| 1. |
- Bergstrand, Karl-Johan, et al.
(författare)
-
Nulägesanalys trädgård
- 2018
-
Rapport (populärvet., debatt m.m.)abstract
- Rapporten Nulägesanalys - trädgård har genomförts inom ramen för projektgruppen Insatsstyrka trädgård. Syftet med inventeringen har varit att ge svar på vem som jobbar med trädgårdsvetenskap, vilka forskargrupper och med vilka forskningsämnen, samt identifiera framtida arbetsfält inom ämnet trädgårdsvetenskap och därmed ge uppslag för framtida utveckling av forskningsfält, utbildning och samverkan. I detta ingår att kartlägga trädgårdsvetenskaplig forskning, utbildning och samverkan vid SLU. Nulägesanalysen förväntas därmed ge en grund för fortsatt strategiskt arbete med att utveckla ämnet trädgårdsvetenskap (Horticultural Science) utifrån inventerade resurser och förutsättningar.
|
|
| 2. |
- Birkhofer, Klaus, et al.
(författare)
-
Methods to identify the prey of invertebrate predators in terrestrial field studies
- 2017
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:6, s. 1942-1953
-
Tidskriftsartikel (refereegranskat)abstract
- Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates. Cage studies are only appropriate for small predator species, but often suffer from a bias via cage effects. The use of prey baits or analyses of prey remains are cheaper than other methods and have the potential to provide per capita predation estimates. These advantages often come at the cost of low taxonomic specificity. Molecular methods provide reliable estimates at a fine level of taxonomic resolution and are free of observer bias for predator species of any size. However, the current PCR-based methods lack the ability to estimate predation rates for individual predators and are more expensive than other methods. Molecular and stable isotope analyses are best suited to address systems that include a range of predator and prey species. Our review of methods strongly suggests that while in many cases individual methods are sufficient to study specific questions, combinations of methods hold a high potential to provide more holistic insights into predation events. This review presents an overview of methods to researchers that are new to the field or to particular aspects of predation ecology and provides recommendations toward the subset of suitable methods to identify the prey of invertebrate predators in terrestrial field research.
|
|
| 3. |
- Egan, Paul A., et al.
(författare)
-
Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- 2021
-
Ingår i: Evolution Letters. - : John Wiley & Sons. - 2056-3744. ; 5:6, s. 636-643
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
|
|
| 4. |
- Hambäck, Peter A, et al.
(författare)
-
Asymmetric indirect interactions mediated by a shared parasitoid: connecting species traits and local distribution patterns for two chrysomelid beetles
- 2006
-
Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 148:3, s. 475-481
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on an asymmetric indirect interaction between two chrysomelid beetles where one species (Galerucella tenella) experiences higher parasitization, and the other species (Galerucella calmariensis) lower parasitization, in mixed compared with monospecific populations. This pattern is likely to be a consequence of differences in life history characteristics, where the inferior species has a smaller body size, a lower fecundity and supports a lower parasitoid density than the superior species. This connection between life history characteristics and interspecific dominance in host–parasitoid systems corresponds to predictions from current community ecology theory, and provides a useful building-block in the development of a predictive theory of parasitoid effects on host coexistence.
|
|
| 5. |
- Hambäck, Peter A., et al.
(författare)
-
Bayesian species delimitation reveals generalist and specialist parasitic wasps on Galerucella beetles (Chrysomelidae) : sorting by herbivore or plant host
- 2013
-
Ingår i: BMC Evolutionary Biology. - : BioMed Central. - 1471-2148. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Background: To understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate indirect interactions such as apparent competition among hosts. Recent studies showed that the parasitoid Asecodes lucens mediate apparent competition between two hosts, Galerucella tenella and G. calmariensis, affecting both interaction strengths and evolutionary feedbacks. The same parasitoid was also recorded from other species in the genus Galerucella, suggesting that similar indirect effects may also occur for other species pairs. Methods: To explore the possibility of such interactions, we sequenced mitochondrial and nuclear genetic markers to resolve the phylogeny of both host and parasitoid and to test the number of parasitoid species involved. We thus collected 139 Galerucella larvae from 8 host plant species and sequenced 31 adult beetle and 108 parasitoid individuals. Results: The analysis of the Galerucella data, that also included sequences from previous studies, verified the five species previously documented as reciprocally monophyletic, but the Bayesian species delimitation for A. lucens suggested 3-4 cryptic taxa with a more specialised host use than previously suggested. The gene data analyzed under the multispecies coalescent model allowed us to reconstruct the species tree phylogeny for both host and parasitoid and we found a fully congruent coevolutionary pattern suggesting that parasitoid speciation followed upon host speciation. Conclusion: Using multilocus sequence data in a Bayesian species delimitation analysis we propose that hymenopteran parasitoids of the genus Asecodes that infest Galerucella larvae constitute at least three species with narrow diet breath. The evolution of parasitoid Asecodes and host Galerucella show a fully congruent coevolutionary pattern. This finding strengthens the hypothesis that the parasitoid in host search uses cues of the host rather than more general cues of both host and plant.
|
|
| 6. |
- Jivegård, Lennart, 1950, et al.
(författare)
-
Effects of three months of low molecular weight heparin (dalteparin) treatment after bypass surgery for lower limb ischemia--a randomised placebo-controlled double blind multicentre trial.
- 2005
-
Ingår i: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1078-5884. ; 29:2, s. 190-8
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To test the hypothesis that long-term postoperative dalteparin (Fragmin), Pharmacia Corp) treatment improves primary patency of peripheral arterial bypass grafts (PABG) in lower limb ischemia patients on acetylsalicylic acid (ASA) treatment. DESIGN: Prospective randomised double blind multicenter study. MATERIALS AND METHODS: Using a computer algorithm 284 patients with lower limb ischemia, most with pre-operative ischemic ulceration or partial gangrene, from 12 hospitals were randomised, after PABG, to 5000 IU dalteparin or placebo injections once daily for 3 months. All patients received 75 mg of ASA daily for 12 months. Graft patency was assessed at 1, 3 and 12 months. RESULTS: At 1 year, 42 patients had died or were lost to follow-up. Compliance with the injection schedule was 80%. Primary patency rate, in the dalteparin versus the control group, respectively, was 83 versus 80% (n.s.) at 3 months and 59% for both groups at 12 months. Major complication rates and cardiovascular morbidity were not different between the two groups. CONCLUSIONS: In patients on ASA treatment, long-term postoperative dalteparin treatment did not improve patency after peripheral artery bypass grafting. Therefore, low molecular weight heparin treatment cannot be recommended for routine use after bypass surgery for critical lower limb ischemia.
|
|
| 7. |
- Krokene, Paal, et al.
(författare)
-
Pest risk categorization – New plant health regulations for Norway : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- 2021
-
Rapport (refereegranskat)abstract
- In an ongoing effort to renew Norwegian regulations related to plants and measures against plant pests, the Norwegian Food Safety Authority asked The Norwegian Scientific Committee for Food and Environment (VKM) which of the currently regulated pests that should still be regulated (either as a quarantine pest (QP) or a regulated non-quarantine pest (RNQP) for Norway), and whether there are any species that should be deregulated. Following such a risk categorization process the Norwegian Food Safety Authority will determine if pest risk assessments (PRA’s) should be performed for quarantine pests. International trade regulations define quarantine pests (QPs) as pests of potential economic importance to an area that are not yet present, or are present but not widely distributed and are subject to official control. A regulated non-quarantine pest (RNQP) is a pest whose presence in plants for planting affects the intended use of those plants with an economically unacceptable impact and which is therefore subject to official control within the territory of the importing contracting party and regulated in international trade. In this report VKM presents an overview of the pest categorisation of some of the pests regulated in the current Norwegian regulation and concludes on whether each pest should be regulated as a potential QP, RNQP or none of these categories for Norway. The pest categorisation process – the process of determining whether a pest has or has not the characteristics of a QP or RNQP – has been done using the FinnPRIO model. The FinnPRIO model is a pest risk ranking tool that uses a hypervolume approach carry out quick, semiquantitative expert assessments and that allows a high number of pest risk categorizations to be done cost-effectively and in a short period of time. In total 33 pests were assessed as per request from the Norwegian Food Safety Authority. Of those 33 pests VKM suggests that the vast majority – 32 pests – are kept as a QPs for Norway. However, one pest, the cherry leafroll nepovirus (EPPO code CLRV00), fulfils the requirements for being a RNQP since it is most likely present in Norway already. Furthermore, one organism, the flatworm Arthurdendyus triangulates (ARDDTR), is suggested to not be regulated as QP or RNQP. This pest does not fulfil the requirements for being a QP since it would probably not cause direct damage to plants if it established in Norway. Also, it does not fulfill the requirements for being a regulated non-quarantine pest(RNQP) since its potential presence in plants for planting does not directly affect the intended use of those plants with an economically unacceptable impact.
|
|
| 8. |
- Muola, Anne, et al.
(författare)
-
Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- 2017
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rugen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
|
|
| 9. |
|
|
| 10. |
- Stenberg, Johan A., et al.
(författare)
-
Herbivore-induced "rent rise" in the host plant may drive a diet breadth enlargement in the tenant
- 2008
-
Ingår i: Ecology. - : Ecological Society of America (ESA). - 0012-9658 .- 1939-9170. ; 89:1, s. 126-133
-
Tidskriftsartikel (refereegranskat)abstract
- Inter- and intraspecies variations in host plant traits are presumably involved in many host shifts by insect herbivores, and elucidating the mechanisms involved in such shifts has been a crucial goal in insect-plant research for several decades. Here we propose that herbivore-induced evolutionary increases in host plant resistance may cause oligophagous insect herbivores to shift to other sympatric plants as currently preferred host plants become increasingly unpalatable. We tested this hypothesis in a system based on the perennial herb Filipendula uhnaria (Rosaceae), whose herbivory defense has become gradually stronger due to prolonged selection by Galerucella tenella (Coleoptera: Chrysomelidae) herbivory in a boreal archipelago. We. show that Galerucella gradually increases its use of the alternative host plant Rubus arcticus (Rosaceae) in parallel to gradually increased resistance in Filipendula. Our results imply that, by driving the evolutionary increase in Filipendula resistance, Galerucella is also gradually making the original host species more unpalatable and thereby driving its own host-breadth enlargement. We argue that such self-inflicted "rent rises" may be an important mechanism behind host plant shifts, which in turn are believed to have preceded the speciation of many phytophagous insects.
|
|
| 11. |
- Stenberg, Johan A, et al.
(författare)
-
Host species critical for offspring fitness and sex ratio for an oligophagous parasitoid : implications for host coexistence
- 2010
-
Ingår i: Bulletin of entomological research. - 0007-4853 .- 1475-2670. ; 100:6, s. 735-740
-
Tidskriftsartikel (refereegranskat)abstract
- In theory, inferior apparent competitors sharing a natural enemy with superior apparent competitors should be excluded in the absence of stabilising factors. Nevertheless, plentiful examples of coexisting apparent competitors exist. In this paper, we show that parasitoid resource competition within hosts affects both parasitoid sex ratio and female body size, with implication for population growth and apparent competition between the two closely related hosts experiencing a strong asymmetry in their interaction. While the superior competitor delivers parasitoids with higher fitness to the shared parasitoid pool, the inferior competitor delivers a higher proportion of female parasitoids. Hence, the inferior host experience an inflow of fit parasitoids from the superior competitor, which should increase the risk of exclusion, but also an outflow of parasitoid females, which should reduce the risk of exclusion and increase stability. We conclude that differential outcomes of parasitoid resource competition in different host species may have profound effects on shared parasitoid populations and should be included in future studies of apparent competition between hosts.
|
|
| 12. |
- Stenberg, Johan A., et al.
(författare)
-
Pest risk assessment of selected Epitrix species : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Epitrix is a taxonomically complex genus, with 162 described species all over the world, and most likely many more undescribed species. Due to taxonomic difficulties identifying the species, there is considerable uncertainty regarding which species that feed on cultivated crops. At least 13 Epitrix species are known to damage the tubers of potato, which is the crop of concern in northern Europe. At least five of those Epitrix species (E. hirtipennis, E. fasciata, E.cucumeris, E. papa and E. pubescens) have established themselves outside their native range, spurring concerns that they may spread further and potentially cause damage in new areas where potato is cultivated. It is unknown how most of these species have moved from country to country, but there have been several interceptions of unknown Epitrix species in shipments of ware potatoes.
|
|
| 13. |
|
|
| 14. |
- Stenberg, Johan A., et al.
(författare)
-
Risk assessment of the biological control product Atheta-System with the organism Atheta coriaria Kraatz : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Atheta-System with the rove beetle Atheta coriaria (Kraatz 1856) as the active organism is sought to be used as a biocontrol agent for augmentation biological control in Norway. Atheta-System is intended for use against soil dwelling stages of fungus gnats (e.g. Bradysiapaupera), shore flies (Scatella stagnalis), and thrips (e.g. Frankliniella occidentallis) in greenhouses, plastic tunnels, and other closed or controlled climate cultivations of horticultural crops, incl. soft-fruit crops, vegetables, ornamentals, and kitchen herbs.
|
|
| 15. |
- Thomsen, Iben M., et al.
(författare)
-
Risk assessment of six commercial mycorrhizal products : Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Mycorrhiza is a beneficial association between plant roots and fungi. This mutualistic symbiosis is essential for plant growth in most natural terrestrial ecosystems and in agriculture. Commercial mycorrhizal products containing fungi and bacteria may promote plant growth, especially on sites without a natural microbial community. Due to the risk of unintended negative effects, introduction of new species or genetically different isolates of native species should always be considered carefully. This report assesses the risk of establishment and spread of six fungal species and six bacterial species included in different commercial mycorrhizal products, as well as the species’ potential impact on Norwegian biodiversity. Most of the evaluated fungi and bacteria are probably present in Norway, even though presence at present data only exist for two of the six fungal species. Establishment of the assessed fungi on the plants and sites where they are applied is considered moderately likely, with medium uncertainty, while establishment of the bacterial species is considered to range from very unlikely to very likely depending on the bacterial group, with low uncertainty. The probability of spread to the wider environment ranges from unlikely (four fungal species), to moderately likely (two fungal species), to very likely (five of the six bacterial species). However, for all species it is considered unlikely that establishment and spread would have negative effects on other native species, habitats and ecosystems in Norway.
|
|
| 16. |
- Weber, Daniela, et al.
(författare)
-
Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- 2020
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Alsanius, Beatrix, et al.
(författare)
-
Updated pest risk assessment of Phytophthora ramorum in Norway
- 2023
-
Rapport (refereegranskat)abstract
- IntroductionThe Norwegian Food Safety Authority has asked the Norwegian Scientific Committee for Food and Environment for an updated pest risk assessment of Phytophthora ramorum in Norway. The previous risk assessment of P. ramorum for Norway is from 2009. Since then, the pathogen has been detected repeatedly in Norway, primarily in parks, garden centres, and nurseries in southwestern Norway. The knowledge base concerning P. ramorum has changed since the last pest risk assessment, with increased genetic knowledge about different populations, lineages, and mating types. The risks associated with P. ramorum have also changed, since the disease has become epidemic in new host plants, such as larch trees in England. This updated pest risk assessment will provide important input to the Norwegian Food Safety Authority’s efforts to develop the Norwegian plant health regulation.MethodsVKM established a project group with expertise in plant health, forest pathology, horticultural plant pathology, plant disease modelling, and pest risk assessment. The group conducted systematic literature searches and scrutinized the relevant literature. In the absence of Norwegian studies, VKM relied on literature from other countries. The group did a quantitative risk assessment describing the level of confidence in the conclusions and identifying uncertainties and data gaps. The report underwent pre-submission commenting and external expert reviewing before final approval and publication.Results and conclusionsPhytophthora ramorum is present in the PRA area but has a restricted distribution, mainly being detected in the southern and southwestern parts of Norway.The only P. ramorum lineage considered to be present in Norway is EU1 with mating type A1. The other lineage in Europe, EU2, has so far mainly been documented from the UK. The most widely distributed multilocus genotype of P. ramorum in Norway is EU1MLG1, which became dominant in Europe (including Norway) after 2008. In North America, the NA1, NA2, and EU1 lineages are known from both nurseries and forests. NA1 and NA2 are of the opposite mating type (A2) than European lineages. Recently, various other lineages of P. ramorum have been described from Asia. The main risks for future problems with P. ramorum in Norway are related to entry and establishment of non-European isolates (of all lineages), as well as emergence of new genotypes in European P. ramorum populations.There are several options for diagnosing P. ramorum to species and lineage (mainly EU1, EU2, NA1, and NA2). From a management perspective it is more important to distinguish these entities than mating type and isolate groups (genotypes). The latter are mainly relevant for research purposes or in cases of unexpected disease developments, such as new hosts, increased spread or more severe symptoms on known hosts. However, for more detailed regulation, monitoring, and management of P. ramorum it could also be useful to test for genotypes, i.e. to distinguish EU1MLG1 from other genotypes.Rhododendron remains the most important host plant for P. ramorum in Norway, both in terms of imported plants and detections (mainly in nurseries, garden centres, and public parks). Species in other ornamental plant genera, such as Viburnum, Pieris, and Kalmia, are also listed as major hosts in Europe, and P. ramorum has been detected at least once on species in all these genera in Norway. In the US, Rhododendron, Viburnum, Pieris, Syringa, and Camellia are considered to be the main ornamental hosts. In Norway, there has been one documented detection of P. ramorum on Syringa. Vaccinium and several tree species are potential hosts in the wider environment in Norway, but these hosts are most likely to be infected on sites where rhododendrons are affected by P. ramorum.We consider the probability of entry of P. ramorum to Norway to be very likely, with a low level of uncertainty. Plants for planting, in particular rhododendron and other ornamental hosts, remain the most important entry pathway for P. ramorum. Due to the high import volumes to Norway from Europe, nurseries in the EU are still the main sources of infected plants.If efforts to prevent import of infected plants and to eradicate P. ramorum infestations are discontinued, we consider it very likely that the pathogen will eventually establish in or spread to new areas in Norway. There is a high potential for establishment and spread of P. ramorum along the southwestern and southern coast of Norway, where climatic conditions are favourable for the pathogen and rhododendron and other hosts are common.We consider the overall probability of spread of P. ramorum in Norway after establishment to be moderately likely, with a medium level of uncertainty. Despite repeated detections of the pathogen in some locations, further spread seems to be local and limited. New sites with P. ramorum outbreaks have been rare in Norway in the last decade. Whether this is due to import regulations, eradication efforts (removal of infected plants) or other factors is difficult to determine. Despite the limited spread of P. ramorum in Norway so far, the potential for persisting infections and spread in areas with a conducive climate (high precipitation) cannot be ignored.Phytophthora ramorum still meets the criteria for being regulated as a potential quarantine pest, at least all other lineages than EU1 – thought to be the only lineage present in Norway. For the EU1 lineage, a possible categorization for European isolates is ‘regulated nonquarantine pest’, whereas non-European EU1 isolates fulfil the criteria of being a quarantine pest. Within the EU1 lineage there are different isolate groups, and new genotypes may arise. If the genotype of EU1 isolates detected in imported plant materials differs from isolates that are already present in Norway, European EU1 isolates also fit the category ‘quarantine pest’.The potential effect of introducing new lineages, mating types or isolate groups is considered to be similar for new areas in Norway and areas where P. ramorum is already present. If the pathogen becomes widely spread and/or more genotypically diverse, the potential for damage is considered to be high, due to disease development in infected trees and the possibility of shifts in host plants. In addition to preventing new introductions, it is important to limit domestic spread of the pathogen from known infestations and, if possible, to eradicate P. ramorum from those sites. The longer P. ramorum is present at a site, and the more widespread the pathogen becomes, the higher is the risk that the pathogen will adapt to (new) local hosts and environmental factors.Monitoring host plants for symptoms and testing for the presence of P. ramorum, especially on imported plants, remain the best risk-reducing options. Other effective risk-reducing options are prompt removal and destruction of infected ornamental hosts, in particular rhododendron, and to not replant with susceptible plant species. For infected trees, the best management measures depend on the situation, but infected larch trees should always be removed and destroyed. For non-transmissive tree species, such as beech, the risk of inadvertently spreading the pathogen during felling activities should be weighed against the risk associated with leaving an infected tree on site. Finally, it can be useful to run public awareness campaigns about the importance of cleaning soil from footgear and other items after visiting areas where P. ramorum is present (both in Norway and abroad), as well as other risk-reducing options for private gardens.
|
|
| 21. |
|
|
| 22. |
- Axelsson, Petter, et al.
(författare)
-
Associational resistance mediates interacting effects of herbivores and competitors on fireweed performance
- 2014
-
Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 15, s. 10-17
-
Tidskriftsartikel (refereegranskat)abstract
- Neighboring plants may have dual roles in relation to focal plants, being both competitors, and mediators of associational resistance (AR), or associational susceptibility (AS) to herbivores. Even though these two roles are played out simultaneously in nature, they have traditionally been studied separately. We conducted a two-by-two factorial experiment by manipulating the occurrence of neighbors (meadowsweet, Filipendula ulmaria) and shared mammal herbivores (moose, Alces alces) to investigate how the two simultaneously affect the performance of focal fireweed (Chamerion angustifolium) plants.We found that interactions between mammal herbivory and neighbors had significant effects on fireweed performance. These effects were explained by two counteracting mechanisms. First, when mammal herbivores were present, fireweed experienced AR such that plants growing outside of meadowsweet patches had an almost tripled risk of being browsed compared to plants growing among meadowsweet, resulting in reduced fireweed reproduction and growth. Second, when mammals were excluded, the association with meadowsweet had a direct negative effect on fireweed growth rates - mainly due to competition for light. Additionally, for the first time, we show that association with neighbors affected mammal-induced branching in fireweed.This study demonstrates that AR mediated by mammal herbivores can flip plant-plant interactions from competitive (-) to facilitative (+), and affect plant architecture. As AR and competition are probably simultaneously co-occurring forces, interactions between the two are likely common and thus of fundamental importance for populations and communities.
|
|
| 23. |
|
|
| 24. |
- Björkman, Christer, et al.
(författare)
-
Food Conditioning Affects Expression of Insect Resistance in Diploid Willows (Salix spp.)
- 2013
-
Ingår i: American Journal of Plant Sciences. - : Scientific Research Publishing, Inc.. - 2158-2742 .- 2158-2750. ; 4, s. 48-52
-
Tidskriftsartikel (refereegranskat)abstract
- The high energy quota and versatility of use make willows (Salix spp.) attractive as bioenergy crops. Insect defoliation constitutes a threat to the profitability of willow growers. Hitherto, the breeding for resistance against the main insect pests has been hampered by the fact that all known resistant willow clones are polyploids, and existing molecular breeding tools work most effectively for diploids. Here, we firstly report diploid willows highly resistant to the main insect defoliator, the leaf beetle (Phratora vulgatissima), offering new opportunities for breeding resistance. Leaf bee-tles exposed to three resistant clones (two S. purpurea one S. eriocephala) laid three to 27 times fewer eggs than fe-males on a susceptible S. viminalis clone. Secondly, we show that beetles laid significantly more eggs on resistant clones if they were fed the susceptible clone prior to the oviposition monitoring test compared to when they pre-fed on resistant clones. Nevertheless, the differences observed between resistant and susceptible clones were pronounced in all cases. The food conditioning effect means that small differences in resistance among clones may be undetected.
|
|
| 25. |
|
|
| 26. |
- Brown, Mark A., et al.
(författare)
-
Detection of vitamin K-dependent proteins in venoms with a monoclonal antibody specific for gamma-carboxyglutamic acid.
- 2002
-
Ingår i: Toxicon. - 0041-0101. ; 40:4, s. 447-453
-
Tidskriftsartikel (refereegranskat)abstract
- gamma-Carboxyglutamic acid (Gla) is an unusual amino acid that is synthesized post-translationally from glutamate in a vitamin K-dependent reaction. The dicarboxylic side chain of Gla chelates Ca(2+), a property important for the biological activity of vitamin K-dependent proteins. To date, Gla-containing polypeptides have been identified in venom from two groups of organisms: elapid snakes, and snails of the genus Conus. In certain elapid snakes, a gamma-carboxylated coagulation factor Xa-like protein is a component of the venom whereas cone snails utilize Gla in a range of peptide neurotoxins. Using a monoclonal antibody that specifically recognizes Gla residues, venom samples from various organisms were screened by western blotting and immunofluorescence assays. Amino acid analyses were also performed on most samples. A survey of 21 snake species from 12 genera detected gamma-carboxylated polypeptides only in venom of snakes from the elapid subfamily Acanthophiinae. Gla-containing polypeptides were also observed in cone snail venom but not in venom or toxic salivary secretions from several other organisms. The Gla-specific antibody used here provides a simple immunochemical means to detect gamma-carboxylated polypeptides in venom and may allow new species to be identified that utilize Gla in the biosynthesis of toxic polypeptides.
|
|
| 27. |
- Dalin, Peter, et al.
(författare)
-
Importance of temperature for the performance and biocontrol efficiency of the parasitoid Perilitus brevicollis (Hymenoptera: Braconidae) on Salix
- 2012
-
Ingår i: BioControl. - : Springer Science and Business Media LLC. - 1386-6141 .- 1573-8248. ; 57, s. 611-618
-
Tidskriftsartikel (refereegranskat)abstract
- With the prospect of warmer temperatures as a consequence of ongoing climate change, it is important to investigate how such increases will affect parasitoids and their top-down suppression of herbivory in agroecosystems. Here we studied how the performance and biocontrol efficiency of the willow "bodyguard" Perilitus brevicollis Haliday (Hymenoptera: Braconidae) were affected at different constant temperatures (10, 15, 20, 25A degrees C) when parasitizing a pest insect, the blue willow beetle (Phratora vulgatissima L., Coleoptera: Chrysomelidae). Parasitism did not reduce herbivory at all at 10A degrees C, indicating poor biocontrol efficiency at low temperatures. At higher temperatures, however, parasitism reduced herbivory substantially, implying that biocontrol may be promoted by a warmer climate. Parasitoid performance (survival and development rate) generally increased with increasing temperature up to 20A degrees C. The only exception was body size, which followed the temperature-size rule and decreased with increasing temperature. Our results indicate that a warmer climate may enhance the biocontrol of the blue willow beetle in environments that currently are cooler than the parasitoid's optimal temperature for development.
|
|
| 28. |
- de La Cruz Arguello, Ivan M., et al.
(författare)
-
Evolutionary Ecology of Plant-Arthropod Interactions in Light of the “Omics” Sciences: A Broad Guide
- 2022
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 13
-
Forskningsöversikt (refereegranskat)abstract
- Aboveground plant-arthropod interactions are typically complex, involving herbivores, predators, pollinators, and various other guilds that can strongly affect plant fitness, directly or indirectly, and individually, synergistically, or antagonistically. However, little is known about how ongoing natural selection by these interacting guilds shapes the evolution of plants, i.e., how they affect the differential survival and reproduction of genotypes due to differences in phenotypes in an environment. Recent technological advances, including next-generation sequencing, metabolomics, and gene-editing technologies along with traditional experimental approaches (e.g., quantitative genetics experiments), have enabled far more comprehensive exploration of the genes and traits involved in complex ecological interactions. Connecting different levels of biological organization (genes to communities) will enhance the understanding of evolutionary interactions in complex communities, but this requires a multidisciplinary approach. Here, we review traditional and modern methods and concepts, then highlight future avenues for studying the evolution of plant-arthropod interactions (e.g., plant-herbivore-pollinator interactions). Besides promoting a fundamental understanding of plant-associated arthropod communities’ genetic background and evolution, such knowledge can also help address many current global environmental challenges.
|
|
| 29. |
- Egan, Paul, et al.
(författare)
-
Capturing genetic variation in crop wild relatives: An evolutionary approach
- 2018
-
Ingår i: Evolutionary applications. - : Wiley. - 1752-4571. ; 11, s. 1293-1304
-
Tidskriftsartikel (refereegranskat)abstract
- Crop wild relatives (CWRs) offer novel genetic resources for crop improvement. To assist in the urgent need to collect and conserve CWR germplasm, we advance here the concept of an evolutionary approach. Central to this approach is the predictive use of spatial proxies of evolutionary processes (natural selection, gene flow and genetic drift) to locate and capture genetic variation. As a means to help validate this concept, we screened wild-collected genotypes of woodland strawberry (Fragaria vesca) in a common garden. A quantitative genetic approach was then used to test the ability of two such proxiesmesoclimatic variation (a proxy of natural selection) and landscape isolation and geographic distance between populations (proxies of gene flow potential)to predict spatial genetic variation in three quantitative traits (plant size, early season flower number and flower frost tolerance). Our results indicated a significant but variable effect of mesoclimatic conditions in structuring genetic variation in the wild, in addition to other undetermined regional scale processes. As a proxy of gene flow potential, landscape isolation was also a likely determinant of observed patternsas opposed to, and regardless of, geographic distance between populations. We conclude that harnessing proxies of adaptive and nonadaptive evolutionary processes could provide a robust and valuable means to identify genetic variation in CWRs. We thus advocate wider use and development of this approach amongst researchers, breeders and practitioners, to expedite the capture and in situ conservation of genetic resources provided by crop wild relatives.
|
|
| 30. |
- Egan, Paul, et al.
(författare)
-
Delivering Integrated Pest and Pollinator Management (IPPM)
- 2020
-
Ingår i: Trends in Plant Science. - : Elsevier BV. - 1360-1385 .- 1878-4372. ; 25, s. 577-589
-
Forskningsöversikt (refereegranskat)abstract
- The need to reduce pollinator exposure to harmful pesticides has led to calls to expedite the adoption of integrated pest management (IPM). We make the case that IPM is not explicitly 'pollinator friendly', but rather must be adapted to reduce impacts on pollinators and to facilitate synergies between crop pollination and pest control practices and ecosystem services. To reconcile these diverse needs, we introduce a systematic framework for 'integrated pest and pollinator management' (IPPM). We also highlight novel tools to unify monitoring and economic decision-making processes for IPPM and outline key policy actions and knowledge gaps. We propose that IPPM is needed to promote more coordinated, ecosystem-based strategies for sustainable food production, against the backdrop of increasing pesticide regulation and pollinator dependency in agriculture.
|
|
| 31. |
|
|
| 32. |
- Halitschke, Rayko, et al.
(författare)
-
Shared signals -'alarm calls' from plants increase apparency to herbivores and their enemies in nature.
- 2008
-
Ingår i: Ecology letters. - : Wiley. - 1461-0248 .- 1461-023X. ; 11:1, s. 24-34
-
Tidskriftsartikel (refereegranskat)abstract
- The attraction of natural enemies of herbivores by volatile organic compounds as an induced indirect defence has been studied in several plant systems. The evidence for their defensive function originates mainly from laboratory studies with trained parasitoids and predators; the defensive function of these emissions for plants in natural settings has been rarely demonstrated. In native populations and laboratory Y-tube choice experiments with transgenic Nicotiana attenuata plants unable to release particular volatiles, we demonstrate that predatory bugs use terpenoids and green leaf volatiles (GLVs) to locate their prey on herbivore-attacked plants. By attracting predators with volatile signals, this native plant reduces its herbivore load - demonstrating the defensive function of herbivore-induced volatile emissions. However, plants producing GLVs are also damaged more by flea beetles. The implications of these conflicting ecological effects for the evolution of induced volatile emissions and for the development of sustainable agricultural practices are discussed.
|
|
| 33. |
- Iqbal, Mudassir, et al.
(författare)
-
Bee-Vectored Aureobasidium pullulans for Biological Control of Gray Mold in Strawberry
- 2022
-
Ingår i: Phytopathology. - 0031-949X .- 1943-7684. ; 112, s. 232-237
-
Tidskriftsartikel (refereegranskat)abstract
- Gray mold caused by Botrytis cinerea is a common postharvest disease in strawberries, reducing shelf life considerably. We investigated the potential of the yeast-like biocontrol fungus Aureobasidium pullulans (AP-SLU6) vectored by bumblebees (Bombus terrestris) in the Flying DoctorsVR system to inhibit the pathogen and increase the shelf life of harvested strawberries (cultivar Sonata). Using bumblebees as vectors of various biocontrol agents is becoming increasingly popular, but any potentially negative effects on bee performance have been understudied. Our results show that, over the 4-week period of the trial, the performance and activity of the bees were not negatively affected by A. pullulans. The bees successfully picked up the powder formulation; then, they carried and deposited it on the flowers. The vectoring of the biocontrol agent significantly reduced gray mold development on the harvested fruits by 45% and increased shelf life by 100% in comparison with control treatments. This suggests that the biocontrol fungus applied during flowering successfully reduced Botrytis infection and thus, effectively protected the fruits from gray mold. In addition, the bee-vectored application of the biocontrol agent was found to be significantly more effective than spray application because the latter may temporarily increase humidity around the flower, thereby creating a suitable environment for the pathogen to thrive. In summary, our study demonstrates that A. pullulans vectored by bumblebees can decrease gray mold infection and improve the shelf life of strawberries without adversely affecting the bees, thus providing a basis for the sustainable and efficient control of gray mold on strawberry.
|
|
| 34. |
- Iqbal, Mudassir, et al.
(författare)
-
Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans
- 2021
-
Ingår i: BioControl. - : Springer Science and Business Media LLC. - 1386-6141 .- 1573-8248. ; 66, s. 535-545
-
Tidskriftsartikel (refereegranskat)abstract
- Utilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33-48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.
|
|
| 35. |
- Iqbal, Mudassir, et al.
(författare)
-
Biological control of strawberry diseases by Aureobasidium pullulans and sugar beet extract under field conditions
- 2023
-
Ingår i: Journal of plant pathology. - 1125-4653 .- 2239-7264. ; 105, s. 933-941
-
Tidskriftsartikel (refereegranskat)abstract
- Grey mould (caused by Botrytis cinerea) is the most important pathogen underlying high fungicide dependence in strawberry fields. Reliable biocontrol agents (BCAs) with improved efficiency are needed to replace fungicides. The yeast-like beneficial fungus Aureobasidium pullulans (AP-SLU6) has previously exhibited great potential to combat grey mould in greenhouse environments. Here we report results from a two-year full-factorial field trial in a conventional strawberry field, in which we tested two different concentrations of A. pullulans (10(7) CFU/ml and 10(6) CFU/ml) and sugar beet extract (SBE). The results showed that all the field treatments reduced grey mould severity postharvest and increased shelf life of the harvested fruit in both years. The best effect was achieved using the highest conidial concentration of A. pullulans, which also resulted in 53% higher fruit production compared to the control treatment at the end of the season, indicating a plant-growth promoting effect of the BCA. These results reveal that spray applications of these novel BCAs contribute to reliable biocontrol of grey mould, leading to improvement of the shelf life of strawberry sales boxes. These findings suggest that A. pullulans and SBE can contribute to a shift from chemical fungicides to sustainable methods without compromising cropping security.
|
|
| 36. |
- Johan A., Stenberg
(författare)
-
Miljöövervakning av rikkärr i Skåne 2011–2019
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Analysen av data från inventeringen av rikkärr i Skåne län (2011–2019) visar att abundansen av typiska arter i Skånes rikkärr i genomsnitt är 0,8 arter per provyta, varav mossor står för den ena halvparten och kärlväxter för den andra. Detta är lägre än motsvarande siffror för rikkärr i andra län. Analysen visade även att de typiska arterna är starkt korrelerade till förekomsten av brunmossor, där en hög täckningsgrad har en påtagligt positiv effekt. Däremot påverkas de typiska arterna klart negativt av högväxande vegetation som i sin tur tyder på att hävden inte är optimal i vissa objekt. Föga förvånande är vegetationshöjden klart korrelerad till mängden negativa och högväxande arter.Bottenskiktets mossor domineras av brunmossorna. Trots det är även brunmossornas täckningsgrad i genomsnitt ganska lågt och endast fem kärr har mer än 25 % täckningsgrad av dessa. Täckningsgraderna av vitmossor, spjutmossa och torv är överlag låga och förekomsterna av bleke och skogsarter är nära noll i Skånes rikkärr.Datat från omdreven tyder på att de två rikkärren Bäckhalladalen och Åraslövs mosse har genomgått en negativ förändring under de åtta år som passerat sedan den första inventeringen med en minskning av de typiska arterna. Även vegetationshöjden har ändrats signifikant i de båda kärren och i ett av kärren har brunmossorna minskat kraftigt. Dessa resultat bör dock tolkas med försiktighet och det är inte möjligt att dra några generella slutsatser om utvecklingen av Skånes rikkärr utifrån dessa två objekt.En rarefaction-analys av provytorna indikerar att merparten av alla existerande typiska arter i ett område kan hittas med mindre än 20 provytor. Fler provytor ger bara marginellt bättre fångst. Ett högt antal provytor ger dock andra fördelar. Vi listar flera förbättringsförslag som kan övervägas inför framtida inventeringar.Resultaten tyder på att en optimering av hävden i de missgynnade rikkärren skulle kunna ge en god effekt på deras status. Eftersom områdenas areal och negativa ingrepp inte tycks spela någon avgörande roll för rikkärrens status kan man dra slutsatsen att det är värt att följa upp och vårda även små och negativt påverkade rikkärr.
|
|
| 37. |
- Karlsson Green, Kristina, et al.
(författare)
-
Making sense of Integrated Pest Management (IPM) in the light of evolution
- 2020
-
Ingår i: Evolutionary applications. - : Wiley. - 1752-4571. ; 13, s. 1791-1805
-
Tidskriftsartikel (refereegranskat)abstract
- Integrated Pest Management (IPM) is a holistic approach to combat pests (including herbivores, pathogens, and weeds) using a combination of preventive and curative actions, and only applying synthetic pesticides when there is an urgent need. Just as the recent recognition that an evolutionary perspective is useful in medicine to understand and predict interactions between hosts, diseases, and medical treatments, we argue that it is crucial to integrate an evolutionary framework in IPM to develop efficient and reliable crop protection strategies that do not lead to resistance development in herbivores, pathogens, and weeds. Such a framework would not only delay resistance evolution in pests, but also optimize each element of the management and increase the synergies between them. Here, we outline key areas within IPM that would especially benefit from a thorough evolutionary understanding. In addition, we discuss the difficulties and advantages of enhancing communication among research communities rooted in different biological disciplines and between researchers and society. Furthermore, we present suggestions that could advance implementation of evolutionary principles in IPM and thus contribute to the development of sustainable agriculture that is resilient to current and emerging pests.
|
|
| 38. |
- Koski, Tuuli-Marjaana, et al.
(författare)
-
'Resistance Mixtures' Reduce Insect Herbivory in Strawberry (Fragaria vesca) Plantations
- 2021
-
Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- The transition toward more sustainable plant protection with reduced pesticide use is difficult, because there is no "silver bullet " available among nonchemical tools. Integrating several plant protection approaches may thus be needed for efficient pest management. Recently, increasing the genetic diversity of plantations via cultivar mixing has been proposed as a possible method to reduce pest damage. However, previous studies have not addressed either the relative efficiency of exploiting cultivar mixing and intrinsic plant herbivore resistance or the potential utility of combining these approaches to increase cropping security. Here, using a full factorial experiment with 60 woodland strawberry plots, we tested for the relative and combined effect of cultivar mixing and intrinsic plant resistance on herbivore damage and yield. The experiment comprised two levels of diversity ( "high " with 10 varieties and "low " with two varieties) and three levels of resistance ( "resistant " comprising only varieties intrinsically resistant against strawberry leaf beetle Galerucella tenella; "susceptible " with susceptible varieties only; and "resistance mixtures " with 50:50 mixtures of resistant and susceptible varieties). The experiment was carried out over two growing seasons. Use of resistant varieties either alone or intermixed with susceptible varieties in "resistance mixtures " reduced insect herbivory. Interestingly, resistant varieties not only reduced the mean damage in "resistance mixtures " by themselves being less damaged, but also protected intermixed susceptible varieties via associational resistance. The effect of higher genetic diversity was less evident, reducing herbivory only at the highest level of herbivore damage. In general, herbivory was lowest in plots with high diversity that included at least some resistant varieties and highest in low diversity plots consisting only of susceptible varieties. Despite this, no significant difference in yield (fruit biomass) was found, indicating that strawberry may be relatively tolerant. Our results demonstrate that combined use of high genetic diversity and resistant varieties can help reduce pest damage and provide a useful tool for sustainable food production. "Resistance mixtures " may be particularly useful for sensitive food crops where susceptible varieties are high yielding that could not be completely replaced by resistant ones.
|
|
| 39. |
- Lehrman, Anna, et al.
(författare)
-
Constitutive and herbivore-induced systemic volatiles differentially attract an omnivorous biocontrol agent to contrasting Salix clones
- 2013
-
Ingår i: AoB PLANTS. - : Oxford University Press (OUP). - 2041-2851. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- While carnivores are known to be attracted to herbivore-induced plant volatiles, little is known about how such volatiles may affect the behaviour of omnivorous predators that may use both plants and herbivores as food. Here, we examine how systemically produced plant volatiles, in response to local herbivore damage, differentially attract a key omnivorous predator, Anthocoris nemorum (Heteroptera: Anthocoridae), to single clones of three species of Salix: S. viminalis, S. dasyclados and S. cinerea. The profiles of the plant volatiles produced were found to vary among Salix clones and between herbivore-damaged and intact plants. Anthocoris nemorum was attracted to the volatiles released from undamaged plants of all three species, but most strongly to a native S. cinerea clone. Plants damaged by the herbivorous leaf beetle Phratora vulgatissima (Coleoptera: Chrysomelidae) were generally more attractive than undamaged plants, with A. nemorum responding to systemic changes in the damaged plants where the experimental design specifically excluded volatiles released from the actual site of damage. When comparing damaged plants, the S. dasyclados clone was more attractive to A. nemorum than the S. viminalis clone-a somewhat surprising result since this Salix clone is considered relatively resistant to P. vulgatissima, and hence offers a limited amount of prey. Our experiments highlight that both constitutive and induced plant volatiles play a role in omnivore attraction, and this emphasizes the importance of considering odours of released volatiles when cropping and breeding Salix for increased resistance to herbivores.
|
|
| 40. |
- Lehrman, Anna, et al.
(författare)
-
Estimating direct resistance in willows against a major insect pest, Phratora vulgatissima, by comparing life history traits
- 2012
-
Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703 .- 1570-7458. ; 144, s. 93-100
-
Tidskriftsartikel (refereegranskat)abstract
- Many Salix species (Salicaceae) have a high energy quotum and efficient nitrogen use, resulting in a high and stable biomass production, making these plants suitable as bioenergy crops. However, Salix coppices are sensitive to herbivory by chrysomelid beetles, such as Phratora vulgatissima L. (Coleoptera: Chrysomelidae), and to maintain high biomass yields over several years, durable plant resistance is necessary. We have developed a reliable and efficient bioassay that can be used as a tool for detection of resistance against P. vulgatissima in Salix. Screening of six clones of one susceptible (Salix viminalis L.) and one resistant (Salix dasyclados Wimm.) willow species, by the response of several life history traits of larval and adult P. vulgatissima, identified egg production as the most reliable trait for resistance. We show that a 2-week bioassay of oviposition rate is sufficient for a trustworthy estimation of both total egg production and survival of adult leaf beetles. In addition, to elucidate the variation in resistance among the studied clones, leaf concentrations of various phenolic compounds were compared with the key life history traits of the beetles. Phenolic compounds, especially salicylates, have previously been reported as the main factor controlling Salix resistance against P. vulgatissima. Indeed we found higher levels of salicylates in the resistant clones and larval performance was negatively correlated to the concentration of salicylates in the leaves. In addition, we found indications of negative effects of a luteolin derivative and quercetin-3-glucoside on leaf beetle performance, but further studies are needed to elucidate the specific roles that the different phenolic compounds play in plant resistance.
|
|
| 41. |
- Moritz, Kim, et al.
(författare)
-
Female Salix viminalis are more severely infected by Melampsora spp. but neither sex experiences associational effects
- 2016
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:4, s. 1154-1162
-
Tidskriftsartikel (refereegranskat)abstract
- Associational effects of plant genotype or species on plant biotic interactions are common, not least for disease spread, but associational effects of plant sex on interactions have largely been ignored. Sex in dioecious plants can affect biotic interactions with herbivores and pollinators; however, its effects on plant-pathogen interactions are understudied and associational effects are unknown. In a replicated field experiment, we assessed Melampsora spp. leaf rust infection in monosexual and mixed sex plots of dioecious Salix viminalis L. to determine whether plant sex has either direct or associational effects on infection severity. We found no differences in Melampsora spp. infection severity among sexual monocultures and mixtures in our field experiment. However, female plants were overall more severely infected. In addition, we surveyed previous studies of infection in S.viminalis clones and reevaluated the studies after we assigned sex to the clones. We found that females were generally more severely infected, as in our field study. Similarly, in a survey of studies on sex-biased infection in dioecious plants, we found more female-biased infections in plant-pathogen pairs. We conclude that there was no evidence for associational plant sex effects of neighboring conspecifics for either females or males on infection severity. Instead, plant sex effects on infection act at an individual plant level. Our findings also suggest that female plants may in general be more severely affected by fungal pathogens than males.
|
|
| 42. |
|
|
| 43. |
- Moritz, Kim, et al.
(författare)
-
Plant-sex-biased tritrophic interactions on dioecious willow
- 2014
-
Ingår i: Ecosphere. - 2150-8925. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Plant sex effects on herbivores are well studied, but little is known about these effects on predators and predator-herbivore dynamics. Here we take a holistic approach to study, simultaneously, plant sex effects on herbivore and predator preference and performance, as well as population densities and predation pressure in the field. For dioecious Salix cinerea (grey willow) we found that male plants represented higher host plant quality than females for an omnivorous predator (Anthocoris nemorum, common flower bug), while host plant quality for its herbivorous prey (Phratora vulgatissima, blue willow beetle) was not sex-biased. The herbivore strongly preferred the host plant sex (female) that was suboptimal for the predator, which in turn followed its prey to female plants, leading to plant-sex-biased predation. These results provide new insight into the far-reaching effects of plant sex on insect communities, and open up novel opportunities for improving biocontrol of the herbivore in Salix short rotation coppice.
|
|
| 44. |
- Moritz, Kim, et al.
(författare)
-
Plant sex effects on insect herbivores and biological control in a Short Rotation Coppice willow
- 2017
-
Ingår i: Biological control (Print). - : Elsevier BV. - 1049-9644 .- 1090-2112. ; 115, s. 30-36
-
Tidskriftsartikel (refereegranskat)abstract
- In the wild, plant sex can affect plant-herbivore interactions and higher trophic levels, including natural enemies of the herbivores. However, the possibility of manipulating plant sex to improve biological control and reduce herbivory in domesticated dioecious crops remains unexplored. The dioecious bioenergy crop, Salix viminalis, is often planted in monoclonal, and thus monosexual, fields. We investigated whether using plant clones of either sex, or mixing plants of both sexes, reduced the performance and abundance of the herbivorous pest insect Phratora vulgatissima and its main natural enemy, Anthocoris nemorum, and whether predation was affected. The herbivore laid more eggs, and the predator survived longer, on female plants in the lab. However, these effects did not translate into differences in predation rates in laboratory experiments or differential insect abundances on plants of either sex or plantation sex composition in the field. Plant genotype did have a significant effect on insect abundances, but this was due to plant traits other than sex. The results indicate that manipulating plant sex will not lead to improved biological control or reduced insect herbivory in S. viminalis energy forestry, but suggest that a focus on plant genotypic differences offers promise for improving management practices.
|
|
| 45. |
- Moritz, Kim, et al.
(författare)
-
Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- 2018
-
Ingår i: Environmental and Experimental Botany. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0098-8472 .- 1873-7307. ; 146, s. 62-67
-
Tidskriftsartikel (refereegranskat)abstract
- Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
|
|
| 46. |
- Muola, Anne, et al.
(författare)
-
Folivory has long-term effects on sexual but not on asexual reproduction in woodland strawberry
- 2018
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 8, s. 12250-12259
-
Tidskriftsartikel (refereegranskat)abstract
- Plant fitness is often a result of both sexual and asexual reproductive success and, in perennial plants, over several years. Folivory can affect both modes of reproduction. However, little is known about the effects of folivory on resource allocation to the two modes of reproduction simultaneously and across years. In a 2-year common garden experiment, we examined the effects of different levels of folivory by the strawberry leaf beetle, Galerucella tenella, on current growth, as well as current and future sexual and asexual reproduction (runners) of perennial woodland strawberry, Fragaria vesca. In addition, we measured the chlorophyll content in leaves in the year of experimental damage to determine whether there was increased photosynthetic activity, and, thus, a compensatory response to herbivory. Finally, we tested whether the previous year's folivory, as a result of its effect on plant fitness, affected the level of natural herbivory the plant experienced during the subsequent year. In the year of experimental damage, plants that were exposed to moderate and high levels of folivory (25% and 50% leaf area consumed, respectively) increased their photosynthetic activity compared to control plants. However, only plants exposed to high folivory exhibited negative effects, with a lower probability of flowering compared to control plants, indicating that plants exposed to low or moderate folivory were able to compensate for the damage. Negative effects of folivory were carried over to the subsequent year. Plants that were exposed to moderate folivory (25% leaf area consumed) during first year produced fewer flowers and fruits in the subsequent year. Runner production was consistently unaffected by folivory. The effects of experimental folivory on the level of natural herbivory were mediated via its effects on plant fitness. Our results show that the negative effects of folivory only influence sexual reproduction in woodland strawberry. Furthermore, even though woodland strawberry can tolerate moderate amounts of folivory in the short term, the negative effects on fitness appear later; this highlights the importance of studying the effects of herbivory over consecutive years in perennial plants.
|
|
| 47. |
- Musaqaf, Nimra, et al.
(författare)
-
Effects of strawberry resistance and genotypic diversity on aphids and their natural enemies
- 2022
-
Ingår i: Biological Control. - : Elsevier BV. - 1049-9644 .- 1090-2112. ; 170
-
Tidskriftsartikel (refereegranskat)abstract
- Ecological theory hypothesizes that plant trait diversity may be as important as the presence of specific functional traits (e.g., resistance) for the herbivore and predator communities within a population. We used experimental populations of wild woodland strawberry (Fragaria vesca) to test whether the degree of plant genotypic diversity and/or the existence of specific resistance traits play a role in the host plant’s community structure specifically, the community of generalist and specialist aphids and their natural enemies. In 2019, we studied the aphid abundance and relative predator abundance in an experimental field site in Alnarp, Southern Sweden; the field consisted of plots planted with combinations of 20 different wild strawberry genotypes. These strawberry genotypes were previously identified as either susceptible to or resistant against the herbivorous beetle (Galerucella tenella). Two aphid species, Chaetosiphon fragaefolii (specialist) and the exotic Aphis gossypii (generalist) were found in the plots and of the two species A. gossypii was dominant. The abundance of the specialist aphid (C. fragaefolii) was highest in susceptible plots with high genotypic diversity, while the generalist (A. gossypii) was highest in plots with a mix of resistant and susceptible plants with high genotypic diversity. Anthocorid predators, developed significantly higher population densities in strawberry plots with high genotypic diversity. Overall, predator abundance showed a positive correlation with aphid abundance. These results show that the specific functional trait of resistance as well as plant diversity affected aphids. Knowledge about these effects can be important factors to consider when designing strawberry plantings less susceptible to aphids.
|
|
| 48. |
|
|
| 49. |
- Stenberg, Johan A
(författare)
-
A conceptual framework for integrated pest management
- 2017
-
Ingår i: Trends in Plant Science. - : Elsevier BV. - 1360-1385 .- 1878-4372. ; 22, s. 759-769
-
Tidskriftsartikel (refereegranskat)abstract
- The concept of integrated pest management (IPM) has been accepted and incorporated in public policies and regulations in the European Union and elsewhere, but a holistic science of IPM has not yet been developed. Hence, current IPM programs may often be considerably less efficient than the sum of separately applied individual crop protection actions. Thus, there is a clear need to formulate general principles for synergistically combining traditional and novel IPM actions to improve efforts to optimize plant protection solutions. This paper addresses this need by presenting a conceptual framework for a modern science of IPM. The framework may assist attempts to realize the full potential of IPM and reduce risks of deficiencies in the implementation of new policies and regulations.
|
|
| 50. |
- Stenberg, Johan A
(författare)
-
Aureobasidium spp.: Diversity, Versatility, and Agricultural Utility
- 2023
-
Ingår i: Horticulturae. - : MDPI AG. - 2311-7524. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The black yeast-like fungi Aureobasidium spp. are ubiquitous microorganisms found ina wide variety of extreme and benign environments as saprophytes, endophytes, and pathogens.Since this diverse genus includes species with potential uses in agriculture and the food industry, it isimportant that we explore their evolution and spread in the context of climate change. Aureobasidiumspp. are known to be capable of producing a plethora of various metabolites, many of which findapplications in the field in the control of plant pathogens. The present review aims to explain howthese microorganisms can provide ecological and safe strategies that might be adopted in agriculturalproduction systems and food processing. The versatility and potential of the Aureobasidium genus lieperfectly within the Sustainable Development Goals Agenda 2021–2030 by opening new horizonsthat are respectful to the environment and human health.
|
|
