Lav Sharma1, Irene Oliveira1,2, Fátima Gonçalves1, Fernando Raimundo1, Rupesh Kumar Singh3, Laura Torres1, Guilhermina Marques1. 1. Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (CITAB-UTAD), 5000-801 Vila Real, Portugal. 2. Centre for Computational and Stochastic Mathematics, University of Lisbon (CEMAT-IST-UL), 1049-001 Lisbon, Portugal. 3. Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal.
Abstract
Entomopathogenic fungi (EPF) contribute to different ecosystem services. However, factors affecting their natural occurrences in soil remain poorly understood. In a previous study, 81 soil samples were subjected to insect baiting using Galleria mellonella and Tenebrio molitor to isolate EPF from Portuguese vine farms. Here, soils yielding any of the four common EPF, i.e., Beauveria bassiana, Purpureocillium lilacinum, Metarhizium robertsii, and Clonostachys rosea f. rosea, were correlated with their chemical properties. Beauveria bassiana was negatively affected by higher available P (p = 0.02), exchangeable K-ions (p = 0.016) and positively affected by higher soil pH_H2O (p = 0.021). High exchangeable K-ions inhibited P. lilacinum (p = 0.011) and promoted C. rosea f. rosea (p = 0.03). Moreover, high available K also suppressed P. lilacinum (p = 0.027). Metarhizium robertsii was inhibited by higher organic matter content (p = 0.009), higher C:N (p = 0.017), total N (p = 0.007), and exchangeable Mg-ions (p = 0.026), and promoted by higher exchangeable Na-ions (p = 0.003). Nonetheless, mean comparisons and principal component analysis suggested that higher soil pH and exchangeable Ca-ions have contrasting effects on EPF occurrences, as they promote B. bassiana and inhibit M. robertsii. Herbicides did not seem to affect EPF presence. Overall, this study is among the first reports on the effects of soil chemistry on EPF other than Metarhizium, and will facilitate biological pest management approaches.
Entclass="Chemical">omoclass="Chemical">pan class="Chemical">pathogenic fungi (EPF) contribute to different ecosystem services. However, factors affecting their natural occurrences in soil remain poorly understood. In a previous study, 81 soil samples were subjected to insect baiting using Galleria mellonella and Tenebrio molitor to isolate EPF from Portuguese vine farms. Here, soils yielding any of the four common EPF, i.e., Beauveria bassiana, Purpureocillium lilacinum, Metarhizium robertsii, and Clonostachys roseaf. rosea, were correlated with their chemical properties. Beauveria bassiana was negatively affected by higher available P (p = 0.02), exchangeable K-ions (p = 0.016) and positively affected by higher soil pH_H2O (p = 0.021). High exchangeable K-ions inhibited P. lilacinum (p = 0.011) and promoted C. roseaf. rosea (p = 0.03). Moreover, high available K also suppressed P. lilacinum (p = 0.027). Metarhizium robertsii was inhibited by higher organic matter content (p = 0.009), higher C:N (p = 0.017), total N (p = 0.007), and exchangeable Mg-ions (p = 0.026), and promoted by higher exchangeable Na-ions (p = 0.003). Nonetheless, mean comparisons and principal component analysis suggested that higher soil pH and exchangeable Ca-ions have contrasting effects on EPF occurrences, as they promote B. bassiana and inhibit M. robertsii. Herbicides did not seem to affect EPF presence. Overall, this study is among the first reports on the effects of soil chemistry on EPF other than Metarhizium, and will facilitate biological pest management approaches.
Authors: Belén Cotes; Linda-Marie Rännbäck; Maria Björkman; Hans Ragnar Norli; Nicolai V Meyling; Birgitta Rämert; Peter Anderson Journal: Oecologia Date: 2015-05-07 Impact factor: 3.225