Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Authors
Nina Elisabeth Nagy Hans Ragnar Norli Monica Fongen Runa Berg Østby Inger Heldal Jahn Davik Ari HietalaAbstract
Tree defense against xylem pathogens involves both constitutive and induced phenylpropanoids and terpenoids. The induced defenses include compartmentalization of compromised wood with a reaction zone (RZ) characterized by polyphenol deposition, whereas the role of terpenoids has remained poorly understood. To further elucidate the tree–pathogen interaction, we profiled spatial patterns in lignan (low-molecular-weight polyphenols) and terpenoid content in Norway spruce (Picea abies) trees showing heartwood colonization by the pathogenic white-rot fungus Heterobasidion parviporum. There was pronounced variation in the amount and composition of lignans between different xylem tissue zones of diseased and healthy trees. Intact RZ at basal stem regions, where colonization is the oldest, showed the highest level and diversity of these compounds. The antioxidant properties of lignans obviously hinder oxidative degradation of wood: RZ with lignans removed by extraction showed significantly higher mass loss than unextracted RZ when subjected to Fenton degradation. The reduced diversity and amount of lignans in pathogen-compromised RZ and decaying heartwood in comparison to intact RZ and healthy heartwood suggest that α-conindendrin isomer is an intermediate metabolite in lignan decomposition by H. parviporum. Diterpenes and diterpene alcohols constituted above 90% of the terpenes detected in sapwood of healthy and diseased trees. A significant finding was that traumatic resin canals, predominated by monoterpenes, were commonly associated with RZ. The findings clarify the roles and fate of lignan during wood decay and raise questions about the potential roles of terpenoids in signal transduction, synthesis, and translocation of defense compounds upon wood compartmentalization against decay fungi.
Authors
Bente Føreid Siv Mari Aurdal Astrid Solvåg Nesse Ingrid Myrstad Trine Hvoslef-Eide Maria DietrichAbstract
No abstract has been registered
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No abstract has been registered
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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.
Abstract
An intensive planting of ‘Celina’ pears on quince ‘Adams’ rootstock was established in May 2015 at NIBIO Ullensvang, western Norway. Five training systems (super spindles, trees with two leaders parallel to the row directions, slender spindles, and V-hedges of trees with 2 or with 4 leaders) were evaluated. Row distance was 3.5 m, and planting distance was 1.0 m except for super spindle trees and V-hedge with two leaders (0.5 m). Cultivars ‘Anna’ and ‘Fritjof’, used as pollinizers, were evenly distributed in the orchard and had good overlapping in flowering time. To get a faster establishment, the trees were headed back in winter 2016 when the formation of the different training systems was started. The first fruits were harvested in 2018. Due to unfavorable pollination conditions, fruit set in 2018 was very low. Average yields varied between 2.7 t ha‑1 for the super spindle trees to 10 t ha‑1 for the spindle trees. As a result of ample flowering and optimum pollination conditions, fruit set in 2019 was excellent, and average yields varied between 17 t ha‑1 for the 2-leader trees planted parallel to the row direction to 47 t ha‑1 for the 2-leader V-hedge trees. Fruit size was inversely related to fruit number per tree. Fruit weight depended on crop load per canopy volume and varied between 130 g for the two smallest trees (super spindles and 2-leader V-hedge system) and 180 g for the 2-leader trees planted parallel to the row direction. Soluble solid contents were high (11% on average), with no differences between training systems. After three cropping years, the spindle trees and V-hedge with 4 leaders per tree were the most productive systems per tree. However, the super spindle and 2-leader V-hedge system with twice the number of trees were the most productive systems per hectare.
Authors
Katherine Ann Gredvig Nielsen Magne Nordang Skårn Gunn Strømeng May Bente Brurberg Arne StensvandAbstract
Control of grey mould, caused by Botrytis spp., is a major challenge in open field strawberry production. Botrytis was isolated from plant parts collected from 19 perennial strawberry fields with suspected fungicide resistance in the Agder region of Norway in 2016. Resistance to boscalid, pyraclostrobin and fenhexamid was high and found in 89.1%, 86.0% and 65.4% of conidia samples, respectively. Multiple fungicide resistance was common; 69.6% of conidia samples exhibited resistance to three or more fungicides. Botrytis group S and B. cinerea sensu stricto isolates were obtained from 19 and 16 fields, respectively. The sdhB, cytb, erg27 and mrr1 genes of a selection of isolates were examined for the presence of mutations known to confer fungicide resistance to boscalid, pyraclostrobin, fenhexamid and pyrimethanil plus fludioxonil, respectively. Allele-specific PCR assays were developed for efficient detection of resistance-conferring mutations in cytb. Among B. cinerea isolates, 84.7%, 86.3% and 61.3% had resistance-conferring mutations in sdhB, cytb and erg27, respectively. A triplet deletion in mrr1, resulting in ΔL497, commonly associated with the multidrug resistance phenotype MDR1h, was detected in 29.2% of Botrytis group S isolates. High frequencies of resistance to several fungicides were also detected in Botrytis from both imported and domestically produced strawberry transplants. Fungicide resistance frequencies were not different among fields grouped by level of grey mould problem assessed by growers, indicating factors other than fungicide resistance contributed to control failure, a fact that has important implications for future management of grey mould.
Abstract
No abstract has been registered
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No abstract has been registered
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Apple cultivars are one of the main factors setting the composition of bioactive compounds in apples and the quality of the fruit. However, research has been providing increasing amounts of data on the influence of rootstocks on the variations in the composition of bioactive compounds in apples. The aim of the study was to determine the influence of rootstocks on the changes in the qualitative and quantitative composition of phenolic compounds and their antioxidant activity in vitro in apple flesh and peel. HPLC analyses of phenolic compounds in apple samples were performed. The rootstock–scion combination had a significant effect on the composition and antioxidant activity of phenolic compounds in apple samples. Depending on the rootstock, the total content of phenolic compounds in apple flesh of the ‘Galaval’ cultivar could vary by 2.9 times, and in the peel by up to 90%. The genotype of the rootstock resulted in the highest variation in total flavan-3-ol content in apple flesh—by as much as 4.3 times—while the total content of flavonols varied by 2.1 times. In apple peel, on the contrary, the greatest variation was recorded for the total flavonol content (by 4.4 times), and the total flavan-3-ol content varied the least (by 1.8 times). A proper match of a cultivar and a rootstock can program a fruit tree to grow larger amounts of higher-quality, antioxidant-rich, and high-nutrition-value fruit.
Authors
Jevgenija Necajeva Aritz Royo-Esnal Donato Loddo Peter Jensen Alireza Taab Agnieszka Synowiec Ahmet Uludag Ilhan Uremis Alistair Murdoch Anna Bochenek Andrea Onofri Kirsten TørresenAbstract
Barnyard grass [Echinochloa crus-galli (L.) Beauv] is a competitive C4 weed species that is widely distributed throughout the world. Although it originated in warm climatic conditions, currently, it is found in Europe as far north as Norway. This study aimed to compare the phenological development of plants from different climatic conditions in varying environmental conditions. To represent the contrasting climatic conditions within Europe, seeds were collected in Norway and Italy, and distributed to the study participants, to be sown at 10 different sites as two common populations. In addition to that, seeds of two to three local populations were collected near each of the sites. The development of the plants was monitored in a pot experiment set up under field conditions. The time to reach heading in the first year of the experiment was 77.6% faster (ranging from 45.9 to 98.3% on average) in the Norwegian than in the Italian population. However, in the leaf development stage, the difference between the common populations was smaller by, 23.5% on average (0–46.7%) and was mostly not significant. Our results indicate that different E. crus-galli ecotypes, characterized by differences in their phenological development, evolved within the distribution area of this species in Europe. However, the early development of the plants progressed with negligible differences between populations. The findings reported here can be used to adapt existing models from one region to regions with different climatic conditions for use in decision support systems and for research into plant population dynamics.