Fitness of Monilinia fructicola isolates at different levels of sensitivity to azoxystrobin

• Grant number: 13/20285-0
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): January 01, 2014
• Effective date (End): May 31, 2015
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Lilian Amorim
• Grantee: Isabela Vescove Primiano
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 14/09472-5 - Molecular characterization of Monilinia fructicola isolates with different levels of sensitivity to azoxystrobin, BE.EP.MS

Abstract

The main control of brown rot in peaches (Monilinia fructicola) is by preventive spraying of fungicides, mostly systemic. The continuous use of this pesticide has drawbacks such as the resistance of individuals to the active ingredient and, consequently, efficiency loss of the control in orchards. The population evolution of resistant strains in time can be predicted with tests on competitive ability between sensitive and resistant strains, Therefore, fitness and stability studies are necessary to check and characterize field strains to aid in anti-resistance strategies. The objective of the project is to study the competitive ability of Monilinia fructicola isolates at different levels of sensitivity to azoxystrobin in the absence of fungicide in vitro and in vivo, comparing different monocyclic components and the fitness of sensitive and resistant strains. Isolates characterization will be carried out in vitro, in vivo and molecularly. Growth rate, germination and sporulation will be estimated in vitro and disease incidence and severity and sporulation will be evaluated in peach fruit of sensitive and resistant strains individually. We will test the evolution of sensitive and resistant population mixture for five generations inoculated in peach fruit without fungicide. Sporulation data will be analyzed by analysis of variance and the Tukey test at 5% probability with ideal transformations. For data analysis, growth population models will be adjusted to brown rot incidence and severity progress rate for each isolate. Model parameters with the best adjustment will be compared using the Stundent T-test (p<0.05). Stability will be tested comparing mycelial growth, germination and sporulation of strains on nonamended and azoxystrobin-amended media after ten consecutive transfer procedures. Competitive ability will be investigated by the percentage evolution of resistant isolate in time. Linear and non-linear adjustment will be used to explain resistant isolate progress in time (transfer procedure). We intend to request a Research Scholarship (Bolsa Estágio de Pesquisa no Exterior - BEPE) to carry out molecular characterization of resistant strains, at the Gulf Coast Research and Education Center, at the University of Florida, USA, with Dr. Natália Peres. This research group has experience in resistance of fungi to fungicides. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PRIMIANO, ISABELA VESCOVE; EDWARDS MOLINA, JUAN PABLO; MAY DE MIO, LOUISE LARISSA; PERES, NATALIA APARECIDA; AMORIM, LILIAN. Reduced sensitivity to azoxystrobin is stable in Monilinia fructicola isolates. Scientia Agricola, v. 74, n. 2, p. 169-173, MAR-APR 2017. (13/20285-0)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

PRIMIANO, Isabela Vescove. Fitness of Monilinia fructicola isolates with different levels of sensitivity to azoxystrobin. 2015. Master's Dissertation - Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) Piracicaba.