Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2023
Forfattere
Kanan K. Saikai Celestine Oduori Evans Situma Simon Njoroge Ruth Murunde John W. Kimenju Douglas W. Miano Solveig Haukeland Danny CoyneSammendrag
Coffee is an important commodity for Kenya, where production is steadily declining, despite a global rise in demand. Of the various constraints affecting production, plant-parasitic nematodes are a significant, but often overlooked, threat. As a perennial crop, treating plantations once infected with nematodes becomes difficult. The current study evaluated the drenching application of two biocontrol agents, Trichoderma asperellum and Purpureocillium lilacinum, for their nematode control efficacy, as well as their impact on the soil nematode community structure on mature, established coffee trees in Kenya. Seven Arabica coffee field trials were conducted over two years on trees of various ages. All the fields were heavily infested with Meloidogyne hapla, the first report of the species on coffee in Kenya. Both fungal biocontrol agents were detected endophytically infecting roots and recovered from soil but not until six months after initial applications. The population densities of M. hapla had significantly declined in roots of treated trees 12 months after the initial application, although soil nematode density data were similar across treatments. Based upon the maturity index and the Shannon index, treatment with T. asperellum led to improved soil health conditions and enrichment of diversity in the microbial community. Application of P. lilacinum, in particular, led to an increased abundance of fungivorous nematodes, especially Aphelenchus spp., for which P. lilacinum would appear to be a preferred food source. The soils in the trials were all stressed and denuded, however, which likely delayed the impact of such treatments or detection of any differences between treatments using indices, such as the functional metabolic footprint, over the period of study. A longer period of study would therefore likely provide a better indication of treatment benefits. The current study positively demonstrates, however, the potential for using biologically based options for the environmentally and climate-smart management of nematode threats in a sustainable manner on established, mature coffee plantations.
Forfattere
Margaret Nyaboke Nyang'au Komivi S. Akutse Khamis Fathiya Miriam Karwitha Charimbu Solveig HaukelandSammendrag
Potato Cyst Nematodes (PCN) (Globodera rostochiensis and G. pallida Woll.) are quarantine pests of potato (Solanum tuberosum L.) worldwide capable of causing significant yield loss and difficult to manage with conventional methods. The study explored the diversity of antagonistic fungi associated with PCN obtained from soil samples collected in Nyandarua and Nakuru Counties in Kenya and their effect on PCN egg viability and hatching was also evaluated. Twelve fungal isolates from five genera were isolated and characterized using morphological and molecular techniques. The twelve isolates were Trichoderma asperellum (4), T. hamatum, T. breve, T. atrobruneum, Amanita basiorubra, Setophoma terrestris (2), Penicillium chrysogenum and Clonostachys rosea. The most abundant isolate was Trichoderma spp. with 58 % occurrence. The effect of seven of the isolates on PCN eggs showed that T. breve and P. chrysogenum reduced egg viability by 41 % and 34 %, respectively while T. asperellum and T. breve reduced their hatching by 50 % on average. Trichoderma atrobrunneum, T. hamatum, and A. basiorubra also reduced the PCN egg viability by 27 % on average. These fungal isolates could provide a potential tool for PCN management in potato production systems for improved yields. However, further studies are warranted to validate these findings under greenhouse and field conditions. A more comprehensive bioprospecting survey for PCN associated antagonistic fungi needs to be extended to other potato growing regions to explore further cyst pathogens.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
James Kisaakye Hendrika Fourie Danny Coyne Laura Cortada Fathiya Mbarak Khamis Sevgan Subramanian Shirlyne Masinde Solveig HaukelandSammendrag
The root-burrowing nematode, Radopholus similis, is reputedly the most damaging nematode pest of banana and responsible for major production losses. In this study, the endophytic potential of 13 fungal isolates was assessed for the management of R. similis in East African Highland bananas (‘Ng’ombe’). All isolates successfully colonised tissue-cultured banana roots, with isolates from Trichoderma, Fusarium and Hypocrea producing the highest (⩾49.1%) and Beauveria isolates the lowest (⩽14.4%) colonisation. The fungal endophytes T. asperellum (ICIPE 700) and H. lixii (ICIPE 697) were the most effective in reducing R. similis densities (>81%) relative to the non-inoculated control. However, the combined inoculation of ICIPE 700 and ICIPE 697 led to greater suppression of R. similis (>21%) relative to individual inoculation. Suppression of R. similis following inoculation of banana roots with ICIPE 700 and/or ICIPE 697 was associated with the significant upregulation of the defence-related gene PR-1, the cell signalling gene calmodulin Ca2+ and the cell-wall-strengthening gene β-1,3-glucan synthase. This study demonstrates the potential for nematode management in bananas with fungal endophytes, especially using the isolates ICIPE 700 and ICIPE 697 when combined.
Forfattere
Natthidech Beesa Buncha Chinnasri Anongnuch Sasnarukkit Tida Dethoup Kansiree Jindapunnapat Agnes W. Kiriga Kanan Saikai Solveig Haukeland Danny CoyneSammendrag
The legume cavalcade, Centrosema pascuorum, is used extensively as a cover crop and as a component of conservation agriculture systems. It is also an attractive rotation or cover crop for the management of root-knot nematodes (RKN; Meloidogyne spp.) as it is a non-host. RKN are persistent pests that are well known to be difficult to control. However, the mechanisms governing the non-host status of cavalcade is unknown. The current study established that cavalcade leaves are toxic to RKN as either aqueous extracts or soil amendments. Bioassays conducted using Meloidogyne javanica showed that a 90% concentration of aqueous extract derived from 1-month-old cavalcade leaves (89 mg crude extract ml−1) suppressed nematode hatch (82.9%) and killed infective second-stage juveniles of M. javanica (85.3%). Soil amendments with 1% (w/w) of 1-month-old cavalcade leaves (0.99 mg crude extract g−1 soil) also provided effective control of M. javanica in the glasshouse on okra. One-month-old leaves appeared more effective than 2- or 3-month-old leaves. The soil amendments had no adverse phytotoxic effect on okra seed germination. Our study demonstrates the potential for using cavalcade leaves or extracts to manage RKN. This may be due to the nematicidal activity of the various compounds in the leaves, such as flavonoids, phenols and terpenoids, which should be further assessed.
Forfattere
Yinyin Luan Ming Li Wei Zhou Yuanyuan Yao Yalin Yang Zhen Zhang Einar Ringø Rolf-Erik Olsen Jihong Liu Clarke Shouqi Xie Kangsen Mai Chao Ran Zhigang ZhouSammendrag
The gut microbiota plays an important role in host health and disease. Our understanding of the fish microbiota lags far behind our knowledge of that of humans and other mammals. Nevertheless, research has highlighted the importance of the microbiota in the health, performance, and various physiological functions of fish. The microbiota has been studied in various fish species, including model animals, economic fish, and wild fish species. The composition of the fish microbiota depends on host selection, diet, and environmental factors. The intestinal microbiota affects the nutritional metabolism, immunity, and disease resistance of the fish host, while the host regulates the intestinal microbiota in a reciprocal way through both immune and non-immune factors. Improved and novel gnotobiotic fish models have been developed, which are important for the mechanistic study of host-microbiota interactions in fish. In this review, we discuss recent progress in fish microbiota research. We describe various aspects of this research, including both studies on fish microbiota variations and fundamental research extending our knowledge of host–microbiota interaction in fish. Perspectives on how fish microbiota research may benefit fish health and industrial sustainability are also discussed.
Forfattere
Simeon Rossmann Erik Lysøe Monica Skogen Håvard Eikemo Marta Janiszewska Mirella Ludwiczewska Sylwester Sobkowiak Jadwiga Śliwka May Bente BrurbergSammendrag
Det er ikke registrert sammendrag
Forfattere
Simeon Rossmann Erik Lysøe Monica Skogen Håvard Eikemo Marta Janiszewska Mirella Ludwiczewska Sylwester Sobkowiak Jadwiga Śliwka May Bente BrurbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
With the impact of the COVID-19 pandemic globally and the energy as well as environmental crises we are facing, achievement of the UN sustainable development goals (SDGs), including SDG2, zero hunger, by 2030, has become very challenging. Sustainable food production and supply is a daunting task requiring the international community to work together to improve agricultural productivity with minimum climate and environmental footprint. Through the support of the Norwegian government’s Ministry of Foreign Affairs to the Sinograin I and Sinograin II projects, Norwegian and Chinese partners have established successful collaboration on food security and sustainable agricultural development. The important results achieved and the experience obtained are shared in this book describing the technologies in-depth and the lessons learnt in detail. Readers are provided with insight into the decade-long fruitful collaboration on agriculture between Norway and China, the similarities and differences in Chinese and Norwegian agriculture, the outcomes of technology implementation in selected regions in China, the benefits of good extension services to farmers in Norway and China, as well as future directions for further collaboration and development of agricultural technologies. This book aims to provide valuable information to all stakeholder groups from policy-makers, to the agro-technology industry, to farmers.
Sammendrag
Overvåkingsprogrammet i 2022 omfattet undersøkelse for tilstedeværelse av furuvednematode (Bursaphelenchus xylophilus) i hogstavfall fra furu og i furubukker av slekten Monochamus. I OK-programmets delaktivitet som omfattet kartlegging av furuvednematode i hogstavfall, ble det tatt 401 flisprøver fra hogstavfall og vindfall av furu (Pinus sylvestris) som hadde tegn på angrep av furubukker i slekten Monochamus. Prøvene ble tatt i Innlandet, Vestfold og Telemark, og Viken. Flisprøvene ble inkubert ved +25°C i to uker før nematoder ble ekstrahert med Baermann-trakt og undersøkt i mikroskop. Furuvednematoden B. xylophilus ble ikke påvist, men den naturlig forekommende arten Bursaphelenchus mucronatus kolymensis ble oppdaget i 16 flisprøver. Siden overvåkingen av furuvednematode startet i 2000, har alle de analyserte flisprøvene, totalt 8924, vært negative for furuvednematode. I OK-programmets delaktivitet som omfattet kartlegging av furuvednematode i furubukker, ble feller med attraktanter for fangst av voksne, flygende furubukker satt opp i Agder, Telemark, Viken (Østfold og Akershus), Hedmark og Trøndelag. Billene ble kuttet i biter og ekstrahert med en modifisert Baermann-trakt. Suspensjonen fra ekstraksjonene ble undersøkt i mikroskop for forekomst av Bursaphelenchus spp. Ingen furuvednematoder ble påvist i de 54 undersøkte billene. Bursaphelenchus mucronatus kolymensis ble ikke heller oppdaget.