| 1. |
- Gräns, Daniel, et al.
(författare)
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Genetic variation and relationships to growth traits for microfibril angle, wood density and modulus of elasticity in a Picea abies clonal trial in southern Sweden
- 2009
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 24:6, s. 494-503
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variation in wood density, microfibril angle (MFA), wood stiffness (MOE), height, diameter and volume was investigated in a 26-year-old Norway spruce [(Picea abies (L.) Karst.] clonal trial in southern Sweden. Wood quality measurements were performed on 10 mm increment cores using SilviScan. For MFA, mean values of annual rings showed the highest value (30°) at ring 2 counting from the pith, followed by a steep decrease and a gradual stabilization around ring 12 at approximately 14°. MOE showed a monotonic increase from 5 GPa to 14 GPa when moving from pith to bark. High broad-sense heritability values were found for wood density (0.48), MFA (0.41) and MOE (0.50). All growth traits displayed heritability values of similar magnitudes as reported in earlier studies. The generally high age-age correlations between different sections of the wood cores suggested that early selection for wood quality traits would be successful. Owing to unfavorable genetic correlations between volume and MOE, the correlated response indicated that selection for volume only at age 10 would result in a 0.27% decrease in weighted MOE at age 26 for every 1% increase in volume.
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| 2. |
- Gräns, Daniel
(författare)
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Genetic Variation and the Effect of Herbicide and Fertilization Treatments on Wood Quality Traits in Loblolly Pine
- 2021
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Ingår i: Forest Science. - : Oxford University Press (OUP). - 0015-749X .- 1938-3738. ; 67, s. 564-573
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Tidskriftsartikel (refereegranskat)abstract
- The effect of silvicultural treatments (herbicide, fertilization, herbicide + fertilization) and the interactions with genetic effects were investigated for wood quality traits in a 16-year-old loblolly pine (Pinus taeda L.) genetic test established in southwest Georgia, USA. Fertilizer and herbicide treatment combinations were applied multiple times to main plots containing 25 open-pollinated families as sub plots. Significant differences among treatments were found for all traits. Squared acoustic velocity, used as a surrogate for wood stiffness, was higher in herbicide-only plots compared with other treatments. Wood density was considerably lower in fertilization plots. A large proportion of variance observed for wood quality traits was explained by additive genetic effects, with individual-tree heritabilities ranging from 0.78 (ring 7-16 section wood density) to 0.28 (ring 2-6 section wood density). Corresponding family-mean heritability values were well over 0.86. Genotype-by-treatment interactions were nonsignificant for all traits, indicating no need to match families to silvicultural treatments. Wood quality traits had weak genetic correlations with growth and stem quality traits (stem slenderness, sweep, and branch angle) with a range of -0.33 to 0.43, suggesting that recurrent selection on growth or stem quality traits would not adversely affect wood quality in loblolly pine.Study Implications: Silvicultural treatments of herbicide, fertilization, and their combination had significant effects on wood stiffness and wood density in a 16-year-old loblolly pine genetics-by-silviculture trial. When fertilizer was applied, wood density decreased, but the impact on stiffness was minimal. The herbicide treatment increased wood stiffness. As expected, there were large genetic differences for wood quality traits and growth and stem quality traits. Genetics-by-silvicultural treatment interactions were not significant for wood quality traits; family rankings were quite stable across cultural regimes. Families that performed well under one silvicultural treatment performed well under all treatments.
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| 3. |
- Gräns, Daniel
(författare)
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Genetic Variation in Response to Herbicide and Fertilization Treatments for Growth and Form Traits in Loblolly Pine
- 2016
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Ingår i: Forest Science. - : Oxford University Press (OUP). - 0015-749X. ; 62, s. 633-640
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Tidskriftsartikel (refereegranskat)abstract
- The effects of imposed silvicultural treatments and genetics on growth and form traits were investigated in a 15-year-old loblolly pine (Pinus taeda L.) trial in southwestern Georgia, USA. The trial consisted of four treatment combinations and 25 open-pollinated first- and second-generation families. Average individual-tree stem volume ranged from 185.2 dm(3) in the combined fertilization and herbicide plots to 91.2 dm(3) in the control plots. Variation among treatment combinations was significant for height, volume, sweep, and forking defect but was not significant for branch angle and fusiform rust disease incidence (caused by the fungus Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme). Family effects were significant for all traits across treatments. Individual-tree heritability values ranged from 0.10 (stem sweep) to 0.39 (branch angle). Corresponding family-mean heritability values had a range of 0.60 (stem sweep) to 0.90 (branch angle). Genetic correlations between growth (height and volume) and other traits (rust, branch angle, stem forking, and stem sweep) were low and not significant. The lack of important culture x genetics interactions in the study indicates a low risk of losing value due to suboptimal matching between genetic material and silvicultural prescriptions.
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| 4. |
- Hjelmstedt, P., et al.
(författare)
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Effects of prophylactic antibiotic-treatment on post-surgical recovery following intraperitoneal bio-logger implantation in rainbow trout
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Bio-logging devices can provide unique insights on the life of freely moving animals. However, implanting these devices often requires invasive surgery that causes stress and physiological side-effects. While certain medications in connection to surgeries have therapeutic capacity, others may have aversive effects. Here, we hypothesized that the commonly prescribed prophylactic treatment with enrofloxacin would increase the physiological recovery rate and reduce the presence of systemic inflammation following the intraperitoneal implantation of a heart rate bio-logger in rainbow trout (Oncorhynchus mykiss). To assess post-surgical recovery, heart rate was recorded for 21 days in trout with or without enrofloxacin treatment. Contrary to our hypothesis, treated trout exhibited a prolonged recovery time and elevated resting heart rates during the first week of post-surgical recovery compared to untreated trout. In addition, an upregulated mRNA expression of TNFα in treated trout indicate a possible inflammatory response 21 days post-surgery. Interestingly, the experience level of the surgeon was observed to have a long-lasting impact on heart rate. In conclusion, our study showed no favorable effects of enrofloxacin treatment. Our findings highlight the importance of adequate post-surgical recovery times and surgical training with regards to improving the welfare of experimental animals and reliability of research outcomes. © 2020, The Author(s).
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| 5. |
- Lindström, Anders, et al.
(författare)
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Storability measures of Norway spruce and Scots pine seedlings and assessment of post storage vitality by measuring shoot electrolyte leakage
- 2014
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Ingår i: Scandinavian Journal of Forest Research. - : Taylor & Francis Group. - 0282-7581 .- 1651-1891. ; 29:8, s. 717-724
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Tidskriftsartikel (refereegranskat)abstract
- As indoor frozen storage is increasing in forest tree nurseries it is important to have accurate methods for assessing seedling storability in autumn and methods to determine post-storage vitality. Storability of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) seedlings can be based on determination of dry matter content (DMC) of seedling shoots or by freezing shoots at -25 degrees C and thereafter measure electrolyte leakage (SELdiff-25). To compare these two methods we stored 1-year-old spruce and pine seedlings at different occasions during the autumn. To test if leakage of electrolytes from shoots (SEL) could indicate deteriorated vitality, we measured SEL at the end of storage. After storage seedling viability was determined in a three-week growth test, measuring shoot and root growth capacity (RGC). Determination of freezing tolerance (SELdiff-25) before storage had a better ability to predict the outcome of storage compared to the DMC test. Measuring SEL at the end of the frozen storage period accurately indicated seedling vitality. Seedlings with SEL of 0-5% had a high survival rate whereas SEL over 10% indicated low survival and growth capacity after storage. The SEL method has a potential to become a screening test for identifying batches of seedlings that have been damaged during storage in the nursery.
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| 6. |
- Morgenroth, Daniel, et al.
(författare)
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Continuous gastric saline perfusion elicits cardiovascular responses in freshwater rainbow trout (Oncorhynchus mykiss)
- 2022
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Ingår i: Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology. - : Springer Science and Business Media LLC. - 0174-1578 .- 1432-136X. ; 192, s. 95-106
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Tidskriftsartikel (refereegranskat)abstract
- When in seawater, rainbow trout (Oncorhynchus mykiss) drink to avoid dehydration and display stroke volume (SV) mediated elevations in cardiac output (CO) and an increased proportion of CO is diverted to the gastrointestinal tract as compared to when in freshwater. These cardiovascular alterations are associated with distinct reductions in systemic and gastrointestinal vascular resistance (R-Sys and R-GI, respectively). Although increased gastrointestinal blood flow (GBF) is likely essential for osmoregulation in seawater, the sensory functions and mechanisms driving the vascular resistance changes and other associated cardiovascular changes in euryhaline fishes remain poorly understood. Here, we examined whether internal gastrointestinal mechanisms responsive to osmotic changes mediate the cardiovascular changes typically observed in seawater, by comparing the cardiovascular responses of freshwater-acclimated rainbow trout receiving continuous (for 4 days) gastric perfusion with half-strength seawater (1/2 SW, similar to 17 ppt) to control fish (i.e., no perfusion). We show that perfusion with 1/2 SW causes significantly larger increases in CO, SV and GBF, as well as reductions in R-Sys and R-GI, compared with the control, whilst there were no significant differences in blood composition between treatments. Taken together, our data suggest that increased gastrointestinal luminal osmolality is sensed directly in the gut, and at least partly, mediates cardiovascular responses previously observed in SW acclimated rainbow trout. Even though a potential role of mechano-receptor stimulation from gastrointestinal volume loading in eliciting these cardiovascular responses cannot be excluded, our study indicates the presence of internal gastrointestinal milieu-sensing mechanisms that affect cardiovascular responses when environmental salinity changes.
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| 7. |
- Morgenroth, Daniel, et al.
(författare)
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Coronary blood flow influences tolerance to environmental extremes in fish.
- 2021
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Ingår i: The Journal of experimental biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 224:8
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Tidskriftsartikel (refereegranskat)abstract
- Approximately half of all fishes have, in addition to the luminal venous O2 supply, a coronary circulation supplying the heart with fully oxygenated blood. Yet, it is not fully understood how coronary O2 delivery affects tolerance to environmental extremes such as warming and hypoxia. Hypoxia reduces arterial oxygenation, while warming increases overall tissue O2 demand. Thus, as both stressors are associated with reduced venous O2 supply to the heart, we hypothesised that coronary flow benefits hypoxia and warming tolerance. To test this hypothesis, we blocked coronary blood flow (via surgical coronary ligation) in rainbow trout (Oncorhynchus mykiss), and assessed how in vivo cardiorespiratory performance and whole-animal tolerance to acute hypoxia and warming was affected. While coronary ligation reduced routine stroke volume relative to trout with intact coronaries, cardiac output was maintained by increases in heart rate. However, in hypoxia, coronary ligated trout were unable to increase stroke volume to maintain cardiac output when bradycardia developed, which was associated with a slightly reduced hypoxia tolerance. Moreover, during acute warming coronary ligation caused cardiac function to collapse at lower temperatures, and reduced overall heat tolerance relative to trout with intact coronaries. We also found a positive relationship between individual hypoxia and heat tolerance across treatment groups, and tolerance to both environmental stressors was positively correlated with cardiac performance. Collectively, our findings show that coronary perfusion improves cardiac O2 supply, and therefore, cardiovascular function at environmental extremes, which benefits tolerance to natural and anthropogenically induced environmental perturbations.
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| 8. |
- Morgenroth, Daniel, et al.
(författare)
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Hemodynamic responses to warming in euryhaline rainbow trout: implications of the osmo-respiratory compromise
- 2019
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 222:17
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Tidskriftsartikel (refereegranskat)abstract
- In seawater, rainbow trout (Oncorhynchus mykiss) drink and absorb water through the gastrointestinal tract to compensate for water passively lost to the hyperosmotic environment. Concomitantly, they exhibit elevated cardiac output and a doubling of gastrointestinal blood flow to provide additional O-2 to the gut and increase convective flux of absorbed ions and water. Yet, it is unknown how warming waters, which elevate tissue O-2 demand and the rate of diffusion of ions and water across the gills (i.e. the osmo-respiratory compromise), affects these processes. We measured cardiovascular and blood variables of rainbow trout acclimated to freshwater and seawater during acute warming from 11 to 17 degrees C. Relative to freshwater-acclimated trout, cardiac output was 34% and 55% higher in seawater-acclimated trout at 11 and 17 degrees C, respectively, which allowed them to increase gastrointestinal blood flow significantly more during warming (increases of 75% in seawater vs. 31% in freshwater). These adjustments likely served to mitigate the impact of warming on osmotic balance, as changes in ionic and osmotic blood composition were minor. Furthermore, seawater-acclimated trout seemingly had a lower tissue O-2 extraction, explaining why trout acclimated to freshwater and seawater often exhibit similar metabolic rates, despite a higher cardiac output in seawater. Our results highlight a novel role of gastrointestinal blood perfusion in the osmo-respiratory compromise in fish, and improve our understanding of the physiological changes euryhaline fishes must undergo when faced with interacting environmental challenges such as transient warming events.
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| 9. |
- Morgenroth, Daniel, et al.
(författare)
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Under the sea: How can we use heart rate and accelerometers to remotely assess fish welfare in salmon aquaculture?
- 2024
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Ingår i: Aquaculture. - 0044-8486 .- 1873-5622. ; 579
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in bio-sensing technologies open for new possibilities to monitor and safeguard the welfare of fishes in aquaculture. Yet before taken into practice, the applicability of all novel biosensors must be validated, and the breadth of their potential uses must be investigated. Here, we investigated how ECG and accelerometry-derived parameters measured using bio-loggers, such as heart rate, acceleration and variance of acceleration, relate to O2 consumption rate (MO2) and blood borne indicators of stress and tissue damage to determine how biologgers may be used to estimate stress and welfare. To do this, we instrumented 13 fish with a biologger and an intravascular catheter and subjected them to a swimming protocol followed by a stress protocol throughout which the physiological parameters were measured and analyzed a posteriori. Additionally, based on the empirical data obtained, we calculated the mathematical relationships between the bio-logger data and the other parameters and tested the relationship between the calculated parameters using the linear regression algorithms and the measured parameters. Our results show that acceleration is a good proxy for swimming activity as it is closely related to tail beat frequency. In addition, we show that heart rate, acceleration and variance of acceleration all can be used as predictors for metabolic rate. Accelerometry based data, especially variance of acceleration, significantly explain some of the variation in venous partial pressure of O2, blood lactate and plasma cortisol concentration. Variance of acceleration also significantly explains some of the variation in pH and mean corpuscular hemoglobin concentration. These relationships are explained by variance of acceleration being a good indicator of the onset of burst-swimming activity, which is often followed by acid-base imbalances and release of catecholamines. The results herein indicate that bio-logger data can be used to extrapolate a range of stress-related physiological events when these are accompanied by increases in activity and highlight the great potential of biosensors for monitoring fish welfare.
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| 10. |
- Sundell, Erika, et al.
(författare)
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Energetic savings and cardiovascular dynamics of a marine euryhaline fish (Myoxocephalus scorpius) in reduced salinity
- 2021
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Ingår i: Journal of Comparative Physiology B-Biochemical Systems and Environmental Physiology. - : Springer Science and Business Media LLC. - 0174-1578 .- 1432-136X. ; 191, s. 301-311
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have addressed how reduced water salinity affects cardiovascular and metabolic function in marine euryhaline fishes, despite its relevance for predicting impacts of natural salinity variations and ongoing climate change on marine fish populations. Here, shorthorn sculpin (Myoxocephalus scorpius) were subjected to different durations of reduced water salinity from 33 to 15 ppt. Routine metabolic rate decreased after short-term acclimation (4-9 days) to 15 ppt, which corresponded with similar reductions in cardiac output. Likewise, standard metabolic rate decreased after acute transition (3 h) from 33 to 15 ppt, suggesting a reduced energetic cost of osmoregulation at 15 ppt. Interestingly, gut blood flow remained unchanged across salinities, which contrasts with previous findings in freshwater euryhaline teleosts (e.g., rainbow trout) exposed to different salinities. Although plasma osmolality, [Na+], [Cl-] and [Ca2+] decreased in 15 ppt, there were no signs of cellular osmotic stress as plasma [K+], [hemoglobin] and hematocrit remained unchanged. Taken together, our data suggest that shorthorn sculpin are relatively weak plasma osmoregulators that apply a strategy whereby epithelial ion transport mechanisms are partially maintained across salinities, while plasma composition is allowed to fluctuate within certain ranges. This may have energetic benefits in environments where salinity naturally fluctuates, and could provide shorthorn sculpin with competitive advantages if salinity fluctuations intensify with climate change in the future.
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