Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2021
Abstract
A new stubby-root nematode belonging to the Trichodorus sparsus complex was found in association with serious damage to Hill’s Yew hedges (Taxus x media ´Hillii´) in Oslo in 2017, characterised by chlorosis, wilting and loss of needles. T. hellalae n. sp. is about 800 μm long with medium-sized onchiostyle (55 μm, average), characterized in male by two ventromedian cervical papillae located beyond the onchiostyle region and with the secretory excretory pore (SE-pore) in between, in most type specimens, three ventromedian precloacal supplements with the posteriormost one opposite the anterior end of spicule manubrium and spicules 40 μm long (average) with widened manubrium, gradually tapered to a narrower blade without ornamentation of striae or bristles, but showing a minor indentation at level of posterior border of capsule of suspensor muscles. Gubernaculum with thickened keel-like posterior end and a thickened refractive anterior border. Females are characterised by a short pear-shaped vagina, less than 1/3rd of corresponding body width and very small rounded triangular vaginal sclerotized pieces in longitudinal optical section and vulva pore-like in ventral view; on each body side one sublateral body pore at about 3.5 body width anterior to vulva and one postadvulvar body pore. According to D2-D3 analyses, the Trichodorus hellalae n. sp. sequences are embedded in a maximally supported clade with several T. variabilis lineages. However, morphological and molecular species delimitation both support Trichodorus hellalae n. sp. as being a new species. Therefore, T. variabilis now appears to in fact consists of several cryptic species.
Authors
Juliet Ochola Danny Coyne Laura Cortada Solveig Haukeland Margaret Ng'ang'a Ahmed Hassanali Charles Opperman Baldwyn TortoAbstract
Bio-communication occurs when living organisms interact with each other, facilitated by the exchange of signals including visual, auditory, tactile and chemical. The most common form of bio-communication between organisms is mediated by chemical signals, commonly referred to as ‘semiochemicals’, and it involves an emitter releasing the chemical signal that is detected by a receiver leading to a phenotypic response in the latter organism. The quality and quantity of the chemical signal released may be influenced by abiotic and biotic factors. Bio-communication has been reported to occur in both above- and below-ground interactions and it can be exploited for the management of pests, such as cyst nematodes, which are pervasive soil-borne pests that cause significant crop production losses worldwide. Cyst nematode hatching and successful infection of hosts are biological processes that are largely influenced by semiochemicals including hatching stimulators, hatching inhibitors, attractants and repellents. These semiochemicals can be used to disrupt interactions between host plants and cyst nematodes. Advances in RNAi techniques such as host-induced gene silencing to interfere with cyst nematode hatching and host location can also be exploited for development of synthetic resistant host cultivars.
Abstract
Plant-parasitic nematodes (PPN) cause significant yield reduction in commercial pineapple (Ananas comosus) worldwide. In Kenya, few nematode studies have been conducted, although the main commercial pineapple producer has sole dispensation to use Telone II (1,3-Dichloropropene) indicating the magnitude of the nematode problem. This study was conducted with the aim to investigate the population densities and diversity of nematodes in two commercial plantations with two contrasting management practices. We additionally assessed the influence of crop age and compared this with nearby smallholder pineapple production systems. Soil and root samples were collected from fields of different ages in each commercial plantation and from 29 smallholder fields. A total of 18 genera were associated with pineapple, with a relatively greater diversity found in smallholder than commercial farms. The most prevalent genus was Meloidogyne spp. (M. javanica) followed by Helicotylenchus spp., Tylenchus spp. and Aphelenchoides spp. PPN densities were higher in relatively older fields of 24 and 36 months than from fallow and 3-month-old fields. Regression analysis additionally demonstrated the rise of PPN densities with age of pineapple fields, especially Meloidogyne spp., while free-living nematode densities declined. This study provides an indication of the high level of PPN infection in pineapple in Kenya, which would constitute an important factor contributing to low yields. The study confirms an obvious need for pineapple producers to control PPN to improve crop yields.
Authors
James Kisaakye Hendrika Fourie Danny Coyne Laura Cortada Shirlyne Masinde Sevgan Subramanian Solveig HaukelandAbstract
The banana weevil (BW), Cosmopolites sordidus, is the main coleopteran pest of banana, causing up to 100% yield loss. In this study, we screened 20 isolates of entomopathogenic fungi (EPF) for the management of BW. In the lab, eight Beauveria bassiana isolates caused >50% mortality of the adult BW, whereas Metarhizium anisopliae and Isaria fumosorosea isolates were less pathogenic. B. bassiana isolates ICIPE 648, ICIPE 660 and ICIPE 273 were the most pathogenic, killing ≥80% of adult BW. B. bassiana isolate ICIPE 622 yielded the highest spores per BW cadaver (1.84 × 108 spores), followed by ICIPE 660, ICIPE 273 and ICIPE 648—1.17 × 108, 3.8 × 107 and 3.6 × 107 spores, respectively. ICIPE 273 had the shortest LT50 (5.3 days) followed by ICIPE 648 (9.8 days) and 660 (11.1 days). Similarly, the LC50 values for the three isolates were 5.18 × 107, 5.49 × 107 and 5.2 × 107 spores mL−1, respectively. In the field, ICIPE 273 and ICIPE 648 had the highest (31.3%) and lowest (20.8%) pathogenicity, respectively. This study indicates that the B. bassiana isolates ICIPE 273, ICIPE 648 and ICIPE 660 are potential candidates for the environmentally sustainable management of BW.
Authors
Annika Pieterse Ben Rowson Louwrens Tiedt Antoinette P. Malan Solveig Haukeland Jenna L. RossAbstract
A new species of Phasmarhabditis was isolated from the slug, Polytoxon robustum, from Nairobi, Kenya. The nematode was identified using morphological, morphometric, molecular and phylogenetic analyses. Phasmarhabditis kenyaensis n. sp. is characterised by an infective juvenile with the longest body length in the genus, measuring 1232 (1107-1336) μm, by the presence of males with a bursa bearing nine bilateral pairs of genital bursal papillae and one pair of papilliform phasmids flanking the tail, cephalate paired spicules, with an arc length of 71 (57-81) μm, as well as by females with a vulva located at the mid-body region and a conoid tail shape, with two phasmids located at ca 40% of the tail length. The molecular phylogeny of the new species, as inferred from its SSU (small subunit) rRNA gene, places P. kenyaensis n. sp. genetically close to undescribed phasmarhabditids from South Africa, suggesting an African grouping, while the D2-D3 (large ribosomal subunit) and ITS region analyses relate P. kenyaensis n. sp. to P. meridionalis, with weak bootstrap support. This is the third new Phasmarhabditis species described from the African continent, the new species bringing the total known complement of the genus to 14 species. A morphometric compendium to all species cultured in vivo is supplied.
Authors
Selamawit Araya Kidane Solveig Haukeland Beira H. Meressa Anne Kathrine Hvoslef-Eide Danny L. CoyneAbstract
Enset (Ensete ventricosum), is a perennial herbaceous plant belonging to the family Musaceae, along with banana and plantain. Despite wild populations occurring in eastern, central and southern Africa, it is only in Ethiopia that the crop has been domesticated, where it is culturally and agriculturally symbolic as a food security crop. Although an under-researched orphan crop, enset serves as a staple food for about 20% of the Ethiopian population, comprising more than 20 million people, demonstrating its value in the country. Similar to banana and plantain, enset is heavily affected by plant-parasitic nematodes, with recent studies indicating record levels of infection by the root lesion nematode Pratylenchus goodeyi. Enset is propagated vegetatively using suckers that are purposely initiated from the mother corm. However, while banana and plantain suckers have proven to be a key source of nematode infection and spread, knowledge on the infection levels and role of enset suckers in nematode dissemination is lacking. Given the high levels of plant-parasitic nematodes reported in previous surveys, it is therefore speculated that planting material may act as a key source of nematode dissemination. To address this lack of information, we assessed enset planting material in four key enset growing zones in Ethiopia. A total of 340 enset sucker samples were collected from farmers and markets and analyzed for the presence of nematodes. Nematodes were extracted using a modified Baermann method over a period of 48 h. The root lesion nematode P. goodeyi was present in 100% of the samples, at various levels of infection. These conclusive results show that planting material is indeed a key source of nematode infection in enset, hence measures taken to ensure clean suckers for planting will certainly mitigate nematode infection and spread. The effect of nematode infection on yield and quality on enset remains to be investigated and would be a way forward to complement the nematode/disease studies conducted so far and add valuable knowledge to the current poorly known impact of pests and diseases.
Abstract
Pratylenchus goodeyi appears to be the most prevalent nematode pest of enset in Ethiopia, where it can occur in extremely high densities. However, the damage to yield or how different enset cultivars react to the nematode has yet to be determined. The current study therefore sought to establish a first assessment of these reactions by enset to P. goodeyi infection. Determining pest resistant cultivars is an important task in developing management strategies. Our study evaluated nine enset cultivars to establish host response and identify potential sources of resistance. In addition, the pathogenicity of P. goodeyi was assessed on three enset cultivars. After 9 months’ growth, significant differences in final population densities (Pf) and reproduction factor (RF) were observed amongst the nine cultivars, with ‘Gefetanuwa’ the most susceptible (Pf = 25 799 and RF = 12.9), and similarly in a repeat experiment for 4.5 months (Pf = 126 534 and RF = 63.3). ‘Maziya’ and ‘Heila’ were the most resistant in the first experiment (Pf < 455 and RF < 0.2) as well as in the repeat, together with ‘Kellisa’ (Pf < 5255 and RF < 2.6). In the pathogenicity experiment four inoculum densities significantly affected the Pf and RF but not among the three cultivars ‘Maziya’, ‘Arkiya’ and ‘Heila’. This is the first known study to assess genotype reaction to P. goodeyi, which shows that there are significant differences in the reactions of different cultivars and that resistance appears to be present in enset.
Abstract
Aquaculture has undergone rapid development in the past decades. It provides a large part of high-quality protein food for humans, and thus, a sustainable aquaculture industry is of great importance for the worldwide food supply and economy. Along with the quick expansion of aquaculture, the high fish densities employed in fish farming increase the risks of outbreaks of a variety of aquatic diseases. Such diseases not only cause huge economic losses, but also lead to ecological hazards in terms of pathogen spread to marine ecosystems causing infection of wild fish and polluting the environment. Thus, fish health is essential for the aquaculture industry to be environmentally sustainable and a prerequisite for intensive aquaculture production globally. The wide use of antibiotics and drug residues has caused intensive pollution along with risks for food safety and increasing antimicrobial resistance. Vaccination is the most effective and environmentally friendly approach to battle infectious diseases in aquaculture with minimal ecological impact and is applicable to most species of farmed fish. However, there are only 34 fish vaccines commercially available globally to date, showing the urgent need for further development of fish vaccines to manage fish health and ensure food safety. Plant genetic engineering has been utilized to produce genetically modified crops with desirable characteristics and has also been used for vaccine production, with several advantages including cost-effectiveness, safety when compared with live virus vaccines, and plants being capable of carrying out posttranslational modifications that are similar to naturally occurring systems. So far, plant-derived vaccines, antibodies, and therapeutic proteins have been produced for human and animal health. However, the development of plant-made vaccines for animals, especially fish, is still lagging behind the development of human vaccines. The present review summarizes the development of fish vaccines currently utilized and the suitability of the plant-production platform for fish vaccine and then addresses considerations regarding fish vaccine production in plants. Developing fish vaccines by way of plant biotechnology are significant for the aquaculture industry, fish health management, food safety, and human health.
Authors
Jens H. Kuhn Scott Adkins Bernard R. Agwanda Rim Al Kubrusli Sergey V. Alkhovsky Gaya K. Amarasinghe Tatjana Avšič-Županc María A. Ayllón Justin Bahl Anne Balkema-Buschmann Matthew J. Ballinger Christopher F. Basler Sina Bavari Martin Beer Nicolas Bejerman Andrew J. Bennett Dennis A. Bente Éric Bergeron Brian H. Bird Carol D. Blair Kim R. Blasdell Dag-Ragnar Blystad Jamie Bojko Wayne B. Borth Steven Bradfute Rachel Breyta Thomas Briese Paul A. Brown Judith K. Brown Ursula J. Buchholz Michael J. Buchmeier Alexander Bukreyev Felicity Burt Carmen Büttner Charles H. Calisher Mengji Cao Inmaculada Casas Kartik Chandran Rémi N. Charrel Qi Cheng Yuya Chiaki Marco Chiapello Il-Ryong Choi Marina Ciuffo J. Christopher S. Clegg Ian Crozier Elena Dal Bó Juan Carlos de la Torre Xavier de Lamballerie Rik L. de Swart Humberto Debat Nolwenn M. Dheilly Emiliano Di Cicco Nicholas Di Paola Francesco Di Serio Ralf G. Dietzgen Michele Digiaro Olga Dolnik Michael A. Drebot J. Felix Drexler William G. Dundon W. paul Duprex Ralf Dürrwald John M. Dye Andrew J. Easton Hideki Ebihara Toufic Elbeaino Koray Ergünay Hugh W. Ferguson Anthony R. Fooks Marco Forgia Pierre B.H. Formenty Jana Fránová Juliana Freitas-Astúa Jingjing Fu Stephanie Fürl Selma Gago-Zachert George Fú Gāo María Laura García Adolfo García-Sastre Aura R. Garrison Thomas Gaskin Jean-Paul J. Gonzalez Anthony Griffiths Tony L. Goldberg Martin H. Groschup Stephan Günther Roy A. Hall John Hammond Tong Han Jussi Hepojoki Roger Hewson Jiang Hong Ni Hong Seiji Hongo Masayuki Horie John S. Hu Tao Hu Holly R. Hughes Florian Hüttner Timothy H. Hyndman M. Ilyas Risto Jalkanen Dàohóng Jiāng Gilda B. Jonson Sandra Junglen Fujio Kadono Karia H. Kaukinen Michael Kawate Boris Klempa Jonas Klingström Gary Kobinger Igor Koloniuk Hideki Kondo Eugene V. Koonin Mart Krupovic Kenji Kubota Gael Kurath Lies Laenen Amy J. Lambert Stanley L. Langevin Benhur Lee Elliot J. Lefkowitz Eric M. Leroy Shaorong Li Longhui Li Jianrong Li Huazhen Liu Igor S. Lukashevich Piet Maes William Marciel de Souza Marco Marklewitz Sergio H. Marshall Shin-Yi L. Marzano Sebastien Massart John W. McCauley Michael Melzer Nicole Mielke-Ehret Kristina M. Miller Tobi J. Ming Ali Mirazimi Gideon J. Mordecai Hans-Peter Mühlbach Elke Mühlberger Rayapati Naidu Tomohide Natsuaki José A. Navarro Sergey V. Netesov Gabriele Neumann Norbert Nowotny Márcio R. T. Nunes Alejandro Olmedo-Velarde Gustavo Palacios Vicente Pallás Bernadett Pályi Anna Papa Sofia Paraskevopoulou Adam C. Park Colin R. Parrish David A. Patterson Alex Pauvolid-Corrêa Janusz T. Pawęska Susan Payne Carlotta Peracchio Daniel R. Pérez Thomas S. Postler Liying Qi Sheli R. Radoshitzky Renato O. Resende Carina A. Reyes Bertus K. Rima Gabriel Robles Luna Víctor Romanowski Paul Rota Dennis Rubbenstroth Luisa Rubino Jonathan Runstadler Sead Sabanadzovic Amadou Alpha Sall Maria S. Salvato Rosemary Sang Takahide Sasaya Angela D. Schulze Martin Schwemmle Mang Shi Xiǎohóng Shí Zhènglì Shí Yoshifumi Shimomoto Yukio Shirako Stuart G. Siddell Peter Simmonds Manuela Sironi Guy Smagghe Sophie J. Smither Jin-Won Song Kirsten Spann Jessica R. Spengler Mark D. Stenglein David M. Stone Jari Sugano Curtis A. Suttle Amy Tabata Ayato Takada Shigeharu Takeuchi David P. Tchouassi Amy Teffer Robert B. Tesh Natalie J. Thornburg Yasuhiro Tomitaka Keizō Tomonaga Noël Tordo Baldwyn Torto Jonathan S. Towner Shinya Tsuda Changchun Tu Massimo Turina Ioannis E. Tzanetakis Janice Uchida Tomio Usugi Anna Maria Vaira Marta Vallino Bernadette van den Hoogen Arvind Varsani Nikos Vasilakis Martin Verbeek Susanne von Bargen Jiro Wada Victoria Wahl Peter J. Walker Lin-Fa Wang Guoping Wang Yanxiang Wang Yaqin Wang Muhammad Waqas Tàiyún Wèi Shaohua Wen Anna E. Whitfield John V. Williams Yuri I. Wolf Jiangxiang Wu Lei Xu Hironobu Yanagisawa Caixia Yang Zuokun Yang F. Murilo Zerbini Lifeng Zhai Yong-Zhen Zhang Song Zhang Jinguo Zhang Zhe Zhang Xueping ZhouAbstract
In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.
Authors
Jens H. Kuhn Scott Adkins Bernard R. Agwanda Rim Al Kubrusli Sergey V. Alkhovsky Gaya K. Amarasinghe Tatjana Avšič-Županc María A. Ayllón Justin Bahl Anne Balkema-Buschmann Matthew J. Ballinger Christopher F. Basler Sina Bavari Martin Beer Nicolas Bejerman Andrew J. Bennett Dennis A. Bente Éric Bergeron Brian H. Bird Carol D. Blair Kim R. Blasdell Dag-Ragnar Blystad Jamie Bojko Wayne B. Borth Steven Bradfute Rachel Breyta Thomas Briese Paul A. Brown Judith K. Brown Ursula J. Buchholz Michael J. Buchmeier Alexander Bukreyev Felicity Burt Carmen Büttner Charles H. Calisher Mengji Cao Inmaculada Casas Kartik Chandran Rémi N. Charrel Qi Cheng Yuya Chiaki Marco Chiapello Il-Ryong Choi Marina Ciuffo J. Christopher S. Clegg Ian Crozier Elena Dal Bó Juan Carlos de la Torre Xavier de Lamballerie Rik L. de Swart Humberto Debat Nolwenn M. Dheilly Emiliano Di Cicco Nicholas Di Paola Francesco Di Serio Ralf G. Dietzgen Michele Digiaro Olga Dolnik Michael A. Drebot J. Felix Drexler William G. Dundon W. Paul Duprex Ralf Dürrwald John M. Dye Andrew J. Easton Hideki Ebihara Toufic Elbeaino Koray Ergünay Hugh W. Ferguson Anthony R. Fooks Marco Forgia Pierre B. H. Formenty Jana Fránová Juliana Freitas-Astúa Jingjing Fu Stephanie Fürl Selma Gago-Zachert George Fú Gāo María Laura García Adolfo García-Sastre Aura R. Garrison Thomas Gaskin Jean-Paul J. Gonzalez Anthony Griffiths Tony L. Goldberg Martin H. Groschup Stephan Günther Roy A. Hall John Hammond Tong Han Jussi Hepojoki Roger Hewson Jiang Hong Ni Hong Seiji Hongo Masayuki Horie John S. Hu Tao Hu Holly R. Hughes Florian Hüttner Timothy H. Hyndman M. Ilyas Risto Jalkanen Dàohóng Jiāng Gilda B. Jonson Sandra Junglen Fujio Kadono Karia H. Kaukinen Michael Kawate Boris Klempa Jonas Klingström Gary Kobinger Igor Koloniuk Hideki Kondō Eugene V. Koonin Mart Krupovic Kenji Kubota Gael Kurath Lies Laenen Amy J. Lambert Stanley L. Langevin Benhur Lee Elliot J. Lefkowitz Eric M. Leroy Shaorong Li Longhui Li Jiànróng Lǐ Huazhen Liu Igor S. Lukashevich Piet Maes William Marciel de Souza Marco Marklewitz Sergio H. Marshall Shin-Yi L. Marzano Sebastien Massart John W. McCauley Michael Melzer Nicole Mielke-Ehret Kristina M. Miller Tobi J. Ming Ali Mirazimi Gideon J. Mordecai Hans-Peter Mühlbach Elke Mühlberger Rayapati Naidu Tomohide Natsuaki José A. Navarro Sergey V. Netesov Gabriele Neumann Norbert Nowotny Márcio R. T. Nunes Alejandro Olmedo-Velarde Gustavo Palacios Vicente Pallás Bernadett Pályi Anna Papa Sofia Paraskevopoulou Adam C. Park Colin R. Parrish David A. Patterson Alex Pauvolid-Corrêa Janusz T. Pawęska Susan Payne Carlotta Peracchio Daniel R. Pérez Thomas S. Postler Liying Qi Sheli R. Radoshitzky Renato O. Resende Carina A. Reyes Bertus K. Rima Gabriel Robles Luna Víctor Romanowski Paul Rota Dennis Rubbenstroth Luisa Rubino Jonathan A. Runstadler Sead Sabanadzovic Amadou Alpha Sall Maria S. Salvato Rosemary Sang Takahide Sasaya Angela D. Schulze Martin Schwemmle Mang Shi Xiǎohóng Shí Zhènglì Shí Yoshifumi Shimomoto Yukio Shirako Stuart G. Siddell Peter Simmonds Manuela Sironi Guy Smagghe Sophie Smither Jin-Won Song Kirsten Spann Jessica R. Spengler Mark D. Stenglein David M. Stone Jari Sugano Curtis A. Suttle Amy Tabata Ayato Takada Shigeharu Takeuchi David P. Tchouassi Amy Teffer Robert B. Tesh Natalie J. Thornburg Yasuhiro Tomitaka Keizō Tomonaga Noël Tordo Baldwyn Torto Jonathan S. Towner Shinya Tsuda Changchun Tu Massimo Turina Ioannis E. Tzanetakis Janice Uchida Tomio Usugi Anna Maria Vaira Marta Vallino Bernadette van den Hoogen Arvind Varsani Nikos Vasilakis Martin Verbeek Susanne von Bargen Jiro Wada Victoria Wahl Peter J. Walker Lin-Fa Wang Guoping Wang Yanxiang Wang Yaqin Wang Muhammad Waqas Tàiyún Wèi Shaohua Wen Anna E. Whitfield John V. Williams Yuri I. Wolf Jiangxiang Wu Lei Xu Hironobu Yanagisawa Caixia Yang Zuokun Yang F. Murilo Zerbini Lifeng Zhai Yong-Zhen Zhang Song Zhang Jinguo Zhang Zhe Zhang Xueping ZhouAbstract
No abstract has been registered