Production of Microsclerotia From Entomopathogenic Fungi and Use in Maize Seed Coating as Delivery for Biocontrol Against Fusarium graminearum

Frontiers in Sustainable Food Systems

Trevor A. Jackson¹  Michael Rostás²  Travis R. Glare²  John G. Hampton²  Per Wessman³  Jayanthi Swaminathan⁴  Federico Rivas-Franco⁵  Nora A. Altier⁵  David J. Saville⁶  Mark A. Jackson⁷ 

[1] AgResearch, Lincoln Research Center, Lincoln, New Zealand;Bio-Protection Research Center, Lincoln University, Lincoln, New Zealand;Department Chemical Process and Pharmaceutical Development, Unit Formulation, Research Institute of Sweden (RISE), Borås, Sweden;Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand;Plataforma de Bioinsumos, Programa de Producción y Sustentabilidad Ambiental, Instituto Nacional de Investigación Agropecuaria (INIA), INIA - Las Brujas, Canelones, Uruguay;Saville Statistical Consulting Limited, Lincoln, New Zealand;United States Department of Agriculture (USDA), National Center for Agricultural Utilization, Peoria, IL, United States;

关键词: plant growth promotion;    microsclerotia;    plant protection;    Metarhizium spp;    Fusarium graminearum;    seed coating;   

DOI  :  10.3389/fsufs.2020.606828

来源: DOAJ

【 摘 要 】

The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained more interest since the discovery that several species of this genus are able to colonize roots. In general, commercial products with Metarhizium are formulated based on conidia for insect pest control. The process of mass production, harvesting, and formulation of infective conidia can be detrimental for conidial viability. Entomopathogenic fungi such as Metarhizium spp. are able to produce high concentrations of resistant structures, known as microsclerotia, when grown in liquid media. Microsclerotia are desiccation tolerant, with excellent storage stability, and are capable of producing high quantities of infective conidia after rehydration. The aim of this study was to evaluate microsclerotia production by different isolates of Metarhizium spp. and determine the effect of microsclerotia coated onto maize seeds on plant growth in the presence of soil-borne pathogen Fusarium graminearum. On average, ~1 × 105 microsclerotia/mL were produced by selected isolates of M. anisopliae (A1080 and F672) and Metarhizium robertsii (F447). Microsclerotia were formulated as granules with diatomaceous earth and used for seed coating, after which propagules produced around 5 × 106 CFU/g of seeds. In the presence of the plant pathogen, maize plants grown from untreated seeds had the lowest growth, while plants treated with the Metarhizium microsclerotia had significantly greater growth than the control plants. Hyphae were observed growing on and in root tissues in all the Metarhizium spp. treatments but not in samples from control plants. Metarhizium hyphal penetration points' on roots were observed 1 month after sowing, indicating the fungi were colonizing roots as endophytes. The results obtained indicate that microsclerotia can be coated onto seeds, providing plant protection against soil plant pathogens and a method to establish Metarhizium in the ecto- and endo-rhizosphere of maize roots, allowing the persistence of this biocontrol agent.

【 授权许可】

Unknown