticists. Silva Fennica vol. 25 no. 4 article id 5465. https://doi.org/10.14214/sf.a15623

Studies of phenotypic as well as mixed population plasticities are urgently needed in a world that supposedly experiences a gradual change of its environment. It is important to understand that man creates his environment and silviculture. This is one of the reasons why for breeding it cannot be expected to find optimal phenotypes in nature. Other reasons are the phylogenetic constraints and migration of pollen and seeds.

Forest genetics up to now is characterized by the study of one trait at a time. There is an urgent need for simultaneous analysis of several traits by the aid of genetic correlations or multivariate analysis. Generally there is a need for inclusion of larger numbers of genetic entries in forest genetic investigations.

For the long-rotation-time species there is a need to determine the curves for degree of dormancy and hardiness during the annual cycle. Information of plasticity in two-dimensional environments like water availability and temperature is needed. Studies on nutrient utilization and acquisition will tell us whether or not we must have different breeding populations for different soil fertilities. An understanding of the phase changes between juvenile and adult opens up possible applications such as faster generation turn-over in the breeding population via early flowering and early testing as well as better plants for frost-prone and weedy sites.

  • Eriksson, ORCID ID:E-mail:
article id 5464, category Article
Donald I. Dickmann. (1991). Role of physiology in forest tree improvement. Silva Fennica vol. 25 no. 4 article id 5464. https://doi.org/10.14214/sf.a15622

The paper introduces different ways plant physiology research can avail the process of tree improvement. The breeding of tree cultivars that efficiently produce a particular wood product or amenity will be an important aspect of forest management. What physiologist can provide to breeders and genetic engineers is the opportunity to move their work from empirical level towards a more theoretical level, and help to make breeding more predictable and more precise in its objectives. The areas of research discussed in the paper are biotechnology, flowering, selection criteria, adaptability and application of ideotypes.

  • Dickmann, ORCID ID:E-mail:
article id 5463, category Article
Öje Danell. (1991). Survey of past, current and future Swedish forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5463. https://doi.org/10.14214/sf.a15621

The paper gives an introduction of the tree breeding program of Sweden that started in 1936 by the establishment of an association for the tree breeding. In 1967 the Institute of Forest Improvement was founded and it replaced the earlier association. The main species in the programme have been Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), lately also birch (mainly Betula pendula Roth.) and lodgepole pine (Pinus contorta). In addition, limited breeding has been done also with hybrid aspen (Populus tremula x P. tremuloides), oak (Quercus), larch (Larix), black spruce (Picea mariana) and a few other native and exotic species. The dominating initial effort has been to select plustrees in natural stands and use them for production of reforestation material. In addition, a considerable body of tests was built. The paper lists the status of breeding material of the different tree species and introduces the medium and short-term breeding programmes.

  • Danell, ORCID ID:E-mail:
article id 5463, category Article
Öje Danell. (1991). Survey of past, current and future Swedish forest tree breeding. Silva Fennica vol. 25 no. 4 article id 5463. https://doi.org/10.14214/sf.a15621

The paper gives an introduction of the tree breeding program of Sweden that started in 1936 by the establishment of an association for the tree breeding. In 1967 the Institute of Forest Improvement was founded and it replaced the earlier association. The main species in the programme have been Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), lately also birch (mainly Betula pendula Roth.) and lodgepole pine (Pinus contorta). In addition, limited breeding has been done also with hybrid aspen (Populus tremula x P. tremuloides), oak (Quercus), larch (Larix), black spruce (Picea mariana) and a few other native and exotic species. The dominating initial effort has been to select plustrees in natural stands and use them for production of reforestation material. In addition, a considerable body of tests was built. The paper lists the status of breeding material of the different tree species and introduces the medium and short-term breeding programmes.

  • Danell, ORCID ID:E-mail:
article id 5461, category Article
Run-Peng Wei, Dag Lindgren. (1991). Selection effects on diversity and genetic gain. Silva Fennica vol. 25 no. 4 article id 5461. https://doi.org/10.14214/sf.a15619

Four different methods of truncation selection were studied in a population consisting of a large number of unrelated full sib families of equal size: phenotype selection, family selection, within-family selection and combined index selection (optimal weighting of individual and family performance to get the best prediction of breeding value). Methods were developed for calculating diversity (”relative effective family number”) for the different selection methods. Numerical calculations were made for genetic gain and diversity. Model assumptions are additive gene control and normal distribution. Phenotypic was good at high heritabilities and between family at low heritabilities. Loss of diversity was strongly dependent on selection method and selection strength. Compared at the same diversity, genetic gain was lower for combined index compared to phenotypic. There is a need for methods combining the goals gain and diversity.

The PDF includes an abstract in Finnish.

  • Wei, ORCID ID:E-mail:
  • Lindgren, ORCID ID:E-mail:
article id 5461, category Article
Run-Peng Wei, Dag Lindgren. (1991). Selection effects on diversity and genetic gain. Silva Fennica vol. 25 no. 4 article id 5461. https://doi.org/10.14214/sf.a15619

Four different methods of truncation selection were studied in a population consisting of a large number of unrelated full sib families of equal size: phenotype selection, family selection, within-family selection and combined index selection (optimal weighting of individual and family performance to get the best prediction of breeding value). Methods were developed for calculating diversity (”relative effective family number”) for the different selection methods. Numerical calculations were made for genetic gain and diversity. Model assumptions are additive gene control and normal distribution. Phenotypic was good at high heritabilities and between family at low heritabilities. Loss of diversity was strongly dependent on selection method and selection strength. Compared at the same diversity, genetic gain was lower for combined index compared to phenotypic. There is a need for methods combining the goals gain and diversity.

The PDF includes an abstract in Finnish.

  • Wei, ORCID ID:E-mail:
  • Lindgren, ORCID ID:E-mail:
article id 5457, category Article
Hans Roulund, Tore Skrøppa. (1991). Summary of main topics and conclusions from the meeting. Silva Fennica vol. 25 no. 4 article id 5457. https://doi.org/10.14214/sf.a15615

This paper summarises the main topics and conclusions from the joint meeting of two IUFRO working parties, S2.04-02, Breeding theory and progeny testing, and S2.02-16, Seed orchards, held in Tuusula, Finland on September 10–15, 1991. It concludes the main topics that need more research in these disciplines and future trends in the research.

  • Roulund, ORCID ID:E-mail:
  • Skrøppa, ORCID ID:E-mail:
article id 5456, category Article
Veikko Koski. (1991). Biological systems in tree breeding. Silva Fennica vol. 25 no. 4 article id 5456. https://doi.org/10.14214/sf.a15614

This issue of Silva Fennica includes the presentations given in a joint meeting of two IUFRO working parties, S2.04-02, Breeding theory and progeny testing, and S2.02-16, Seed orchardsThe sessions were held in Tuusula, Finland on September 10–15, 1991.

  • Koski, ORCID ID:E-mail:
article id 5423, category Article
Eliisa Särkilahti, Terho Valanne. (1990). Induced polyploidy in Betula. Silva Fennica vol. 24 no. 2 article id 5423. https://doi.org/10.14214/sf.a15577

Seeds of ten different Betula species were treated with colchicine solution during germination, to induce duplication of the chromosome set. The species included in the study were B. pendula, B. pubescens, B. papyrifera subcordata, B. papyrifera papyrifera, B. papyrifera occidentalis, B. populifolia, B. alleghaniensis, B.n igra, B. glandulosa and B. nana. The total number of individually labelled, colchicine-treated trees was 1,550. Colchicine treatment induced changes in morphological features, especially in the leaves. These features proved to be good indicators of polyploidization. The experiments produced 687 polyploid trees, 287 of which are still alive. The polyploid Betula trees offer possibilities of studying the significance of the genome dosage for the growth, breeding, adaptability and evolution of Betula.

The PDF includes an abstract in Finnish.

  • Särkilahti, ORCID ID:E-mail:
  • Valanne, ORCID ID:E-mail:
article id 5354, category Article
Jan-Erik Nilsson. (1988). Variation in the rate of winter hardening of one-year-old plus-tree families of Scots pine raised in different enviroments. Silva Fennica vol. 22 no. 3 article id 5354. https://doi.org/10.14214/sf.a15511

The effect of different environmental conditions (four outdoor localities and one greenhouse locality in Northern Sweden) on cold hardening of 29 one-year-old full-sib families from plus-trees of Scots pine (Pinus sylvestris L.) were studied by artificial freeze testing. Plants exposed to low night temperatures during August achieved faster cold hardening than plants raised in milder localities. The family ranking for rate of winter hardening was consistent among outdoor localities if freeze testing was performed at times when plants from different localities had attained similar levels of cold hardiness. However, significant family x locality interactions were obtained when plants from the outdoor localities were freeze tested on the same occasion. Freeze damage was positively correlated with plant height but not correlated with dry matter content in the autumn. Freezing damage of greenhouse raised plus-tree families was uncorrelated with damage of plants raised outdoors. Possible implications for hardiness breeding are suggested.

The PDF includes an abstract in Finnish.

  • Nilsson, ORCID ID:E-mail:
article id 5353, category Article
Øystein Johnsen, Inger Apeland. (1988). Screening early autumn frost hardiness among progenies from Norway spruce seed orchards. Silva Fennica vol. 22 no. 3 article id 5353. https://doi.org/10.14214/sf.a15510

Nursery grown Norway spruce (Picea abies (L.) H. Karst.) seedlings from 12 different seed orchards were tested for early autumn frost hardiness using artificial freezing tests. Seed orchards containing grafted parent clones originating from high altitudes produced seedlings showing higher damage than commercial control seed lots of the commercial controls. A seed orchard containing both German and Norwegian clones produced seedlings showing high damage. The correlation between bud-set and frost damage was high at the provenance level, but lower at the half- and full-sib-levels. Families with good growth capacity in progeny field tests showed large between-family variation in frost damage in the artificial freezing tests. This indicates the possibility to combine high growth rate with acceptable autumn frost hardiness in the selection of parent trees.

The PDF includes an abstract in Finnish.

  • Johnsen, ORCID ID:E-mail:
  • Apeland, ORCID ID:E-mail:
article id 5350, category Article
Heikki Hänninen, Paavo Pelkonen. (1988). Frost hardiness and over-wintering of forest trees. Silva Fennica vol. 22 no. 3 article id 5350. https://doi.org/10.14214/sf.a15507

This issue of Silva Fennica consists of eight articles, which are based on a co-nordic conference ”Frost hardiness and over-wintering in forest tree seedlings”, held in Joensuu, Finland, during December 1–3, 1986. The whole annual cycle of the trees is considered. Emphasis is given on methods for the study of frost hardiness, genetic variation in frost hardiness, nitrogen metabolism, bud dormancy release, and joint effect of natural and anthropogenic stress factors in the winter damage of forest trees. Practical implications for tree breeding and nursery management are discussed.

The PDF includes an abstract in Finnish.

  • Hänninen, ORCID ID:E-mail:
  • Pelkonen, ORCID ID:E-mail:
article id 5342, category Article
Ilari Lumme, Timo Törmälä. (1988). Selection of fast-growing willow (Salix spp.) clones for short-rotation forestry on mined peatlands in northern Finland. Silva Fennica vol. 22 no. 1 article id 5342. https://doi.org/10.14214/sf.a15499

Possibilities of developing suitable willow (Salix spp.) clones for short-rotation forestry on mined peatlands in the north-western area of Finland were studied in a field experiment in which 300 willow clones were tested during 1985–87. Most of the tested clones started to grow from cuttings on limed and fertilized peat soil. Salix viminalis L. clones of southern origin had a higher leafless above ground biomass production than the well adapted control clone and the local Finnish willows, but their winter hardiness was not satisfactory. The growth habit of some southern willows was also better than that of the control clone. It was also possible to select clones with good sprouting capacity. There were few Salix myrsinifolia Calisb. clones of Finnish origin, which had better cold tolerance than all other willows tested and higher biomass production than that of the control clone. The most critical factor to be selected for this is the optimal combination of winter hardiness and biomass production. This is attempted by selecting clones on the basis of this experiment for a breeding program.

The PDF includes a summary in Finnish.

  • Lumme, ORCID ID:E-mail:
  • Törmälä, ORCID ID:E-mail:
article id 5213, category Article
Bo Långström. (1984). Windthrown Scots pines as brood material for Tomicus piniperda and T. minor. Silva Fennica vol. 18 no. 2 article id 5213. https://doi.org/10.14214/sf.a15392

In the 1980 and 1981, windthrown and felled Scots pine (Pinus sylvestris L.) were examined at 8 localities in Sweden. The number and length of egg galleries as well as the number of exit holes of Tomicus piniperda (L.) and T. minor (Hart.) were recorded on sample sections (30 m in length) distributed at 3 m intervals on the 37 fallen pine stems, which were successfully colonized by the beetles. In addition, 78 uprooted pines were surveyed in 6 localities. Most trees were attacked by T. piniperda, but only a few by T. minor. Successful colonization often resulted in the production of several thousand beetles per tree, the maximum being approximately 1,800. The attack density of T. piniperda seldom exceeded 200 egg galleries/m3 bark area, and the brood production usually remained below 1,000 beetles/m3. Much higher figures were obtained or T. minor. In T. piniperda, the rate of reproduction (i.e. the number of exit holes /egg gallery) decreased rapidly with increasing attack density, whereas T. minor seemed to be less sensitive to intraspecific competition.

The PDF includes a summary in Finnish.

  • Långström, ORCID ID:E-mail:
article id 5204, category Article
Pirkko Velling, P. M. A. Tigerstedt. (1984). Harvest index in a progeny test of Scots pine with reference to the model of selection. Silva Fennica vol. 18 no. 1 article id 5204. https://doi.org/10.14214/sf.a15383

Harvest index and number of associated traits were measured in a 16-year-old Scots pine (Pinus sylvestris L.) progeny test based on full-sib families. It was found that harvest index is a highly heritable trait and that a number of yield components are positively correlated with it. It is suggested that harvest index and tree ideotypes should be the basis of selection in cultivated trees. It is emphasized that an integrated approach to tree improvement including silviculture, soil science, industrial and economic constraints and tree breeding is a prerequisite for maximal response.

The PDF includes a summary in Finnish.

  • Velling, ORCID ID:E-mail:
  • Tigerstedt, ORCID ID:E-mail:
article id 5160, category Article
P. M. A. Tigerstedt. (1982). Metsäpuiden populaatiogenetiikka. Helsingissä 1981 pidetyn symposion tutkimusraportit. Silva Fennica vol. 16 no. 2 article id 5160. https://doi.org/10.14214/sf.a15075
English title: Population genetics of forest trees.

The publication comprises proceedings of a conference held in Helsinki in 1981. Forest tree populations are investigated for population genetic structure, mating systems, mechanisms of genetic adaptation and ecological adaptation. Methods and techniques used in population genetic research of forest trees are presented. Much concern is given to applications by means of forest tree breeding, particularly the seed orchard breeding technique. Generally, the application of population genetics in cultivated forests is discussed.

The PDF includes a preface and the presentations of the conference (25 short papers) in English, and a comprehensive summary of the themes of the conference in Finnish.

  • Tigerstedt, ORCID ID:E-mail:
article id 5066, category Article
J. P. Efimov. (1980). Some results on the regularities of seed crops in Scots pine seed orchards. Silva Fennica vol. 14 no. 1 article id 5066. https://doi.org/10.14214/sf.a15007

Establishment of seed orchards to produce genetically improved seed started in the USSR in the 1960’s. The aim is that within 10–15 years the total seed production will reach 50% of the seed used. The paper describes seed production in seed orchards of Scots pine (Pinus sylvestris L.) in the forest-steppe of the European part of the USSR. The orchards have been established either by grafting or by planting of seedlings originating from plus trees. The grafts begin flowering relatively early, however, only at the age of 8–10 years seed crops become relatively regular and abundant. The cone yield in young seed orchards have great variability, and the yield of cones varies between clones. Cone yield does not always correlate with a good seed yield. One of the reasons for high amount of empty seeds is the difference in the periods of flowering between the clones.

The seed crops can be improved by establishing optimal conditions for the growth of the trees. Also, when a seed orchard is founded, the peculiarities of the generative activities of the clones and their reactions to changes in the environmental conditions must be taken account by taking an individual and selective measure approach to improvement measures. The orchards can be established with clones for their genetic combining ability and their requirements for the stimulation of seed-bearing.

The PDF includes a summary in Finnish.

  • Efimov, ORCID ID:E-mail:
article id 5064, category Article
E. P. Prokazin. (1980). Geographic variation in forest trees. Silva Fennica vol. 14 no. 1 article id 5064. https://doi.org/10.14214/sf.a15005

Planting of forest trees takes place in USSR on millions of hectares but without permanent forest seed bases having yet been established in every region of the country. Consequently, local seed does not suffice the need, and it is necessary to secure it from other geographical regions. To avoid negative consequences of seed transfer it is necessary to study geographic variation of the genetic characteristics of forest trees and construct scientifically based division into seed zones. Geographic transfer of seed can also be regarded as a breeding measure. A large research program is being carried out in the USSR on the subject. Most of the existing trials are provenience tests of Scots pine (Pinus sylvestris L.). Over 2,000 hectares of new provenience experiments is to be established in near future.

The PDF includes a summary in Finnish.

  • Prokazin, ORCID ID:E-mail:
article id 5062, category Article
I. Etverk. (1980). Geographical variability of the Norway spruce in the Estonian SSR. Silva Fennica vol. 14 no. 1 article id 5062. https://doi.org/10.14214/sf.a15003

The productivity and several morphological features of Estonian Norway spruce (Picea abies L. Karst.) show significant geographical variation. This is no doubt because of differences in the climatic and soil conditions, which in spite of the small area of the country is quite large. In order to check the possible geographical variability of the gene pool, preliminary experiments were carried out in 1969, when seeds from 93 spruce stands originating from 14 forest enterprises were sowed in a nursery. After two years, the seedlings originating from south-eastern Estonia were the tallest. The seedlings from northern origins were smallest. However, it cannot be maintained that spruces from Southern Estonia are of better genotype than genotype from Northern Estonia since the genotypes are evaluated on the basis of ecological conditions under which the experiments are carried out. Another study suggests that an average shift of 7° to the east of the territory for spruces are suitable for cultivation in Estonia.

The PDF includes a summary in Finnish.

  • Etverk, ORCID ID:E-mail:
article id 5061, category Article
Max Hagman. (1980). Experiences with Norway spruce provenances in Finland. Silva Fennica vol. 14 no. 1 article id 5061. https://doi.org/10.14214/sf.a15002

Ecological investigations have shown that Norway spruce (Picea abies (L.) H. Karst.) reached Western Finland about 1,500–1,000 years B.C. and did not reach Åland islands before around the year 0. The species spread into Finland from the east and north-east, having survived the glaciation somewhere in the central parts of the Asian continent. Geographical variation has provided foresters with provenances of better growth and higher economic yield. In Finland, provenances, for instance, from Austria, Eastern Germany, Romania, Southern Poland and Slovakia have been planted in experiments, mostly in various parts of Southern Finland. According to the results of the experiments, it seems that for the more northern parts of Finland and Sweden the best material was to be obtained from north-east Europe.

The Scandinavian countries decided in 1975 to make a common assessment of all the provenance experiments with Norway spruce. The synthesis confirms the earlier view that provenances from the most north-eastern parts of Central Europe are of the greatest value for Finland.

The PDF includes a summary in Finnish.

  • Hagman, ORCID ID:E-mail:
article id 5061, category Article
Max Hagman. (1980). Experiences with Norway spruce provenances in Finland. Silva Fennica vol. 14 no. 1 article id 5061. https://doi.org/10.14214/sf.a15002

Ecological investigations have shown that Norway spruce (Picea abies (L.) H. Karst.) reached Western Finland about 1,500–1,000 years B.C. and did not reach Åland islands before around the year 0. The species spread into Finland from the east and north-east, having survived the glaciation somewhere in the central parts of the Asian continent. Geographical variation has provided foresters with provenances of better growth and higher economic yield. In Finland, provenances, for instance, from Austria, Eastern Germany, Romania, Southern Poland and Slovakia have been planted in experiments, mostly in various parts of Southern Finland. According to the results of the experiments, it seems that for the more northern parts of Finland and Sweden the best material was to be obtained from north-east Europe.

The Scandinavian countries decided in 1975 to make a common assessment of all the provenance experiments with Norway spruce. The synthesis confirms the earlier view that provenances from the most north-eastern parts of Central Europe are of the greatest value for Finland.

The PDF includes a summary in Finnish.

  • Hagman, ORCID ID:E-mail:
article id 5060, category Article
A. I. Novoselceva. (1980). On the application of forest genetics and forest tree breeding research to practical forest seed production. Silva Fennica vol. 14 no. 1 article id 5060. https://doi.org/10.14214/sf.a15001

The development of the scientific basis for the production of high-quality seed led to the introduction of a large part of the research findings in forest genetics and forest tree breeding into practical forest seed production in the USSR. Since 1971, work has begun in forest enterprises on the establishment of a permanent seed supply for the main tree species – Pinus sylvestris, Picea ssp., Larix ssp. Quercus robur, Haloxylon ssp. and nut trees.

The basis for forest tree improvement is a gene pool which is built up using mass and individual selection of valuable forms in natural populations. In accordance with a long-term programme up to 1990, an inventory of 13.2 million ha of the best high-productive stands has been carried out for breeding purposes in the state forests. About 7,000 ha of plus stands have been selected, and a total of 9,453 ha of seed orchards and 141,253 ha of seed collection stands have been established. The first stage of the programme is planned to be complete in 1980, and in the second stage clonal high-quality seed orchards will be established.

The PDF includes a summary in Finnish

  • Novoselceva, ORCID ID:E-mail:
article id 5058, category Article
Max Hagman. (1980). Suomalais-neuvostoliittolainen metsägenetiikan ja siemenhuollon symposiumi Punkaharjulla 17.–18.8.1978. Silva Fennica vol. 14 no. 1 article id 5058. https://doi.org/10.14214/sf.a14999
English title: Reports of the Finnish-Soviet symposium on forest genetics and forest tree seed production, Punkaharju, Finland, August 17-18. 1978.

As a part of the scientific and technical cooperation between Finland and the USSR a symposium and an excursion on forest genetics and seed production was organized in Finland in August 1978. The symposium paper presented at Punkaharju are published here in order to bring them available for a wider audience.

The 12 symposium reports deal with the following subjects: Practical application of forest genetic research (A.I. Novoselceva), geographical variability and provenance transfer (E.P. Prokazin, M. Hagman, I. Etverk), variation in wood density (P. Velling), variation of flowering and seed crops in seed orchards (Y.P. Efimov), and natural stands (V. Koski), vegetative propagation (J. Niiranen), seed size effects and early test problems (J. Mikola), quantitative analysis of genotypic and environmental effects (S.A. Petrov), hormonal induction of flowering (O. Luukkanen) and x-ray photography analysis of the ageing of seeds during storage (M. Ryynänen).

The PDF includes a summary in Finnish.

  • Hagman, ORCID ID:E-mail:
article id 4930, category Article
Tapio Lehtiniemi. (1976). Ionisoivan säteilyn vaikutus varastokuivien ja liotettujen metsäpuiden siementen idäntään ja taimien alkukehitykseen. Silva Fennica vol. 10 no. 1 article id 4930. https://doi.org/10.14214/sf.a14772
English title: Effect of ionizing radiation on the germination of storage-dry and soaked forest tree seeds and on the initial development of seedlings.

The study was carried out in order to find out the changes taking place in germination of seeds in certain tree species as a function of gamma irradiation, the height growth of the seedlings produced and the types of phenotypic mutants possibly found in the generation that had received radiation. The tree species studied were Pinus sylvestris L., Picea abies (L.) H. Karst., Betula verrucosa (Betula pendula Roth), B. Pubescens Ehrh., Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench.

Soaked seeds that had received a rather small dose of radiation germinated usually better than storage-dry seeds, B. pubescens being an exception. The damages observed in germination, height growth and the relative number of mutants were greater the higher the irradiation doses. The LD50 dose (germination, 28 days) was as follows in the case of the different tree species (storage dry/soaked): P. Sylvestris 1,500-2,000/2500-3,000, P. abies 1,000-1,500/4,000-4,500, B. pendula 9,500-10,000/7,000-7,500, B. pubescens >10,000/7,500-8,000 and A. Glutinosa 10,000/8,500-9,000 rad. Mass production of different mutants of deciduous trees for ornamental purposes, for example, appears to be easy using gamma-irradiation. On the other hand, the possibility of increasing tree growth remains open for further study.

The PDF includes a summary in English.

  • Lehtiniemi, ORCID ID:E-mail:
article id 4897, category Article
A. V. Chudnyi. (1974). Metsäpuiden populaatiorakenteen tutkimusmenetelmistä. Silva Fennica vol. 8 no. 1 article id 4897. https://doi.org/10.14214/sf.a14741
English title: Investigation methods in forest tree population studies.

From the tree breeder’s point of view, an investigation of the chemical compounds in a tree population is worthwhile, if sufficiently high correlations exist between the chemical composition and any economical important characteristics. In Scots pine (Pinus sylvestris L.) populations, such a correlation seems to exist between a high α-pinene and a low Δ3-carene content on the one hand, and the poor resistance to Fomitopsis annosa Fr. (now Heterobasidion annosum (Fr.) Bref.) but a rapid development during the first half of the life cycle on the other hand. Detailed investigation on the terpene contents in pine populations were conducted at 121 locations throughout the Soviet Union. As a result, the range of this species was divided into zones, each of which was characterized by a distinct terpene composition pattern. In continuing selection and breeding work, the terpene contents are being used as indicators when the variation of economically important characteristics of Scots pine populations is studied.

The PDF includes a summary in English.

  • Chudnyi, ORCID ID:E-mail:
article id 4888, category Article
Olavi Luukkanen. (1973). Havaintoja kuusen vapaapölytysjälkeläistöjen ja männyn metsikköalkuperien CO2-aineenvaihdunnasta. Silva Fennica vol. 7 no. 4 article id 4888. https://doi.org/10.14214/sf.a14726
English title: Observations on CO2 exchange in open pollinated progenies of Norway spruce and provenances of Scots pine.

Photosynthesis and dark respiration in five families of autochtonous Norway spruce (Picea abies (L.) H. Karst.) and in seedlings from twenty Finnish stands of Scots pine (Pinus sylvestris L.) were investigated in constant environmental conditions. Values of CO2 exchange were compared with the height growth and weight of seedlings in Norway spruce and with the weight alone in Scots pine. No statistically significant differences were found in CO2 exchange among progenies or stands. Photosynthetic efficiency and photosynthetic capacity showed a positive correlation both in spruce and in pine. Growth and net photosynthetic capacity were linearly and positively correlated in pine. Spruce and a higher light compensation point than pine. The use of an open IRGA system with several simultaneous measurements and the trap-type cuvette construction in genetic work are discussed.

The PDF includes a summary in English.

  • Luukkanen, ORCID ID:E-mail:
article id 4869, category Article
Ole Oskarsson, P. M. A. Tigerstedt. (1972). Metsänjalostuksen mahdollisuudet II. Silva Fennica vol. 6 no. 3 article id 4869. https://doi.org/10.14214/sf.a14672
English title: The possibilities in forest tree breeding II. Selection differences and genetic gains in selected seed stands of Scots pine.

The aim of this study was to estimate the genetic gain of volume growth in Scots pine (Pinus sylvestris L.) selected seed stands. To obtain highest possible accuracy, the estimations are based on a large statistical material comprising 197 separate seed stands. It is concluded that the genetic gain of volume growth ranges between 7.4–15.0%. Unwanted pollen contaminations may, however, in the worst case halve this genetic gain.

The PDF includes a summary in English.

  • Oskarsson, ORCID ID:E-mail:
  • Tigerstedt, ORCID ID:E-mail:
article id 4833, category Article
Eero Malmivaara, Jouni Mikola, Christel Palmberg. (1971). Pajujen mahdollisuudet metsäpuiden jalostuksessa. Silva Fennica vol. 5 no. 1 article id 4833. https://doi.org/10.14214/sf.a14622
English title: Potential of willows in forest tree breeding.
Original keywords: metsänjalostus; pajut; Suomi

A review is made into the experiences and possibilities of willow breeding, with a particular consideration of their application under Finnish conditions.

In comparison with other tree genera, Salix has many advantages in breeding. The great number of species, large genetic variation between and within species and frequent crossability offer good possibilities for improvement by hybridization. The dioecious flowering, plentiful seed production and short generation cycle are valuable properties for breeding by controlled pollination. Individuals with desirable characteristics can be easily propagated vegetatively from cuttings. The propertied stated above are also characteristic of poplars, the breeding of which has resulted in great success. Corresponding results can be therefore expected from willow breeding, which has recently been initiated in several countries.

Today willows have no practical significance for forestry in Finland. There are, however, some suitable Salix species, both indigenous and exotic, for starting material for breeding, and plenty of favourable sites for willows. Therefore, the beginning of breeding research with willows should be well justified also in Finland.

The PDF includes a summary in English.

  • Malmivaara, ORCID ID:E-mail:
  • Mikola, ORCID ID:E-mail:
  • Palmberg, ORCID ID:E-mail:
article id 4831, category Article
Lauri Mikkola. (1970). Kuusilajien risteytyvyydestä. Silva Fennica vol. 4 no. 4 article id 4831. https://doi.org/10.14214/sf.a14620
English title: On the crossability of Picea species.

Seed development was microscopically studied after controlled pollinations. In all the interspecific crosses incompatibility occured. In the following crosses the growth of all the pollen tubes stopped before they had penetrated through the nuclear cap: Picea abies (L.) Karst. x mariana, abies x jezoensis (and the reciprocal), abies x omorika (and the reciprocal), mariana x asperata, mariana x jezoensis and Picea abies x Pinus sylvestris L.

Some of the eggs were fertilized in the crosses Picea abies x glauca (and the reciprocal) abies x asperata, abies x koyamai, abies x obovata, mariana x omorika and jezoensis x omorika. Embryo degeneration was observed in all these crosses. All the embryos died in the crosses abies x glauca (and the reciprocal) as well as jezoensis x omorika. Adequate amounts of full seed for germination test was obtained from the crosses abies x asperata, abies x koyamai and abies x obovata. In all these crosses there were seeds which were able to germinate and the hybrids are now one growth season old.

The PDF includes a summary in English.

  • Mikkola, ORCID ID:E-mail:
article id 4831, category Article
Lauri Mikkola. (1970). Kuusilajien risteytyvyydestä. Silva Fennica vol. 4 no. 4 article id 4831. https://doi.org/10.14214/sf.a14620
English title: On the crossability of Picea species.

Seed development was microscopically studied after controlled pollinations. In all the interspecific crosses incompatibility occured. In the following crosses the growth of all the pollen tubes stopped before they had penetrated through the nuclear cap: Picea abies (L.) Karst. x mariana, abies x jezoensis (and the reciprocal), abies x omorika (and the reciprocal), mariana x asperata, mariana x jezoensis and Picea abies x Pinus sylvestris L.

Some of the eggs were fertilized in the crosses Picea abies x glauca (and the reciprocal) abies x asperata, abies x koyamai, abies x obovata, mariana x omorika and jezoensis x omorika. Embryo degeneration was observed in all these crosses. All the embryos died in the crosses abies x glauca (and the reciprocal) as well as jezoensis x omorika. Adequate amounts of full seed for germination test was obtained from the crosses abies x asperata, abies x koyamai and abies x obovata. In all these crosses there were seeds which were able to germinate and the hybrids are now one growth season old.

The PDF includes a summary in English.

  • Mikkola, ORCID ID:E-mail:
article id 4823, category Article
Christel Palmberg. (1970). Heritabiliteetin arvioiminen eräässä männyn (Pinus silvestris L.) jälkeläiskokeessa. Silva Fennica vol. 4 no. 3 article id 4823. https://doi.org/10.14214/sf.a14612
English title: Estimation of heritability in open-pollinated plus tree progenies of Pinus sylvestris L.

Field experiments of Scots pine (Pinus sylvestris L.) was established by planting seedlings grown from seeds collected from open-pollinated plus trees throughout the country. The 36 progenies represented were planted in 4 blocks as 2+2 transplants in 1960. The main characteristics of the seedlings were measured in 1966 and 1968. Considerable damage had been caused to the stands by moose (Alces alces) and Melampsora pinitorqua Rostr., consequently, therefore, only normally developed seedlings were measured.

Highly significant differences between progenies were found in the number of branches in 1968 and in the ratio of height of tree to the length of the longest branch. In 1968, the differences in height between progenies were not significant, but there were significant differences between blocks both in tree height and length of terminal shoot. Obviously, the edaphic heterogeneity of the site has influenced mainly the juvenile growth of the plants, because in the length of the terminal shoot there could be seen also significant differences between the progenies. There were no significant differences between the progenies in the length of the longest branch, in the angles of the thickest branches, in stem taper and in the diameter of the thickest branch.

The PDF includes a summary in English.

  • Palmberg, ORCID ID:E-mail:
article id 4816, category Article
P. M. A. Tigerstedt, Eero Malmivaara. (1970). Metsänjalostuksen mahdollisuudet I.Pluspuiden valintaero ja siemenviljelysten valintahyöty. Silva Fennica vol. 4 no. 2 article id 4816. https://doi.org/10.14214/sf.a14605
English title: The possibilities in forest tree breeding. I Selection differential of plus trees and genetic gain in seed orchards in Finland.

An attempt was made to estimate critically the genetic gain in clonal seed orchards of Scots pine (Pinus sylvestris L.) in Finland. The selection differential of Scots pine and Norway spruce (Picea abies (L.) H. Karst.) is calculated on the basis of filed information on selected plus trees which has been kept by the genetic register at the Finnish Forest Research Institute. The differentials were computed as realized differences in height between plus-trees and normal stand characteristics on respectively site class and as a function of age.

The genetic gain in height growth of Pinus sylvestris was computed on the basis of information on selection differential and heritability. This genetic gain is between 2.6–4.4% provided there is no pollen contamination from unknown sources outside the seed orchard. The genetic gain of volume growth in Scots pine is about 7–15%, provided there is no pollen contamination in the seed orchard. However, according to investigations, there is invariably some pollen contamination in this kind of seed orchards. The contamination decreases to about 30–50% as the orchard matures and starts to produce endemic pollen. If the pollination would be entirely due to foreign pollen sources, the mathematically calculated genetic gain would be 3.5–7.5%.

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  • Tigerstedt, ORCID ID:E-mail:
  • Malmivaara, ORCID ID:E-mail:
article id 4753, category Article
Helge Johnsson. (1967). Olika vägar för rasmässig förbättring av vårt skogsodlingsmaterial. Silva Fennica vol. 1 no. 3 article id 4753. https://doi.org/10.14214/sf.a14537
English title: Different ways of genetic improvement of forest trees in Scandinavia.

Transfer of southern provenances of trees to the north leads to an increased growth until the limit of hardiness is exceeded, which may be utilized in practical forestry. Selection from certain local provenances are important both for the immediate supply of seed and on a somewhat longer view. A certain degree of improvement can be achieved by avoiding minus regions and concentrating seed collection on better areas. Also, seeds can be collected from the best stands only, and by accepting only seed from the best trees of such stands. The selection can be strengthened considerably by production of seed orchards. The seed production is based on a small number of trees of particular superiority that are reproduced vegetatively. The clones are planted in an orchard, which pollinate each other.

Hybridization of two different provenances might result in an increased capacity of production. Such hybridized seed can be produced in orchards established, for instance, as a combination of selection and hybridization orchards. As regards the major Scandinavian tree species there are only small prospects of advancement through species hybridization. The method available at present for efficient racial improvement of our forest trees is individual selection in connection with seed production in orchards. In special cases, however, other methods such as transfer of provenances, provenance hybridization, species hybridization, and polyploidization will result in considerable progress.

The PDF includes a summary in English.

  • Johnsson, ORCID ID:E-mail:
article id 4753, category Article
Helge Johnsson. (1967). Olika vägar för rasmässig förbättring av vårt skogsodlingsmaterial. Silva Fennica vol. 1 no. 3 article id 4753. https://doi.org/10.14214/sf.a14537
English title: Different ways of genetic improvement of forest trees in Scandinavia.

Transfer of southern provenances of trees to the north leads to an increased growth until the limit of hardiness is exceeded, which may be utilized in practical forestry. Selection from certain local provenances are important both for the immediate supply of seed and on a somewhat longer view. A certain degree of improvement can be achieved by avoiding minus regions and concentrating seed collection on better areas. Also, seeds can be collected from the best stands only, and by accepting only seed from the best trees of such stands. The selection can be strengthened considerably by production of seed orchards. The seed production is based on a small number of trees of particular superiority that are reproduced vegetatively. The clones are planted in an orchard, which pollinate each other.

Hybridization of two different provenances might result in an increased capacity of production. Such hybridized seed can be produced in orchards established, for instance, as a combination of selection and hybridization orchards. As regards the major Scandinavian tree species there are only small prospects of advancement through species hybridization. The method available at present for efficient racial improvement of our forest trees is individual selection in connection with seed production in orchards. In special cases, however, other methods such as transfer of provenances, provenance hybridization, species hybridization, and polyploidization will result in considerable progress.

The PDF includes a summary in English.

  • Johnsson, ORCID ID:E-mail:
article id 7657, category Article
Matti Rousi. (1990). Breeding forest trees for resistance to mammalian herbivores - a study based on European white birch. Acta Forestalia Fennica no. 210 article id 7657. https://doi.org/10.14214/aff.7657

Resistance to browsing by mammals differs among birch species, and among origins and families of European white birch (Betula pendula Roth). The variation in resistance is large even among individual seedlings of the same family.

On the surface of the bark of European white birch seedlings there are resin droplets, and the number of droplets is strongly and positively correlated with resistance to browsing by hares. The resistance of European white birch apparently is not expensive metabolically because the rapid growth rate of seedlings was positively correlated with hare resistance, and no correlation was found between seedling size and vole resistance. In cafeteria experiments voles and hares were very discriminating in their feeding on birch seedlings. In field experiments, however, environmental heterogeneity partly masked differences in vole resistance among birch families. Fertilization of seedlings seems not to have a clear effect on resistance to hares. On the other hand, there were indications that greenhouse temperature had an effect on resistance to voles. Practical forestry applications of differences in resistance, e.g. use of species hybrids and clonal forestry, are discussed. The prospects for resistance breeding are good.

The PDF includes a summary in Finnish.

  • Rousi, ORCID ID:E-mail:
article id 7620, category Article
Min-Sup Chung. (1981). Biochemical methods for determining population structure in Pinus sylvestris L. Acta Forestalia Fennica no. 173 article id 7620. https://doi.org/10.14214/aff.7620

Studies on Finnish Scots pine (Pinus sylvestris L.) plus tree clones by monoterpene and isozyme analyses was undertaken to further investigate mating system, population structure and pollination. Six allozyme systems (3 GOT, 1 GDH and 2 LAP) were properly analysed on the basis of segregation. Monoterpenes were analysed from needle material and segregation in high and low 3-carene content was found to depend on two alleles C and c. Thus, six allozyme systems and one monoterpene system were used as markers in this study.

It was shown that the northern clonal group maintains a much genetic variation as the central or southern clonal groups. The conditional probability of self-fertilization in about 20-year old clones estimated by the multilocus model was 14.1%, of which 8% originate from mating between trees that carry the same alleles to one of the maternal parent at some loci and 6% through self-fertilization.

There was no prominent difference in allele frequency of male gametes that pollinated the very early or very late flowering clones. The northern clonal group has higher a lower frequency of alleles GOT B2 and B3 respectively than of the southern clonal groups. The artificial plus tree selection, particularly in northern Finland, appears to favour heterozygous genotypes for the alleles that control 3-carene content n Scots pine.

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  • Chung, ORCID ID:E-mail:
article id 7568, category Article
Kim von Weissenberg. (1973). Indirect selection for resistance to fusiform rust in Loblolly pine. Acta Forestalia Fennica no. 134 article id 7568. https://doi.org/10.14214/aff.7568

Indirect selection for resistance is superior to direct selection under certain conditions. The phenotypic correlation was studied between resistance to fusiform rust (Cronartium fusiforme) in loblolly pines (Pinus taeda L.), chosen by a newly-developed stability index, and the amount of resin acids, growth-inhibiting substances, and fatty acids extracted from pine tissue. No association was found between rust resistance and the amount of total or individual resin acids in clones or families. The amount of growth-inhibiting substances present in branches from full-sib families was greater in rust-resistant compared to rust-susceptible families. A strong association was found between resistance and the amount of long-chain fatty acids in four clones. A weak association was found between resistance and the amount of the fatty acid 18:2 in five other clones.

The PDF includes a summary in Finnish.

  • Weissenberg, ORCID ID:E-mail:
article id 4638, category Article
Risto Sarvas. (1953). Ohjeita pluspuiden valitsemista ja ilmoittamista varten. Silva Fennica no. 80 article id 4638. https://doi.org/10.14214/sf.a14054
English title: Instruction for the selection and registration of plus trees.

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes principles of breeding of forest trees and the selection of fast growing, healthy and qualitatively good trees, named plus trees, for seed production in Finland.

  • Sarvas, ORCID ID:E-mail:
article id 4586, category Article
Risto Sarvas. (1948). Metsäpuiden rodunjalostuksesta. Silva Fennica no. 64 article id 4586. https://doi.org/10.14214/sf.a13988
English title: Forest tree breeding.

Silva Fennica Issue 64 includes presentations held in the third professional development courses, arranged for foresters working in the public administration in 1947. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation introduces the aims and work of Foundation of Forest Tree Breeding, established in 1946.

  • Sarvas, ORCID ID:E-mail:
article id 4586, category Article
Risto Sarvas. (1948). Metsäpuiden rodunjalostuksesta. Silva Fennica no. 64 article id 4586. https://doi.org/10.14214/sf.a13988
English title: Forest tree breeding.

Silva Fennica Issue 64 includes presentations held in the third professional development courses, arranged for foresters working in the public administration in 1947. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation introduces the aims and work of Foundation of Forest Tree Breeding, established in 1946.

  • Sarvas, ORCID ID:E-mail:

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