Brocolis and cauliflower stunt: phytoplasmas identification, potencial vectors, alternative hosts and epidemiological analisys of the disease

• Grant number: 10/51709-1
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2010
• End date: June 30, 2013
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Ivan Paulo Bedendo
• Grantee: Ivan Paulo Bedendo
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

An anomaly, induced by an agent recently identified, has occurred with high incidence in crops of broccolis (70-100%) and cauliflower (30-70%), causing reduction on the yield and quality of commercial products. In some locations, due the losses, fields are leaved or those crops are replaced by others vegetable species. The symptoms and previous investigations have pointed to the association of phytoplasmas with that anomaly. Thus, the present project aims to identify phytoplasmas associated with diseased plants of broccolis and cauliflower; to demonstrate the presence of probable vectors; to evaluate some species of weeds as hosts for phytoplasmas; and to study the spatial distribution of the disease in fields. The PCR technique will be used to detect phytoplasmas in the tissue of plants. The identification and phylogenetic analysis will be conduct by using RFLP analysis and sequencing of the bases present in the 16S rDNA. Diseased and asymptomatic plants will be evaluated and submitted to epidemiological models to show the distribution of the disease in the areas. Insects more frequently found in the crops will be tested for the presence of phytoplasmas in their tissues and transmission assays. Weeds will be sampled within the crops and adjacent areas and submitted to PCR in order to detect phytoplasmas. Preliminary results are promising and evidenced good possibility to obtain success in relation to the objectives of the present project. The expected results will can to bring significant contributions to the subject, which will permit to improve the understanding about the interaction hosts-pathogen-vectors. Those results will be useful to elaborate strategies for the control of the disease. (AU)