A new protection approach with mild strains for an attempt to control the woodiness disease of passion fruit fruits by premunization

• Grant number: 23/16625-1
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2024
• End date: April 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Jorge Alberto Marques Rezende
• Grantee: Jorge Alberto Marques Rezende
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 24/07618-4 - Application of reverse genetics for the selection of mild strains of the virus of the passion fruit woodiness to attempt to control the disease by pre-immunization, BP.TT

Abstract

The woodiness disease of passion fruit, caused by the potyvirus cowpea aphid-borne mosaic virus (CABMV), transmitted by aphids in a non-persistent manner, is the most critical and limiting disease in the cultivation of this fruit tree. Controlling passion fruit woodiness disease is difficult, mainly because commercially exploited Passiflora species are not resistant to the virus or tolerant to the disease. Several disease control strategies have already been evaluated but have yet to achieve the expected success. Among them are the use of mild strains of the virus for pre-immunization (cross-protection) and the identification of genotypes of Passiflora spp. resistant to CABMV or tolerant to the disease, and the use of resistance derived from the pathogen through transgenic passion fruit plants with the CABMV capsid protein gene. Cultural practices have been recommended to increase crop longevity, including the systematic eradication (roguing) of diseased passion fruit plants within five months after transplantation. Given the lack of an efficient and permanent method for managing this disease and the robust results of the efficient use of mixtures of mild strains to control tomato mosaic caused by pepino mosaic virus in Europe, it is opportune to return to the problem that severely affects the passion fruit production in Brazil with a new approach for the selection and evaluation of the protection of mild strains of the virus. Initially, the genetic and biological variability of CABMV isolates from different geographic regions of Brazil that cultivate this passifloraceae will be studied. Attempts will be made sequentially to isolate mild strains from the available isolates using biological and molecular methods. Finally, the protection of passion fruit plants will be evaluated when inoculated with mixtures of mild virus strains under greenhouse conditions and, if possible, begin field evaluations. (AU)