Brevicoryne brassicae - Aphelinus asychis as a model for basic research on the physiological, molecular and biological mechanisms of host resistance to parasitization

• Grant number: 16/03005-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2016
• End date: December 31, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Fernando Luis Cônsoli
• Grantee: Mariane Possignolo Gomes
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

All organisms that settle interspecific pathological interactions develop defense mechanisms against pathogenic micro or macrorganism. In spite of the knowledge on the immunological responses of insects to naturals enemies, few studies are dedicated to establish the molecular bases involved in this process, as well as the heritability of such traits and the potential of their fixation in natural populations. In addition to the behavioral, genetic and physiologic mechanisms associated to host defense against natural enemies, insects harbour microrganisms that provide increased defense against entomopathogens and/or entomophages, mainly parasitoids. Therefore, the identification and characterization of host defense mechanisms to natural enemies and their potential to lead to the evolution of resistance against parasitoids are fundamental to guarantee the proper selection and use of candidate natural enemies in biological control programs. Our goal in this project is to evaluate the existence of resistance mechanisms against natural enemies by studying the model system Brevicoryne brassicae and its parasitoid Aphelinus asychis. Our study will involve the evaluation of the susceptibility of isolines from several populations of B. brassicae to the parasitization by A. asychis, including the characterization and determination of the occurrence of aphid-associated symbionts leading to increased defense against natural enemies. Isolines with increased resistance to parasitization by A. asychis will have tjeir fitness traits compared to susceptible isolines in order to investigate the existence of fitness costs associated with increased resistance to parasitoids. The established susceptible and resistant isolines will serve to future research on the physiological/molecular mechanisms involved in the increased defense to parasitoids.