Beatriz Andreo-Jimenez1, Mirjam T Schilder1, Els H Nijhuis1, Dennis E Te Beest2, Jaap Bloem3, Johnny H M Visser4, Gera van Os5, Karst Brolsma6, Wietse de Boer7,8, Joeke Postma9. 1. Biointeractions & Plant Health, Wageningen University & Research, Wageningen, The Netherlands. 2. Biometris, Wageningen University & Research, Wageningen, The Netherlands. 3. Animal Ecology, Wageningen University & Research, Wageningen, The Netherlands. 4. Field Crops, Wageningen University & Research, Wageningen, The Netherlands. 5. Aeres University of Applied Sciences, Dronten, The Netherlands. 6. Eurofins Agro, Wageningen, The Netherlands. 7. Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, The Netherlands. 8. Soil Biology Group, Wageningen University & Research, Wageningen, The Netherlands. 9. Biointeractions & Plant Health, Wageningen University & Research, Wageningen, The Netherlands joeke.postma@wur.nl.
Abstract
Enhancing soil suppressiveness against plant pathogens or pests is a promising alternative strategy to chemical pesticides. Organic amendments have been shown to reduce crop diseases and pests, with chitin products the most efficient against fungal pathogens. To study which characteristics of organic products are correlated with disease suppression, an experiment was designed in which 10 types of organic amendments with different physicochemical properties were tested against the soilborne pathogen Rhizoctonia solani in sugar beet seedlings. Organic amendments rich in keratin or chitin reduced Rhizoctonia solani disease symptoms in sugar beet plants. The bacterial and fungal microbial communities in amended soils were distinct from the microbial communities in nonamended soil, as well as those in soils that received other nonsuppressive treatments. The Rhizoctonia-suppressive amended soils were rich in saprophytic bacteria and fungi that are known for their keratinolytic and chitinolytic properties (i.e., Oxalobacteraceae and Mortierellaceae). The microbial community in keratin- and chitin-amended soils was associated with higher zinc, copper, and selenium, respectively.IMPORTANCE Our results highlight the importance of soil microorganisms in plant disease suppression and the possibility to steer soil microbial community composition by applying organic amendments to the soil.
Enhancing sn class="Chemical">oiln> suppressiveness against plant pathogens or pests is a promising alternative strategy to chemical pesticides. Organic amendments have been shown to reduce crop diseases and pests, with chitin products the most efficient against fungal pathogens. To study which characteristics of organic products are correlated with disease suppression, an experiment was designed in which 10 types of organic amendments with different physicochemical properties were tested against the soilborne pathogen Rhizoctonia solani in sugar beetseedlings. Organic amendments rich in keratin or chitinreduced Rhizoctonia solani disease symptoms in sugar beet plants. The bacterial and fungal microbial communities in amended soils were distinct from the microbial communities in nonamended soil, as well as those in soils that received other nonsuppressive treatments. The Rhizoctonia-suppressive amended soils were rich in saprophytic bacteria and fungi that are known for their keratinolytic and chitinolytic properties (i.e., Oxalobacteraceae and Mortierellaceae). The microbial community in keratin- and chitin-amended soils was associated with higher zinc, copper, and selenium, respectively.IMPORTANCE Our results highlight the importance of soil microorganisms in plant disease suppression and the possibility to steer soil microbial community composition by applying organic amendments to the soil.
Authors: Anna Clocchiatti; Silja Emilia Hannula; Muhammad Syamsu Rizaludin; Maria P J Hundscheid; Paulien J A Klein Gunnewiek; Mirjam T Schilder; Joeke Postma; Wietse de Boer Journal: Microorganisms Date: 2021-06-12