Morphological and pathogenic variability of Austropuccinia psidii isolates from different hosts

• Grant number: 20/10117-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2020
• End date: August 31, 2021
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Lilian Amorim
• Grantee: João Vitor Pelizzaro Morales
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 19/13191-5 - Epidemiological components, damage characterization and control of tropical and temperate rusts at a global climate change scenario, AP.TEM

Abstract

Myrtle rust is a typical tropical disease, caused by Austropuccinia psidii. Myrtle rust has been well described in eucalyptus, but very little information is available on this disease in other hosts of the Myrtaceae family. Intraspecific diversity has already been observed when isolates of A. psidii from eucalyptus were inoculated in guava plants and vice-versa. However, in this project, the objective is to verify intraspecific diversity in A. psidii populations from guava (Psidium guajava), rose apple (Syzygium jambos) and cherry of the Rio Grande (Eugenia involucrata). To verify the intraspecific diversity of A. psidii, monopustular isolates will be obtained from uredinospores of symptomatic leaves of guava, rose apple and cherry of the Rio Grande. Four monopustular isolates from each host will be selected for morphological and pathogenic characterization. In the morphological analysis, the size, shape and color of urediniospores will be assessed by light microscopy and the frequency and shape of urediniospores ornamentation will be assessed by scanning electron microscopy. In the pathogenic analysis isolates will be inoculated in all hosts and monocyclic components of the disease will be evaluated and compared.