Chapitre 14: Phytopathogènes et stratégies de contrôle en aquaponie

peer reviewedAmong the diversity of plant diseases occurring in aquaponics, soil-borne pathogens, such as Fusarium spp., Phytophthora spp. and Pythium spp., are the most problematic due to their preference for humid/aquatic environment conditions. Phytophthora spp. and Pythium spp. which belong to the Oomycetes pseudo-fungi require special attention because of their mobile form of dispersion, the so-called zoospores that can move freely and actively in liquid water. In coupled aquaponics, curative methods are still limited because of the possible toxicity of pesticides and chemical agents for fish and beneficial bacteria (e.g. nitrifying bacteria of the biofilter). Furthermore, the development of biocontrol agents for aquaponic use is still at its beginning. Consequently, ways to control the initial infection and the progression of a disease are mainly based on preventive actions and water physical treatments. However, suppressive action (suppression) could happen in aquaponic environment considering recent papers and the suppressive activity already highlighted in hydroponics. In addition, aquaponic water contains organic matter that could promote establishment and growth of heterotrophic bacteria in the system or even improve plant growth and viability directly. With regards to organic hydroponics (i.e. use of organic fertilisation and organic plant media), these bacteria could act as antagonist agents or as plant defence elicitors to protect plants from diseases. In the future, research on the disease suppressive ability of the aquaponic biotope must be increased, as well as isolation, characterisation and formulation of microbial plant pathogen antagonists. Finally, a good knowledge in the rapid identification of pathogens, combined with control methods and diseases monitoring, as recommended in integrated plant pest management, is the key to an efficient control of plant diseases in aquaponics.Cos

Pathogenic and beneficial microorganisms in soilless cultures

Soilless cultures were originally developed to control soilborne diseases. Soilless cultures provide several advantages for growers such as greater production of crops, reduced energy consumption, better control of growth and independence of soil quality. However, diseases specific to hydroponics have been reported. For instance, zoospore-producing microorganisms such as Pythium and Phytophthora spp. are particularly well adapted to aquatic environments. Their growth in soilless substrates is favoured by the recirculation of the nutrient solution. These pathogenic microorganisms are usually controlled by disinfection methods but such methods are only effective as a preventive measure. Contrary to biofiltration, active treatments such as UV, heat and ozonisation have the disadvantage of eliminating not only the harmful microorganisms but also the beneficial indigenous microorganisms. Here, we review microbial populations that colonise ecological niches of hydroponic greenhouse systems. Three topics are discussed: (1) the general microflora; (2) the pathogenic microflora that are typical to hydroponic systems; and (3) the non-pathogenic and possibly beneficial microflora, and their use in the control of plant diseases in soilless greenhouse systems. Technical, economic and environmental concerns are forcing the adoption of new sustainable methods such as the use of microbial antagonists. Thus, increased attention is now focused on the role of natural microflora in suppressing certain diseases. Managing disease suppression in hydroponics represents a promising way of controlling pathogens. Three main strategies can be used: (1) increasing the level of suppressiveness by the addition of antagonistic microorganisms; (2) using a mix of microorganisms with complementary ecological traits and antagonistic abilities, combined with disinfection techniques; and (3) amending substrates to favour the development of a suppressive microflora. Increasing our knowledge on beneficial microflora, their ecology and treatments that influence their composition will help to commercialise new, ready-to-use substrates microbiologically optimised to protect plants in sustainable management systems

Fungal Planet description sheets: 716–784

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetopsina eucalypti on Eucalyptus leaf litter, Colletotrichum cobbittiense from Cordyline stricta × C. australis hybrid, Cyanodermella banksiae on Banksia ericifolia subsp. macrantha, Discosia macrozamiae on Macrozamia miquelii, Elsinoë banksiigena on Banksia marginata, Elsinoë elaeocarpi on Elaeocarpus sp., Elsinoë leucopogonis on Leucopogon sp., Helminthosporium livistonae on Livistona australis, Idriellomyces eucalypti (incl. Idriellomyces gen. nov.) on Eucalyptus obliqua, Lareunionomyces eucalypti on Eucalyptus sp., Myrotheciomyces corymbiae (incl. Myrotheciomyces gen. nov., Myrotheciomycetaceae fam. nov.), Neolauriomyces eucalypti (incl. Neolauriomyces gen. nov., Neolauriomycetaceae fam. nov.) on Eucalyptus sp., Nullicamyces eucalypti (incl. Nullicamyces gen. nov.) on Eucalyptus leaf litter, Oidiodendron eucalypti on Eucalyptus maidenii, Paracladophialophora cyperacearum (incl. Paracladophialophoraceae fam. nov.) and Periconia cyperacearum on leaves of Cyperaceae, Porodiplodia livistonae (incl. Porodiplodia gen. nov., Porodiplodiaceae fam. nov.) on Livistona australis, Sporidesmium melaleucae (incl. Sporidesmiales ord. nov.) on Melaleuca sp., Teratosphaeria sieberi on Eucalyptus sieberi, Thecaphora australiensis in capsules of a variant of Oxalis exilis. Brazil, Aspergillus serratalhadensis from soil, Diaporthe pseudoinconspicua from Poincianella pyramidalis, Fomitiporella pertenuis on dead wood, Geastrum magnosporum on soil, Marquesius aquaticus (incl. Marquesius gen. nov.) from submerged decaying twig and leaves of unidentified plant, Mastigosporella pigmentata from leaves of Qualea parviflorae, Mucor souzae from soil, Mycocalia aquaphila on decaying wood from tidal detritus, Preussia citrullina as endophyte from leaves of Citrullus lanatus, Queiroziella brasiliensis (incl. Queiroziella gen. nov.) as epiphytic yeast on leaves of Portea leptantha, Quixadomyces cearensis (incl. Quixadomyces gen. nov.) on decaying bark, Xylophallus clavatus on rotten wood. Canada, Didymella cari on Carum carvi and Coriandrum sativum. Chile, Araucasphaeria foliorum (incl. Araucasphaeria gen. nov.) on Araucaria araucana, Aspergillus tumidus from soil, Lomentospora valparaisensis from soil. Colombia, Corynespora pseudocassiicola on Byrsonima sp., Eucalyptostroma eucalyptorum on Eucalyptus pellita, Neometulocladosporiella eucalypti (incl. Neometulocladosporiella gen. nov.) on Eucalyptus grandis × urophylla, Tracylla eucalypti (incl. Tracyllaceae fam. nov., Tracyllalales ord. nov.) on Eucalyptus urophylla. Cyprus, Gyromitra anthracobia (incl. Gyromitra subg. Pseudoverpa) on burned soil. Czech Republic, Lecanicillium restrictum from the surface of the wooden barrel, Lecanicillium testudineum from scales of Trachemys scripta elegans. Ecuador, Entoloma yanacolor and Saproamanita quitensis on soil. France, Lentithecium carbonneanum from submerged decorticated Populus branch. Hungary, Pleuromyces hungaricus (incl. Pleuromyces gen. nov.) from a large Fagus sylvatica log. Iran, Zymoseptoria crescenta on Aegilops triuncialis. Malaysia, Ochroconis musicola on Musa sp. Mexico, Cladosporium michoacanense from soil. New Zealand , Acrodontium metrosideri on Metrosideros excelsa, Polynema podocarpi on Podocarpus totara, Pseudoarthrographis phlogis (incl. Pseudoarthrographis gen. nov.) on Phlox subulata. Nigeria, Coprinopsis afrocinerea on soil. Pakistan, Russula mansehraensis on soil under Pinus roxburghii. Russia, Baorangia alexandri on soil in deciduous forests with Quercus mongolica. South Africa, Didymocyrtis brachylaenae on Brachylaena discolor. Spain, Alfaria dactylis from fruit of Phoenix dactylifera, Dothiora infuscans from a blackened wall, Exophiala nidicola from the nest of an unidentified bird, Matsushimaea monilioides from soil, Terfezia morenoi on soil. United Arab Emirates, Tirmania honrubiae on soil. USA, Arxotrichum wyomingense (incl. Arxotrichum gen. nov.) from soil, Hongkongmyces snookiorum from submerged detritus from a fresh water fen, Leratiomyces tesquorum from soil, Talaromyces tabacinus on leaves of Nicotiana tabacum. Vietnam, Afroboletus vietnamensis on soil in an evergreen tropical forest, Colletotrichum condaoense from Ipomoea pes-caprae. Morphological and culture characteristics along with DNA barcodes are provided

Fungal Planet description sheets: 716–784

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetopsina eucalypti on Eucalyptus leaf litter, Colletotrichum cobbittiense from Cordyline stricta × C. australis hybrid, Cyanodermella banksiae on Banksia ericifolia subsp. macrantha, Discosia macrozamiae on Macrozamia miquelii, Elsinoë banksiigena on Banksia marginata, Elsinoë elaeocarpi on Elaeocarpus sp., Elsinoë leucopogonis on Leucopogon sp., Helminthosporium livistonae on Livistona australis, Idriellomyces eucalypti (incl. Idriellomyces gen. nov.) on Eucalyptus obliqua, Lareunionomyces eucalypti on Eucalyptus sp., Myrotheciomyces corymbiae (incl. Myrotheciomyces gen. nov., Myrotheciomycetaceae fam. nov.), Neolauriomyces eucalypti (incl. Neolauriomyces gen. nov., Neolauriomycetaceae fam. nov.) on Eucalyptus sp., Nullicamyces eucalypti (incl. Nullicamyces gen. nov.) on Eucalyptus leaf litter, Oidiodendron eucalypti on Eucalyptus maidenii, Paracladophialophora cyperacearum (incl. Paracladophialophoraceae fam. nov.) and Periconia cyperacearum on leaves of Cyperaceae, Porodiplodia livistonae (incl. Porodiplodia gen. nov., Porodiplodiaceae fam. nov.) on Livistona australis, Sporidesmium melaleucae (incl. Sporidesmiales ord. nov.) on Melaleuca sp., Teratosphaeria sieberi on Eucalyptus sieberi, Thecaphora australiensis in capsules of a variant of Oxalis exilis. Brazil, Aspergillus serratalhadensis from soil, Diaporthe pseudoinconspicua from Poincianella pyramidalis, Fomitiporella pertenuis on dead wood, Geastrum magnosporum on soil, Marquesius aquaticus (incl. Marquesius gen. nov.) from submerged decaying twig and leaves of unidentified plant, Mastigosporella pigmentata from leaves of Qualea parviflorae, Mucor souzae from soil, Mycocalia aquaphila on decaying wood from tidal detritus, Preussia citrullina as endophyte from leaves of Citrullus lanatus, Queiroziella brasiliensis (incl. Queiroziella gen. nov.) as epiphytic yeast on leaves of Portea leptantha, Quixadomyces cearensis (incl. Quixadomyces gen. nov.) on decaying bark, Xylophallus clavatus on rotten wood.Canada, Didymella cari on Carum carvi and Coriandrum sativum. Chile, Araucasphaeria foliorum (incl. Araucasphaeria gen. nov.) on Araucaria araucana, Aspergillus tumidus from soil, Lomentospora valparaisensis from soil. Colombia, Corynespora pseudocassiicola on Byrsonima sp., Eucalyptostroma eucalyptorum on Eucalyptus pellita, Neometulocladosporiella eucalypti (incl. Neometulocladosporiella gen. nov.) on Eucalyptus grandis × urophylla, Tracylla eucalypti (incl. Tracyllaceae fam. nov., Tracyllalales ord. nov.) on Eucalyptus urophylla. Cyprus, Gyromitra anthracobia (incl. Gyromitra subg. Pseudoverpa) on burned soil. Czech Republic, Lecanicillium restrictum from the surface of the wooden barrel, Lecanicillium testudineum from scales of Trachemys scripta elegans. Ecuador, Entoloma yanacolor and Saproamanita quitensis on soil. France, Lentithecium carbonneanum from submerged decorticated Populus branch. Hungary, Pleuromyces hungaricus (incl. Pleuromyces gen. nov.) from a large Fagus sylvatica log. Iran, Zymoseptoria crescenta on Aegilops triuncialis. Malaysia, Ochroconis musicola on Musa sp. Mexico, Cladosporium michoacanense from soil. New Zealand , Acrodontium metrosideri on Metrosideros excelsa, Polynema podocarpi on Podocarpus totara, Pseudoarthrographis phlogis (incl. Pseudoarthrographis gen. nov.) on Phlox subulata. Nigeria, Coprinopsis afrocinerea on soil. Pakistan, Russula mansehraensis on soil under Pinus roxburghii. Russia, Baorangia alexandri on soil in deciduous forests with Quercus mongolica. South Africa, Didymocyrtis brachylaenae on Brachylaena discolor. Spain, Alfaria dactylis from fruit of Phoenix dactylifera, Dothiora infuscans from a blackened wall, Exophiala nidicola from the nest of an unidentified bird, Matsushimaea monilioides from soil, Terfezia morenoi on soil. United Arab Emirates, Tirmania honrubiae on soil. USA, Arxotrichum wyomingense (incl. Arxotrichum gen. nov.) from soil, Hongkongmyces snookiorum from submerged detritus from a fresh water fen, Leratiomyces tesquorum from soil, Talaromyces tabacinus on leaves of Nicotiana tabacum. Vietnam, Afroboletus vietnamensis on soil in an evergreen tropical forest, Colletotrichum condaoense from Ipomoea pes-caprae. Morphological and culture characteristics along with DNA barcodes are provided.The study of Olga V. Morozova and Tatiana Yu. Svetasheva was carried out within the framework of an institutional research project of the Komarov Botanical Institute RAS ‘Biodiversity and spatial structure of fungi and myxomycetes communities in natural and anthropogenic ecosystems’ (АААА-А18-118031290108-6) using equipment of its Core Facility Center ‘Cell and Molecular Technologies in Plant Science’. Alina V. Alexandrova acknowledges financial support from the Russian Science Foundation (project N 14-50-00029).Daniela de A. Viana Marques acknowledges Universidade de Pernambuco for financial support. Jan Borovička is thanked for providing the Portuguese collection of Baorangia emileorum and its ITS and LSU sequences, and Alessia Tatti for sending the Sardinian collections of B. emileorum. Taimy Cantillo, Luis F.P. Gusmão, Luana T. do Carmo, Lucas B. Conceição, Julieth O. Sousa, Luiz F. de Oliveira, Renan N. Barbosa, Rhudson H.S.F. Cruz, André L.C.M. de A. Santiago, Carlos A.F. de Souza, Diogo X. Lima, Rafael J.V. de Oliveira and Thalline R.L. Cordeiro, Olinto L. Pereira, Rejane M.F. Silva, Rafael J.V. Oliveira, José L. Bezerra, Gladstone A. Silva Ciro R. Félix, Melissa F. Landell, Thays G.L. Oliveira, Jadson D.P. Bezerra, Alexandre R. Machado, Cristina M. Souza-Motta and Oliane M. C. Magalhães, Tatiana B. Gibertoni, Vitor Xavier de Lima and José R. C. Oliveira-Filho acknowledge financial support and/or scholarships from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), the Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq) and the Fundação de Amparo à Ciência e Tecnologia de Pernambuco (FACEPE); the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG), the Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), Parque Memorial Zumbi dos Palmares and Usina Caeté – Grupo Carlos Lyra and Nordesta AS for suport during field trips.Maria E. Ordoñez and colleagues acknowledge the Secretaria de Educación Superior, Ciencia, Tecnología e Innovación del Ecuador (SENESCYT), Arca de Noé Initiative, and the Pontificia Universidad Católica del Ecuador, project N13415 for financial support. Hugo Madrid was partially funded by Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), Chile, project no. 11140562. Vit Hubka and colleagues express their gratitude to Marek Kiecoň, Pavel Malík and Tereza Krasnokutská (National Heritage Institute) for providing information on archaeological research; Hana Rajhelová (Silesian University in Opava) and Jitka Koubková (Veterinary Laboratory Labvet) for providing photo documentation and material for mycological examinations; Czechoslovak Microscopy Society for support (CSMS scholarship 2016). The research of V. Hubka was supported by Charles University Research Centre program No. 204069 and the grant of the Czech Ministry of Health (AZV 17-31269A). Alfredo Vizzini and colleagues thank Jan Holec for administering of the loan of European material from PRM herbarium (Prague, Czech Republic). Soňa Jančovičová helped with the line drawings. Jozef Šibík and David Cooper are acknowledged for the support during the field collections in Colorado (USA) that was financed by the Slovak American Foundation.The sequencing of samples was funded by the Slovak national project Vega 02/0018/18. Željko Jurjević acknowledges Filomena Epifani and Sammy Sedky for their excellent technical support. Malka Saba acknowledges the Higher Education Commission (HEC), Islamabad, Pakistan, for financial assistance during field trips in Pakistan and the Slovak national project APVV-15-0210 for sequencing of Russula mansehraensis. The research of Alena Nováková and Miroslav Kolařík was supported by the Ministry of Education, Youth and Sports of the Czech Republic (grant number LO1509). Asunción Morte, Juan Julián Bordallo and Antonio Rodríguez were supported by projects 19484/PI/14 (FEDER and Fundación Séneca - Agencia de Ciencia y Tecnología de la Región de Murcia, Spain) and CGL2016-78946-R (AEI and FEDER, UE); they also thank Aurelio Garcia Blanco, Andries Gouws, Tom de Wet, Ali Hassan and Faisal Abdullab for their observations and assistance with field work. Daniel B. Raudabaugh and colleagues thank the Commonwealth of Pennsylvania, Pennsylvania Department of Conservation and Natural Resources, Pennsylvania Bureau of State Parks, and Black Moshannon State Park for research support, the Mycological Society of America and University of Illinois Urbana-Champaign School of Integrative Biology for financial support, and Michael Woodley for field support. Cheryl Armstrong-Cho and Sabine Banniza acknowledge funding and support by the Saskatchewan Ministry of Agriculture, the Western Grains Research Foundation, the Herb, Spice and Specialty Agriculture Association and the Saskatchewan Crop Insurance Corporation. Shuming Luo and colleagues thank Mui-keng Tan for helpful advice during this study.Peer reviewe