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Tore Skrøppa

Research Professor (OAP Agreement)

NIBIO Publications
NIBIO Projects

Division of Forest and Forest Resources

Forest Genetics and Regeneration

(+47) 930 07 710
tore.skroppa@nibio.no

Place
Ås H8

Visiting address
Høgskoleveien 8, 1433 Ås

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Authors

Thomas Solvin Tore Skrøppa Arne Steffenrem

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No abstract has been registered

Authors

Tore Skrøppa

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No abstract has been registered

Authors

Arne Steffenrem Thomas Solvin Tore Skrøppa

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No abstract has been registered

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Authors

Tore Skrøppa Thomas Solvin Arne Steffenrem

Abstract

The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in Norway. Nursery trials were performed with the families from these crosses and families from seeds collected from open pollination. Traits measured and analysed are seed weight, germination rate, germination percentage, terminal bud set, and seedling heights the first and second years. The seedlings from the population at origin 500 m had lower seed weight, lower heights and earlier bud set than those from the two populations from lower altitude. A considerable variation was present among families within each diallel, and the GCA variance components had the highest values and were significant for most traits. Variance components for SCA and maternal effects were also significant for some traits, but with inconsistent values in the three diallels. A strong relationship was present between the weight of the seed lots from the maternal parent and mean family height after one and two growing seasons. The highest estimate of heritability was observed for bud set, with similar values in all three diallels.

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Authors

Tore Skrøppa Thomas Solvin Arne Steffenrem

Abstract

The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in southern Norway. Seedlings from families from the diallels and open pollinations were tested in short-term tests on agricultural soil at one site at altitude 85 m until age 10 years from seed. Tree height at ages 7 and 10 years and diameter at age 10 had strongly significant GCA variance components within each population. The components for SCA and maternal effects were small and not significant, indicating low levels of non-additive genetic variation. For the days of initiation and cessation of the shoot elongation period the GCA components were dominating and had the highest heritability estimates in two of the diallels. Estimates of genetic correlations between traits measured in earlier nursery trials and height and diameter in the short-term trials had low and not consistent values in the three diallels. The duration of the shoot growth period and rate of growth showed positive relationships with height and diameter. Strong relationships were present between half-sib family means from the diallels and open-pollinated families for height, diameter and phenology traits. Progeny trials testing open-pollinated half-sib families from natural populations can be used for selection of candidates for the initial breeding populations.

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Authors

Tore Skrøppa Arne Steffenrem Gunnar Haug

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Field trials with Norway spruce seedlings from 84 full-sib families from a factorial cross in Opsahl Seed Orchard and 11 provenances were planted at eight sites between altitudes between 600 and 900 m in Oppland County in Norway. Measurements of tree heights and assessments of stem and branch defects were made at regular intervals until 34 years from seed. Data from measurements made in nursery trials and from artificial freezing trials were also available. The families from the seed orchard had on average 12 % better height growth than the provenances. For volume growth per hectare, measured in two of the trials 30 years after planting, the families had a superiority of more than 30 %. A large variation among families was present for height growth and additive genetic variation was the main genetic factor. For the maternal half-sib families, the ranking of families for height was stable after 15 years from seed, and the five best families selected for height at that age were at age 34 years 6 % taller and produced 13 % more volume per hectare compared with the mean of all families. Weak relationships were present between traits measured in the nursery trial, the freezing test and the field trials. Assessments were made of cone production at age 20 years after planting and showed variation among families for the frequency of trees with cones.

Authors

Arne Steffenrem Thomas Solvin Tore Skrøppa

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Authors

Tore Skrøppa Øystein Johnsen Arne Steffenrem

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Artificial freezing tests were performed on seedlings from Norway spruce families at the end of the first growing season. Similar tests were made on twigs collected from trees in a progeny test at the end of growing season nine. The 26 families in the early test were included in the short-term progeny test with 100 full-sib families from a 10 x 10 factorial cross. All families were also planted in seven field trials in Norway, Sweden and Finland, from which data on mortality, tree heights and stem damage at age 10 years are available. Significant difference was found among families for freezing test injuries on whole intact seedlings at the end of the first growing season and for lethal temperature of needles on detached twigs collected at the end of growing season nine. However, no relationships were found between the freezing test scores of families in the two types of tests or few between these scores and the traits measured in the short-term and field trials. The results show that frost hardiness testing of families at a young age, grown under artificial temperature and light conditions in nursery, is a weak predictor of their performance under natural conditions in field at older ages.

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Authors

Tore Skrøppa

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Short-term trials on cultivated soil were planted with families of Norway spruce that had shown epigenetic memory effects in early tests up to age two years. Measurements and assessments were made of phenology traits, tree heights and stem defects until age 16 years in these trials. The memory effects of the temperature conditions during embryo development and seed maturation were confirmed for the timing of bud flush and for start and cessation of shoot elongation at age six years. The mean differences in timing of these events caused by temperature treatments were on average less than two days. They were considerably larger for families with strong effects on terminal bud set at the end of the first growing season. The memory effects did not result in a prolonged shoot growth period, nor did they affect height growth. Interaction effects expressed in adaptive traits between factorial treatments of temperature and daylength during seed production were large in the short-term trial and were still present at age nine years. The results presented demonstrate that strong memory effects observed in early tests may also be expressed in phenology traits for at least the next five growing seasons.

Authors

Arne Steffenrem Thomas Solvin Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa Arne Steffenrem

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Norway spruce parents selected from results in progeny trials for testing Svenneby Seed Orchard clones were crossed in a factorial crossing design, and full-sib families were planted in short-term and field trials in southern Norway. Artificial freezing tests with the same families were made the first growing season and at ages 10 and 12 years. Offspring of parents selected for superior growth were taller in the field tests than those from parents with heights lower than the mean in the progeny test. However, the correlations between half-sib family performance in the initial progeny test and in the offspring field tests were only moderate. The variation among families in injury scores in the freezing tests was large, but the relationships with field trial performance were weak, indicating that frost hardiness testing at a young age is not valuable for predicting later field performance. Families with a late timing of bud flush had the highest frequency of injuries after a frost event at mid-summer. These families were also the tallest in the field tests. The families from crosses among Svenneby Seed Orchard clones had better height growth than commercial provenances. Foreldretrær av gran, valgt ut fra resultater i avkomforsøk for å teste kloner i Svenneby frøplantasje, ble krysset etter en faktoriell krysningsplan, og full-søsken familiene ble plantet i kortidsforsøk og i langsiktige feltforsøk. Fryseforsøk med familiene ble gjort etter første vekstsesong og ved alder 10 og 12 år. Avkom fra foreldre valgt ut for god høydevekst var høyere i feltforsøkene enn de fra foreldre som ble valgt ut med midlere høyde. Det var bare moderate korrelasjoner mellom høyder til halv-søsken i de første avkomforsøkene og i feltforsøkene. Det var betydelig variasjon mellom familiene i skader etter frysforsøkene, men sammenhengene var svake mellom frostskader og vekst og skader i feltforsøkene. Dette indikerer at resultater fra testing av frostherdighet i ung alder sier lite om hvordan trær fra familiene senere vokser i felt. Familier med sen skuddskyting fikk mest skader etter frostnetter 22.-23. juni. De sent skytende familiene hadde best høydevekst i feltforsøkene. Trærne fra familiene fra Svenneby frøplantasje var høyere enn de fra hadde handelsprovenienser.

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Authors

Inge Dox Tore Skrøppa Mieke Decoster Peter Prislan Aina Gascó Jožica Gričar Holger Lange Matteo Campioli

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Historically, the autumn dynamics of deciduous forest trees have not been investigated in detail. However, autumn phenological events, like onset of loss of canopy greenness (OLCG), onset of foliar senescence (OFS) and cessation of wood growth (CWG), have an important impact on tree radial growth and the entire ecosystem's seasonal dynamics. Here, we monitored the leaf and wood phenological events of silver birch (Betula pendula) at four different sites in Ås, southeastern Norway: (a) a natural mature stand, (b) a plantation on former agricultural ground, (c) young natural trees, and (d) young trees in pots under different fertilization levels. The study took place over four consecutive years (from 2017 to 2020), with a particular focus on 2018, a year in which there was a severe summer drought, and the next year, 2019, which featured more normal conditions. First, we provided a description of birch phenology within its mid-north distributional. Second, we showed that drought advanced CWG by about 5 to 6 weeks and it delayed OLCG and OFS up to 30 days. Third, we observed an unexpected advance in OLCG in 2019 compared to 2018 (30 days) and 2020 (14 days). OFS presented similar dynamics as OLCG, whereas CWG was advanced only in 2018. These findings might indicate lag-effects of severe drought on the next year autumn leaf phenology but not on wood growth. On the other hand, the comparison between the natural stand and the plantation showed that, under drought conditions, wood growth is more sensitive to site fertility than autumn leaf phenology. In summary, our study elucidated the autumn dynamics of an important deciduous forest species in the northern temperate zone and showed unexpected impacts of a severely dry and warm summer on the current and next year leaf phenology.

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Tore Skrøppa

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Denne rapporten presenterer resultater fra forsøk med populasjoner fra Sør-Norge og Trøndelag og med provenienser fra Mellom-Europa og Finland. Både korttidsforsøk plantet på jordbruksmark og feltforsøk i skogen ble plantet. Målinger og registreringer ble gjort av høyde, tidlighet og høstskudd. Det var signifikante forskjeller i disse egenskapene både mellom provenienser, norske populasjoner og familier innen populasjoner. For de norske populasjonene var det samspill for middeltall av høyde og tidlighet i korttids- og feltforsøkene. Betydelige samspill for overlevelse og høyde ble funnet mellom provenienser og lokaliteter for feltforsøk som bare ligger noen få kilometer fra hverandre. Disse samspillene kom sannsynligvis på grunn av forskjeller i det lokale temperaturklimaet. Kunnskap om samspill og om de avhenger av geografiske og klimatiske faktorer, er viktig både for valg av provenienser og for planteforedlingen for gran.

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Tore Skrøppa Arne Steffenrem

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Genetic variation and phenotypic stability in Norway spruce were studied based on provenances, families, and clones planted in trials at 12 sites in four Nordic countries. The families were generated in a factorial cross between 10 parents of Norwegian origin and 10 parents of Eastern European origin, and the clones were propagated from seedlings within 20 of the same families. Traits analyzed were survival, proportion of trees with stem defects, and tree heights. Stability was analyzed by regression analyses with the genetic entries’ annual shoot increment as the dependent variable and the total site mean as an environmental index. Information about growth and phenology traits were available from short-term tests. For tree heights, significant variance components were present both among female and male parents, but not for their interactions, indicating that non-additive genetic effects are small. Genotype × environment interactions were significant at all three genetic levels, but their variance components had considerably lower values than the variance components estimated for the effects of families and clones. For the set of families of Norwegian origin, strong relationships were observed between the timing of annual shot elongation, mortality, and height growth. Large variation was found at all three genetic levels for phenotypic stability measured by regression coefficients. A positive relationship was present between the regression coefficient and the timing of annual shoot growth for families, indicating that later flushing families responded more to a high site index. The regression coefficient can be a useful supplement to the breeding value when selecting for superior and stable genotypes.

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Tore Skrøppa Arne Steffenrem

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Tore Skrøppa

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Tore Skrøppa Ragnar Johnskås Gunnar Haug

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Controlled crosses were made on clones in a seed orchard and the pollination bags were kept on the branches until the cones were harvested. Cones after open pollination were collected at the same time. Seedlings from the controlled pollinations, from open pollination of the same maternal parent and from commercial provenances were grown in growth chambers and terminal bud set was recorded after short day treatments. The seedlings from the seeds of cones that were kept in the pollination bags had a significantly later bud set then expected based on comparisons with their half-sibs from open pollination. The difference corresponds to a decrease in altitude of 100 m at provenance level. It can be caused by epigenetic effects due to temperature differences inside and outside the bags during seed maturation.

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Kjersti Bakkebø Fjellstad Tore Skrøppa

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Skog er viktig i Norge. Det er uttalt politisk vilje til å styrke skogens bidrag for økonomisk verdiskaping i landbruket og for å nå viktige mål knyttet til energi, klima, miljøverdier og økosystemtjenester. Skogressursene er viktige for å opprettholde et bærekraftig landbruk og matproduksjon over hele landet, ettersom inntekt fra skogen bidrar til den totale inntekten for mange aktive bønder. Skogene er også viktige for rekreasjon og for folkehelsa. Skogtregenetiske ressurser i Norge brukes i produksjonsskogbruk, til skogplanting etter hogst og på annet areal, eller til treslagsskifte. De brukes også til juletreproduksjon, til landskapsformål eller i parker og hager....

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Tore Skrøppa Arne Steffenrem

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Seedlings from seeds collected in three natural populations of Norway spruce (Picea abies (L. Karst)) in each of 21 provenances distributed between latitudes 63ºN to 66º20’N and altitudes from 25 to 500 m in Trøndelag og Nordland counties were tested in nursery trials and one long-term field trial. Large provenance variation was found for phenology traits and early height growth in the nursery trials. A strong clinal variation was found for these traits relative to latitude and altitude. These relationships were weaker for height and diameter at ages 26 and 40 years. The timing of bud flush was strongly related to the temperature conditions at the seed collection sites, whilst terminal bud set and lammas shoot percentages showed high correlation coefficients with the provenance latitude. Provenances in the same geographic region showed large differences in height and diameter Growth in the field trial. The long-term experimental site Spelrem is situated within the northern Natural range of Norway spruce and the general trend in this material is that provenances from the Northern part of the range perform better compared with provenances from more southern areas. Hence, the gain from provenance transfer seems to be limited under the present climatic conditions in this region.

Authors

Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Thomas Solvin

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A complete diallel cross was made among nine Betula pendula trees growing in a natural population and a trial was planted on agricultural soil at one site. This exceptional trial has provided estimates of genetic parameters that can only be estimated in complete diallels. Traits measured were height and diameter during a period of 37 years, and assessments were made of bud burst, leaf abscission and rust infection at the early ages. All traits showed genetic variation and the variance components of general combining ability (GCA) effects were dominating, with heritability estimates of 0.16 and 0.23 for height and diameter at age six years. The best-growing families could be identified at that age. At age 37 years, when the trial had been thinned twice, the offspring from the highest and lowest ranked parent for growth contributed with 19% and 6% of the total volume of the stand, respectively. The GCA effects were also highly significant for the assessment traits, but with an interaction with year for bud burst. High values of estimates of genetic correlations proved that bud burst, leaf abscission and rust infection are interrelated, and also to some extent with growth traits. Families with an early bud burst were tallest, were less affected by the rust fungus and kept their leaves later in the autumn.

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Tore Skrøppa Arne Steffenrem

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Tore Skrøppa

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Thomas Solvin Arne Steffenrem Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Fulvio Ducci Tore Skrøppa

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Tore Skrøppa Kjersti Bakkebø Fjellstad

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Forests and wooded land cover 39% of the land area of Norway, with two conifer species, Picea abies and Pinus sylvestris, dominating the forest area. Twenty-five of 35 native forest tree species have their northern limit in this country. The genetic resources of 18 species are considered to be vulnerable or threatened either at a local or national level. Genetic information is available for 13 of the native species, with Picea abies being the species that has been most thoroughly characterised. The National Programme for Forest Genetic Resources is administered by the Norwegian Genetic Resource Centre. This programme covers four major areas: generating knowledge and monitoring processes influencing genetic resources; in situ and ex situ conservation activities; sustainable use and development of forest genetic resources; and networking, coordination and dissemination of knowledge. In situ conservation of genetic resources of forest tree species is carried out in nature reserves. Twenty-three gene conservation units, covering ten species, have been established in such reserves. Ex situ conservation of forest genetic resources is achieved through collections in arboreta and botanical gardens and in the long-term field plantations of research and breeding programmes. In addition, seed samples of selected forest tree species are stored at Svalbard Global Seed Vault. Forests in Norway are regenerated both by natural and artificial means. A revised tree breeding strategy, with emphasis on Picea abies, has been developed to improve climatic adaptation, growth and quality, without decreasing the genetic diversity in future forests or the potential for adaptation to future climatic conditions.

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Milan Lstibůrek Yousri A. El-Kassaby Tore Skrøppa Gary R. Hodge Jørn Henrik Sønstebø Arne Steffenrem

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Tore Skrøppa

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Tore Skrøppa

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Thomas Solvin Arne Steffenrem Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Arne Steffenrem Thomas Solvin

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Arne Steffenrem Halvor Solheim Tore Skrøppa

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The root rot pathogens in Norway spruce (Picea abies) Heterobasidion ssp. cause substantial loss in carbon sequestered in forest and economic revenue for forest owners. To facilitate strategic breeding planning for increased resistance against this pathogen in particular, the blue stain fungus Endoconidiophora polonica, growth and wood quality traits (wood density and spiral grain), we estimated additive genetic parameters, correlations and the potential response from selection. Parameters were estimated from a progeny trial series established at two sites (25 years from planting) and their parents in a seed orchard (43 years from grafting). A standard half-sib analysis based on progenies and a parent–offspring regression was used for estimation of heritabilities. Resistance against the pathogens was measured as lesion length under bark after inoculations in phloem. Heritability values varied with site and estimation procedure from 0.06 to 0.33, whereas the phenotypic variance (as CV P ) is high and fairly stable around 40–50 %. Heritability values for wood density and spiral grain in the same material varied from 0.32 to 0.63. The highest heritability values were generally obtained from parent–offspring regression. There is no evidence of resistance traits being genetically correlated with growth or wood quality traits. Wood density is negatively correlated with stem diameter. Implications for breeding are discussed.

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Tore Skrøppa

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Tore Skrøppa Halvor Solheim Arne Steffenrem

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Tore Skrøppa

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Tore Skrøppa Arne Steffenrem

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Apulia Project Biodiversity of legume Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Igor A. Yakovlev Harald Kvaalen Arne Steffenrem

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Tore Skrøppa Igor A. Yakovlev Harald Kvaalen Arne Steffenrem

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Tore Skrøppa Igor A. Yakovlev Harald Kvaalen Arne Steffenrem

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Tore Skrøppa Igor A. Yakovlev Harald Kvaalen Arne Steffenrem

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Tore Skrøppa Igor A. Yakovlev Harald Kvaalen Arne Steffenrem

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Tore Skrøppa Jørn Henrik Sønstebø Arne Steffenrem

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Tore Skrøppa Jørn Henrik Sønstebø Arne Steffenrem

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Igor A. Yakovlev YeonKyeong Lee Björn Rotter Jorunn Elisabeth Olsen Tore Skrøppa Øystein Johnsen Carl Gunnar Fossdal

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Embryogenesis is the initial stage of plant life, when the basics of body plan and the post-embryonic development are laid down. Epigenetic memory formed in the Norway spruce embryos permanently affect the timing of bud burst and bud set in progenies, vitally important adaptive traits in this long-lived forest species. The epigenetic memory marks are established in response to the temperature conditions prevailing during zygotic and somatic embryogenesis; the epitype is fixed by the time the embryo is fully developed and is mitotically propagated throughout the tree’s life span. Somatic embryogenesis closely mimics the natural zygotic embryo formation and results in epigenetically different plants in a predictable temperature-dependent manner with respect to altered phenology. Using Illumina-based Massive Analysis of cDNA Ends, the transcriptome changes were monitored in somatic embryos during morphogenesis stage under two different temperatures (18 vs. 30 °C). We found distinct differences in transcriptomes between the genetically identical embryogenic tissues grown under the two epitype-inducing temperatures suggesting temperature-dependent canalizing of gene expression during embryo formation, putatively based on chromatin modifications. From 448 transcripts of genes coding for proteins involved in epigenetic machinery, we found 35 of these to be differentially expressed at high level under the epitype-inducing conditions. Therefore, temperature conditions during embryogenesis significantly alter transcriptional profiles including numerous orthologs of transcriptional regulators, epigenetic-related genes, and large sets of unknown and uncharacterized transcripts.

Authors

Mari Mette Tollefsrud Yoshiaki Tsuda Jørn Henrik Sønstebø Małgorzata Latałowa Laura Parducci Thomas Källman Jun Chen Vladimir Semerikov Tore Skrøppa Giovanni Guiseppe Vendramin Christoph Sperisen Martin Lascoux

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During the Last Glacial Maximum, the boreal vegetation was greatly restricted. Climatic variation between regions had different impact on the glacial and postglacial history of tree species, resulting in contrasting distribution of genetic diversity. Norway spruce (Picea abies) and Siberian spruce (P. obovata) are two closely related species which parapatric ranges cover almost the entire boreal region of Eurasia; a vast region that experienced contrasting glacial histories. In the present study we combined extensive paleobotanical and genetic data to reconstruct the joint histories of the two species and to evaluate how their glacial and postglacial histories have affected their genetic structure. Today, Norway spruce and Siberian spruce are clearly genetically differentiated in mitochondrial (mt) and nuclear SSR markers, suggesting that the two species had largely independent glacial histories. Nuclear SSR markers indicate the presence of hybrid individuals on both sides of the Urals and east-west longitudinal genetic structures indicate a wide zone of hybridization. The border for mtDNA is situated along the Ob River in Siberia. Along this river and eastwards, latitudinal genetic structures were weak. In Norway spruce, rather complex population genetic structures are revealed as a result of multiple refugia and contrasting recolonization patterns. The current distribution of Norway spruce is divided into a southern and a northern domain. Coherent with the paleodata, both mtDNA and SSR loci suggest a long lasting separation between these two domains, which however, did not preclude secondary contacts. Within the southern domain, mtDNA and paleodata suggest the presence of several refugia, a pattern that nuclear SSR loci fail to reveal probably reflecting pollen mediated gene flow. In the northern domain, the same data support the recolonization of Scandinavia during the mid Holocene from a large and scattered refugium located on the East European Plain. Recolonization took place along different migration routes, and diversity evolved differentially along these routes. The complex genetic structure at nuclear SSRs in the northern Norway spruce domain may be due to gene flow from the southern domain, gene flow from the hybrid zone along the Ural Mountains and expansion from a separate refugium along the Atlantic coast. The latter is suggested by ancient DNA, the presence of a Scandinavia endemic mitochondrial haplotype and possibly, the current structure at SSR loci, where the origin of a distinct genetic cluster in Central Scandinavia remains to be elucidated. The implications of these findings for the response of the boreal forest to climate, forest management and breeding will be discussed.

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Authors

René I. Alfaro Bruno Fady Giovanni Giuseppe Vendramin Ian K. Dawson Richard A. Fleming Cuauhtémoc Sáenz-Romero Roberto A. Lindig-Cisneros Trevor Murdock Barbara Vinceti Carlos Manuel Navarro Tore Skrøppa Giulia Baldinelli Yousry A. El-Kassaby Judy Loo

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The current distribution of forest genetic resources on Earth is the result of a combination of natural processes and human actions. Over time, tree populations have become adapted to their habitats including the local ecological disturbances they face. As the planet enters a phase of human-induced climate change of unprecedented speed and magnitude, however, previously locally-adapted populations are rendered less suitable for new conditions, and ‘natural’ biotic and abiotic disturbances are taken outside their historic distribution, frequency and intensity ranges. Tree populations rely on phenotypic plasticity to survive in extant locations, on genetic adaptation to modify their local phenotypic optimum or on migration to new suitable environmental conditions. The rate of required change, however, may outpace the ability to respond, and tree species and populations may become locally extinct after specific, but as yet unknown and unquantified, tipping points are reached. Here, we review the importance of forest genetic resources as a source of evolutionary potential for adaptation to changes in climate and other ecological factors. We particularly consider climate-related responses in the context of linkages to disturbances such as pests, diseases and fire, and associated feedback loops. The importance of management strategies to conserve evolutionary potential is emphasised and recommendations for policy-makers are provided.

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Tore Skrøppa Halvor Solheim Ari Hietala

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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CGRFA FAO Tore Skrøppa

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Tore Skrøppa

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Gunnar Jansson Darius Danusevičius Helmut Grotehusman Jan Kowalczyk Diana Krajmerova Tore Skrøppa Heino Wolf

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Norway spruce (Picea abies (L.) Karst.) is one of the most important coniferous species in Europe both from an economic and ecological point of view. Solid wood products and pulp and paper products have the largest economic value. The patterns of variation observed in Norway spruce provenance trials show geographic variability on a large scale. Genetic variation is also present among offspring from natural populations within the same provenance region and among progenies from trees in the same population. This variation can often be larger than the variability among provenances. Tree improvement of Norway spruce started in Europe in the late 1940s. Breeding programmes were initiated in nearly all European countries but with different intensities. A common objective has been to create base material for seed procurement. Breeding objectives differ between countries, but most of them include adaptation and health, volume production and wood quality in some way. Genetic gains in volume per area unit from first round of seed orchards is around 10 % and from new seed orchards established with tested material expected to be between 20 and 25 %.

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Tore Skrøppa

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Tor Myking Morten Walløe Tvedt Øyvind Meland Edvardsen Henrik Hallingbäck Ditte Christina Olrik Gunnar Friis Proschowsky Mari Rusanen Sanna Black-Samuelsson Tore Skrøppa

Abstract

Continued flexible exchange of forest genetic resources (FGR) in the Nordic region is important for sustainable forest management and for climate change adaptation and mitigation. For this reason, a high level political initiative identified a need to clarify the legal status of FGR in the Nordic region. The overall aim of this study was to assess whether it is necessary and possible to take legal steps to ensure that FGR remain available for conservation and sustainable use in and between the Nordic countries. A survey of the present situation revealed that although the Nordic countries have different domestic legislation on access to FGR, it has not caused any hinders for exchange. Thus, in effect the situation is quite similar in the Nordic countries. As for the future, it is unlikely that application of patent law and plant variety protection (UPOV) will restrict exchange of FGR, mainly due to the short protection periods of these regulations relative to the long generation time of main forestry tree species. For short rotation tree species, intellectual property rights (IPR) might prove to be more applicable. Concerning international agreements, it is premature to evaluate the effect of the Nagoya Protocol (2010) on access and benefit sharing for FGR, as well as recent FAO initiatives. Based on the current study, no legal steps or action seem necessary. To promote continuing simple exchange of FGR the Nordic countries are recommended to stay involved in those processes where relevant international agreements are debated and developed, facilitate simple procedures for exchange and establish a mechanism for surveillance of biotechnological methods that might increase the use of private property rights on FGR.

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Authors

Igor A. Yakovlev Carl Gunnar Fossdal Tore Skrøppa Jorunn Elisabeth Olsen Anne Hopen Jahren Øystein Johnsen

Abstract

Conifers are evolutionarily more ancient than their angiosperm counterparts, and thus some adaptive mechanisms and features influenced by epigenetic mechanisms appear more highly displayed in these woody gymnosperms. Conifers such as Norway spruce have very long generation times and long life spans, as well as large genome sizes. This seemingly excessive amount of genomic DNA without apparent duplications could be a rich source of sites for epigenetic regulation and modifications. In Norway spruce, an important adaptive mechanism has been identified, called epigenetic memory. This affects the growth cycle of these trees living in environments with mild summers and cold winters, allowing them to adapt rapidly to new and/or changing environments. The temperature during post-meiotic megagametogenesis and seed maturation epigenetically shifts the growth cycle programme of the embryos. This results in significant and long-lasting phenotypic change in the progeny, such as advance or delay of vital phenological processes of high adaptive value, like bud break and bud set. This phenomenon is not only of important evolutionary significance but has clear practical implications for forest seed production and conservation of forest genetic resources. The underlying molecular mechanism that causes the ‘memory’ in long-lived woody species is currently under investigation. Here we summarize the information related to epigenetic memory regulation in gymnosperms, with special emphasis on conifers. The molecular mechanism behind this is still unknown but transcriptional changes are clearly involved. Epigenetic regulation may be realized through several mechanisms, including DNA methylation, histone modification, chromatin remodelling, small non-coding RNAs and transposable element regulation, of which non-coding RNAs might be one of the most important determinants.

Authors

Tore Skrøppa

Abstract

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Authors

Igor A. Yakovlev YeonKyeong Lee Bjørn Rotter Tore Skrøppa Øystein Johnsen Jorunn Elisabeth Olsen Carl Gunnar Fossdal

Abstract

Epigenetic memory marks establishment in Norway spruce occur exclusively during embryogenesis in response to environmental impact, and the epitype is fixated by the time the embryo is fully developed without a change in the DNA sequence. We started large scale studies aimed on identifying and characterizing of genes and regulatory elements involved in the initiation, maintenance, and heritability of epigenetic memory using candidate genes and next generation sequencing approaches. Molecular mechanisms of formation of epigenetic memory were studied on the same full-sibs family zygotic embryo in vitro cultures developed in cold (18°C) and warm (30°C) environmental conditions from proliferation till mature embryo stages. Initially we had found large set (64) of Arabidopsis epigenetic regulator gene homologs in spruce. In general, known epigenetic related genes are very well represented among spruce ESTs. Analysis of the transcription patterns of these genes using RT-PCR in epigenetically different embryogenic samples reveal specific transcription patterns on different stages of embryogenic development dependent on epitype. We are expecting to determine certain stages during embryogenesis when epigenetic memory marks are forming. At the same time, nearly no differences in transcription levels of studied genes had been found in seedlings (4 month old), originated from full-sib families clearly differed in epigenetic response. Using MACE (massive cDNA 3-end sequencing) deep mRNA sequencing on the Illumina GSII platform, we analyzed P. abies transcriptomes by comparison warm and cold originated “embryonic epitypes” developed in cold and warm environmental conditions. Significant differences in transcriptomes between epitypes revealed by high-throughput sequencing will be discussed.

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Authors

Paal Krokene E. Lahr Lars Sandved Dalen Tore Skrøppa Halvor Solheim

Abstract

Ceratocystis polonica and Heterobasidion parviporum are important fungal pathogens in Norway spruce (Picea abies). Tree susceptibility to these pathogens with respect to phenology was studied using artificial fungal inoculations at six stages of bud development, and assessed by measuring phloem necroses in the stems of 2- and 8-year-old trees. Tree capacity for resistance was assessed by measuring phloem nonstructural carbohydrates at each stage. Phloem necroses were significantly larger in trees with fungal versus control inoculations and increased significantly over time. Changes in nonstructural carbohydrates occurred in the trees; a significant decline in starch and a slight but significant increase in total sugars occurred over time. These results suggest that susceptibility to fungal pathogens and carbohydrate levels in the stems of the trees were related to fine-scale changes in bud development. A trade-off may occur between allocation of starch (the major fraction of the stem carbohydrate pool) to bud development/shoot growth versus defence of the stem. Previous tests of plant defence hypotheses have focused on herbivory on plants growing under different environmental conditions, but the role of phenology and the effect of pathogens are also important to consider in understanding plant resource allocation patterns.

Authors

Harald Kvaalen Arne Steffenrem Tore Skrøppa

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Authors

Tore Skrøppa

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Authors

Tore Skrøppa

Abstract

Forests and wooded land cover 39 % of the land area of Norway and productive forest amounts to 8.3 million hectares. Two conifer species, Picea abies and Pinus sylvestris, dominate the forest area; they cover 71 % of the forest area and 84 % of total volume. The annual harvest is at present less than 50 % of the annual increment. Forestry and the wood industry have great financial importance in Norway, and timber and wood products have a gross value of 5 % of the total gross domestic product. Forestry is characterized by small-scale properties which to a large extent are privately owned. The main objective of the forest policy is to promote sustainable forest management with a view to promote active, local and economic development, and to secure biological diversity, considerations for the landscape, outdoor recreation and the cultural values associated with the forest. Forest management plans are important instruments to obtain these goals. Three targeted programmes have high priority in the present forest policy: forests and climate, increased use of wood and bioenergy. Active use of the forest genetic resources may contribute to the success of these programmes. Species composition and distribution of forest trees in Norway is largely determined by the following factors: the invasion of tree species after the Ice Age, subsequent climatic changes and human activities ....

Authors

Tore Skrøppa

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Authors

Igor A. Yakovlev Carl Gunnar Fossdal Tore Skrøppa Harald Kvaalen Jorunn Elisabeth Olsen Øystein Johnsen

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Authors

Tim J. Mullin Bengt Andersson Jean-Charles Bastien Jean Beaulieu Rowland D. Burdon W.S. Dvorak John N. King T. Kondo Jodie Krakowski Steve J. Lee Steve E. McKeand Luc Pâques Annie Raffin John H. Russel Tore Skrøppa Michael Stoehr Alvin Yanchuk

Abstract

This chapter reviews the historical context, economic importance, objectives and achievements to-date for many of the more important conifers undergoing domestication through genetic improvement programmes around the world. These provide examples of the context in which genomic technologies will have an impact in forestry. Unlike many other crop plants and livestock animals, forest trees have only been exposed to a few cycles of breeding and selection, and most retain very large amounts of genetic variation in natural populations. These factors present both opportunities and hurdles in the effective application of genomic technologies to existing operational breeding programmes.

Authors

Tore Skrøppa Igor A. Yakovlev

Abstract

Experimental evidence shows that Norway spruce can adjust adaptive traits by a kind of long-term memory of temperature and day length present at the time of its early seed development. This mechanism is termed epigenetics; changes in gene activity not based on differences in the genetic code and yet transferable from one generation to the next. This is a rapidly growing research field in human, animal and plant genetics.

Authors

Tore Skrøppa

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Tore Skrøppa

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Gunnhild Søgaard Inger Sundheim Fløistad Aksel Granhus Kjersti Holt Hanssen Harald Kvaalen Tore Skrøppa Arne Steffenrem

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No abstract has been registered

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Tore Skrøppa

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Authors

Igor A. Yakovlev YeonKyeong Lee Bjørn Rotter Tore Skrøppa Jorunn Elisabeth Olsen Øystein Johnsen Carl Gunnar Fossdal

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No abstract has been registered

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Igor A. Yakovlev YeonKyeong Lee Bjørn Rotter Tore Skrøppa Øystein Johnsen Jorunn Elisabeth Olsen Carl Gunnar Fossdal

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No abstract has been registered

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Igor A. Yakovlev YeonKyeong Lee Bjørn Rotter Tore Skrøppa Øystein Johnsen Jorunn Elisabeth Olsen Carl Gunnar Fossdal

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No abstract has been registered

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Harald Kvaalen Arne Steffenrem Igor A. Yakovlev Øystein Johnsen

Abstract

We have recently found that Norway spruce (Picea abies (L.) Karst.) can rapidly adjust its adaptive performance, probably through an epigenetic mechanism. This appears to employ a kind of long-term memory of temperature sum and (probably) photoperiod from the time of its embryo development. In our research we made identical controlled crosses and produced seed lots under controlled temperature and day-length conditions and later observed phenology, growth and hardiness traits in the progenies. It was repeatedly found that temperature conditions during seed set, in particular, influence the phenotypes of the offspring; seedlings from seeds produced under warm conditions have later terminal bud set and reduced autumn frost hardiness than those from seed produced under colder conditions, and thus perform like a more southern provenance. When embryonic clones were derived from mature zygotic embryos and were cultured at different temperatures, the plants cultured under warm in vitro temperature were the last to set bud and grew taller than those cultured at lower temperatures. Progenies produced in Norway by Central European mother trees had a bud set curve skewed towards that of the local Norwegian performance. A comparison of the performance of seedlings from seeds collected in the same provenance regions in 1970 and 2006 shows that the more recent seed lots consistently produce taller seedlings with a later bud set, probably due to higher temperatures during seed production in 2006. The effect of reproductive environment has been shown to persist for years. It mimics the variation between provenances from different latitudes and altitudes and may explain much of the observed variability in bud set and early height growth between natural populations of Norway spruce. The observed phenomenon suggests an epigenetic mechanism in the developing embryo, either zygotic or somatic, that senses environmental signals such as temperature and influences adaptive traits. Research is underway to understand the molecular basis of this mechanism. We will discuss the implications of this epigenetic phenomenon for the interpretation of provenance differences, for tree breeding and for its possible role in adaptation to climate change.

Authors

Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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Tore Skrøppa

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Authors

Tore Skrøppa Mari Mette Tollefsrud Christoph Sperisen Øystein Johnsen

Abstract

Seedlings of open pollinated Picea abies families from Norwegian and Central European parent trees standing at three sites in Norway were tested for timing of bud set at the end of the first growth season together with seedlings from control provenances producing seeds at their geographical origin. The parental origins were confirmed with a maternally inherited mitochondrial marker that distinguishes trees of the Northern European range from those of the Central European range. The seedlings from the families of Central European mother trees producing seeds in Norway had on average a bud set more similar to the families of local Norwegian origin producing seeds at the same site than the provenance of the same Central European origin. It is argued that the rapid change in this adaptive trait from one generation to the next can be explained by recent research results demonstrating that day length and temperature conditions during embryo formation and maturation can influence the phenotypic performance of seedlings in Norway spruce. This effect may influence the fitness of naturally regenerated plants produced in plantations of Central European trees in Norway.

Authors

Tore Skrøppa

Abstract

The Svalbard Global Seed Vault provides facilities for the safety deposit of samples of seed of distinct genetic resources of importance to humanity, under black box arrangements and in permafrost conditions supplemented by refrigeration in accordance with internationally agreed standards. The Seed Vault was established by the Norwegian Government in 2008 at 78 degrees North in the Norwegian village of Longyearbyen, on Svalbard, the farthest north you can travel in the world on regularly scheduled commercial jet flight. It is managed in a tripartite arrangement between the Norwegian Ministry of Agriculture and Food, the Global Crop Diversity Trust and the Nordic Genetic Resource Center. The last organisation is responsible for the day to day operation and management and organises deposits in the Seed Vault. The Seed Vault offers the most secure back-up possible for a worldwide network of genebanks that together conserve and make available the biological foundation of agriculture. It contains duplicates of collections of all the world’s major seed crops and a huge range of minor crops. The Seed Vault has a capacity of 4.5 million distinct samples. The seeds are stored in “black-box conditions”, meaning that seed storage boxes remain the property of the institution that sent them, and are not even opened by any party other than the depositor. The storage is provided free of charge. At present, there are more than half a million seed samples in the Vault, origination from 212 countries of the world.

Authors

Tore Skrøppa

Abstract

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Authors

Øystein Johnsen Harald Kvaalen Igor A. Yakovlev O.G. Dæhlen Carl Gunnar Fossdal Tore Skrøppa

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No abstract has been registered

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Mari Mette Tollefsrud Jørn Henrik Sønstebø Christian Brochmann Øistein Johnsen Tore Skrøppa GG Vendramin

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No abstract has been registered

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Tor Myking Pekka Vakkari Tore Skrøppa

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Arne Steffenrem Harald Kvaalen Olav Høibø Øyvind M Edvardsen Tore Skrøppa

Abstract

Genetic parameters were estimated for wood density and spiral grain in two long-term field trials with families of Picea abies (L.) Karst., and for microfibril angle (MfA) and model-predicted wood stiffness (MOEest) at one of the sites. The trials were located at 600-720 m altitude in Norway and the progenies, which were a sample of 13 half-sib families from plus-trees in a breeding population, were 33 years old from seed when measured. Significant genetic variation (p0.05) was found for all wood quality traits. The narrow-sense heritability was estimated to be 0.50 for density (across two sites), 0.38 for MfA, 0.29 for MOEest and 0.37 for spiral grain (across two sites). No significant genotype by environment interactions were found for density or spiral grain (p0.05). Genetic relationships between ring width and wood quality traits were negative for density and MOEest, and positive for MfA. Site index and competition had major effects on wood density and predicted MOEest but not on MfA and spiral grain.

Authors

Tore Skrøppa

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Tore Skrøppa Åsmund Asdal

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Authors

G Besnard V Acherè S Jeandroz Ø. Johnsen G Faivre Rampant Tore Skrøppa JM Favre

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Arne Steffenrem Frode Lindland Tore Skrøppa

Abstract

Progenies from a natural stand of Picea abies planted on a forest site with heterogeneous growth conditions were characterized for genetic and environmental control of internodal and whorl branch formation and lammas growth. The progenies studied were 27 years old from seed and planted in a randomized complete block experiment. Internodes and whorls studied were located in the top section of the trees. Significant genetic variation (p<0.01) was found for a number of internodal and whorl branches. Block means for the length of internodes, a strong indicator for the site index in respective blocks, were correlated strongly with branch dimensions (r >= 0.90), intermediately with the frequency of lammas growth (r = 0.81) and number of branches in whorls (r = 0.68), and only weakly with the number of internodal branches per length unit of internode (r = 0.25). A strong environmental effect on branch dimensions was supported by the relative size of variance components. The results show that the environmental effect expressed by site index dominates the control of branch dimensions, while the number of branches is under stronger genetic control in P. abies.

Authors

Mari Mette Tollefsrud Roy Kissling Felix Gugerli Øystein Johnsen Tore Skrøppa Rachid Cheddadi W.O. van der Knaap Magorzata Lataowa Ruth Terhürne-Berson Thomas Litt Thomas Geburek Christian Brochmann Christoph Sperisen

Abstract

Norway spruce (Picea abies [L.] Karst.) is a broadly distributed European conifer tree whose history has been intensively studied by means of fossil records to infer the location of full-glacial refugia and the main routes of postglacial colonization. Here we use recently compiled fossil pollen data as a template to examine how past demographic events have influenced its modern genetic diversity...

Authors

Tore Skrøppa

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No abstract has been registered

Authors

Tore Skrøppa Ketil Kohmann Øystein Johnsen Arne Steffenrem Øyvind M Edvardsen

Abstract

We present results from early tests and field trials of offspring from two Norway spruce (Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.

Authors

Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tor Myking Tore Skrøppa

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Authors

Arne Steffenrem Pekka Saranpaa PO Lundqvist Tore Skrøppa

Abstract

Genetic- and environmental variation and correlation patterns were characterized for modulus of elasticity (MOE), modulus of rupture (MOR) and related wood traits: latewood proportion, wood density, spiral grain, microfibril angle and lignin content in five full-sib families of Norway spruce.The families were evaluated on the basis of clearwood specimens from the juvenile -mature wood transition zone of 93 sampled trees at age 30 year from seed. Family-means varied significantly (p 0.05) for all wood traits studied except lignin content. MOE varied between 7.9-14.1 GPa among trees and 9.4-11.0 GPa among families. MOR varied between 47-87 MPa among trees and 61-71 MPa among families.Families remained significantly different in an analysis of specific MOE (MOE/density) and MOR (MOR/density). Hence, solely relying on wood density as a wood quality trait in tree breeding would not fully yield the potential genetic gain for MOE and MOR. Correlations between wood structural traits and specific MOE and MOR are presented and discussed.

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Authors

I. A. Yakolev Carl Gunnar Fossdal Øystein Johnsen Olavi Junttila Tore Skrøppa

Abstract

We have made and partially sequenced two subtracted cDNA libraries, one representing genes predominantly expressed in a tree from an early-flushing family of Norway spruce (early-flushing library; EFL) and the second from a late flushing family (late flushing library; LFL), during 4 weeks before bud burst. In the EFL, expressed sequence tags (ESTs) encoding proteins of the photosynthetic apparatus and energy metabolism and proteins related to stress (abiotic and biotic) and senescence were abundant. ESTs encoding metallothionein-like and histone proteins as well as transcription factors were abundant in the LFL. We used quantitative real-time reverse transcription polymerase chain reaction to study the expression patterns of 25 chosen genes and observed that the highest levels of activity for most genes were present when plants were still ecodormant. The results indicate that the late flushing is not a result of a delay in gene activity, but is rather associated with an active transcriptional process. Accordingly, certain metabolic processes may be turned on in order to prevent premature flushing. We discuss the putative role of the studied genes in regulation of bud burst timing. Among the candidate genes found, the most interesting ones were the DNA-binding proteins, water-stress- related genes and metallothioneins. Expression patterns of some genes involved in chemical modification of DNA and histones indicate that epigenetic factors are involved in the timing of bud burst. In the obtained transcriptomes, we could not find genes commonly believed to be involved in dormancy and bud set regulation (PHY, CRY, ABI etc.) in angiosperm plants.

Authors

Tor Myking Tore Skrøppa

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Authors

Øystein Johnsen Carl Gunnar Fossdal Nina Elisabeth Nagy Jørgen A.B. Mølmann OG Dæhlen Tore Skrøppa

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No abstract has been registered

Authors

Øystein Johnsen Ola G Dæhlen Geir Østreng Tore Skrøppa

Abstract

Adaptive traits in Picea abies (Norway spruce) progenies are influenced by the maternal temperatures during seed production. Here, we have extended these studies by testing the effects of maternal photoperiod and temperature on phenology and frost hardiness on progenies. Using eight phytotron rooms, seeds from three unrelated crosses were made in an environmental 2 x 2 factorial combination of long and short days and high and low temperatures. The progenies were then forced to cease growth rapidly at the end of the first growing season. An interactive memory effect was expressed the second growth season. Progenies from high temperature and short days, and from low temperatures and long days, started growth later in spring, ceased shoot growth later in summer, grew taller and were less frost hardy in the autumn than their full siblings from low temperatures and short days, and from high temperatures and long days. Norway spruce has developed a memory mechanism, regulating adaptive plasticity by photoperiod and temperature, which could counteract harmful effects of a rapidly changing climate.

Authors

Tore Skrøppa

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No abstract has been registered

Authors

C Blödner Tore Skrøppa Øystein Johnsen A Polle

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Tor Myking A Herzberg Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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Authors

Elizabeth Silvestrini Marco Michelozzi Tore Skrøppa E Brancaleoni P Ciccioli

Abstract

Head-space sampling (HS) has been combined with enantioselective gas chromatography (GC) for the analysis of chiral and non-chiral monoterpenes present in the cortical tissues of five different Norway spruce clones. (1S)-()--Pinene, (1S,5S)-()sabinene, (1S)-()--pinene, and (4S)-()limonene dominated over (1R)-()--pinene, (1R,5R)-()-sabinene, (1R)-()--pinene, and (4R)-()-limonene.Results showed a large variation in the enantiomeric composition of cortical tissues between different clones. The development of HSGC greatly increased the speed of precise analyses of chiral monoterpenes in small samples and therefore offer excellent opportunities in studies on the ecophysiological and chemotaxomic roles of these chiral components

Authors

Tore Skrøppa Øystein Johnsen Carl Gunnar Fossdal Rudiger Baumann Jørgen A. Mølmann Ola G Dæhlen Nina Elisabeth Nagy G Müller-Starck

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No abstract has been registered

Authors

Tor Myking Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

Authors

Carl Gunnar Fossdal Øystein Johnsen Nina Elisabeth Nagy R Baumann Jørgen A.B. Mølmann Tore Skrøppa

Abstract

Introduction: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research indicates that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We are now looking for molecular mechanisms that can explain this “epigenetic” phenomenon. Material and methods: We have performed identical crosses with the same Norway spruce (Picea abies) parent, as discussed by Skrøppa & Johnsen (1994) and Johnsen et al. (1995), in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis and tested the progenies for bud-set and frost hardiness. We have followed the transcription of the spruce phytochromes PHYO, PHYP and PHYN and the class IV chitinase PaChi4 using Quantitative Multiplex Real-Time PCR. Results and conclusions: The effect of temperature on Adaptive properties is most likely a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (relative to alphaTubulin) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation or other epigenetic effects, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.

Authors

Carl Gunnar Fossdal Øystein Johnsen Rüdiger Baumann Jørgen A. Mølmann Ola Gram Dæhlen Nina Elisabeth Nagy Tore Skrøppa

Abstract

Research indicate that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during seed development. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We have performed identical crosses in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis, tested the progenies for bud-set and frost hardiness, and concluded that the effect of temperature most likely is a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (using RealTime PCR) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.

Authors

Carl Gunnar Fossdal Øystein Johnsen Tore Skrøppa

Abstract

Utvalgt Forelesning/Selected Talk: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research has shown that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We have performed identical crosses in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis, tested the progenies for bud-set and frost hardiness, and concluded that the effect of temperature most likely is a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (using RealTime PCR) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.

Authors

Tobias Zöller Tore Skrøppa Øystein Johnsen Andrea Polle

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No abstract has been registered

Authors

Guillaume Besnard Virginie Acheré Sylvain Jeandroz Øystein Johnsen Tore Skrøppa Patricia Faivre Rampant Jean-Michel Favre

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No abstract has been registered

Authors

Tore Skrøppa

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No abstract has been registered

Authors

Øystein Johnsen Carl Gunnar Fossdal Rüdiger Baumann Jørgen A. Mølmann Ola Gram Dæhlen David Clapham Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tor Myking Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Sándor Bordács Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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Heikki Hänninen Eppo Beuker Ø. Johnsen I Leinonen M Murray L Sheppard Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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J Owens Øystein Johnsen OG Dæhlen Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Ø. Johnsen Tore Skrøppa

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No abstract has been registered

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Tor Myking Tore Skrøppa

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No abstract has been registered

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Tore Skrøppa Øystein Johnsen

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No abstract has been registered

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Tore Skrøppa

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No abstract has been registered

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Øystein Johnsen Tore Skrøppa

Abstract

We have compared bud set and frost hardiness among Norway spruce (Piceas abies (L.) Karst.) provenances and families in two cold-acclimation regimes in a phytotron; low light intensity and high night temperatures (LL-HNT), and high light intensity and low night temperatures (HL-LNT) under shortening day lengths.Nine provenances from 59-66N and altitude 100-700 m within Norway, and nine open-pollinated families from a single stand (61N, 270 m elevation) were used. Both provenances and families started bud set and frost hardening earlier in LL-HNT than in HL-LNT.Correlations between the same trait expressed in two regimes were high for both bud set and hardiness at the provenance level and slightly lower at the family level. The variation among family means in bud set and hardiness was large. The differences found between the family extremes were up to 75% of those found between provenance extremes.The relationship between bud set and frost hardiness was strong among the provenance means within both environments (r = 0.92) but weak for the families (r = 0.22-0.44). Causal factors influencing phenotypic variation within traits and covariation among traits may differ for provenances and families within stands. The strong relationships among traits that are found at the provenance level cannot be generalized to the levels of families or clones.

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Fred Midtgaard Tore Skrøppa Gunnar Ogner Anders Lönneborg

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa Ketil Kohmann

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Tore Skrøppa Øystein Johnsen

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Halvor Solheim Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Halvor Solheim

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Tore Skrøppa Gro Hylen Jon Dierichson

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Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Halvor Solheim Tore Skrøppa

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Halvor Solheim Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa Halvor Solheim

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Ketil Kohmann

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa Olavi Junttila Ola Dæhlen

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BÅ Tømmerås Øystein Johnsen Tore Skrøppa Jarle Inge Holten Ketil Hindar Jarle Tufto

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Ø. Johnsen Jon Dietrichson

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa Gunnar Haug Inger Apeland Geir Østreng

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa T Nikkanen S Routsalainen Øystein Johnsen

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Dag Lindgren

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Øystein Johnsen

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Tore Skrøppa Bengt Persson Anders Persson

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Steen Magnussen

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Jon Dietrichson Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Thorarin Benedikz Tore Skrøppa

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Tore Skrøppa

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Veikko Koski Gösta Eriksson Hans Roulund Adalstein Siggurgeirsson Tore Skrøppa

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Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Finn Roll-Hansen Helga Roll-Hansen Tore Skrøppa

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Øystein Johnsen Tore Skrøppa

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Trygve Berg Åsmund Bjørnstad Cary Fowler Tore Skrøppa

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Hans Roulund Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Torleiv Tho

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James Roberts Gene Namkoong Tore Skrøppa

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Tore Skrøppa

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Håkon Fottland Tore Skrøppa

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Tore Skrøppa

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WM Cheliak Tore Skrøppa J Pitel

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Tore Skrøppa

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Tore Skrøppa RM Rauter Hans Roulund

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Tore Skrøppa

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Tore Skrøppa Jon Dietrichson

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Tore Skrøppa

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Tore Skrøppa Reidar Tutturen

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Jon Dietrichson P. A. Rognerud Oddvar Haveraaen Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa Jon Dietrichson Gisle Skaret

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Tore Skrøppa

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Tore Skrøppa

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Finn H. Brække T. T. Kozlowski Tore Skrøppa

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Tore Skrøppa Jon Dietrichson

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Tore Skrøppa

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Tore Skrøppa

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Tore Skrøppa

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