Evidência molecular da ocorrência de fitoplasma associado ao superbrotamento do maracujazeiro em cinco estados brasileiros

Abstract

Phytoplasmas are cell wall-less prokaryotes and phloem-inhabitants associated with diseases that affect several crops. Passion fruit is a tropical plant species cultivated in various Brazilian regions. Diseases are among the factors that may cause damage to this crop, and witches' broom is a very important one. This disease, associated with a phytoplasma, has been reported only in Brazil, where it was described in Rio de Janeiro and Pernambuco States at the beginning of the 1980's. In 2005-2006, symptomatic plants suspected of phytoplasma infection were sampled in areas located in São Paulo, Paraná, Rio de Janeiro, Sergipe and Bahia. Amplification of DNA fragments of 1.2kb from nested PCR primed by the pairs 16mF2/mRl and 16F2n/R2 revealed the presence of phytoplasma in the tissue of plants from all sampled regions. Molecular detection of the agent allowed confirmation of the diagnosis based on the symptomatology; demonstrated the strong association between diseased plants and a phytoplasma, confirming previous investigations based on electron microscopy; and revealed the present occurrence of the agent in the States of Bahia, Paraná, Rio de Janeiro, Sergipe, and São Paulo. Copyright by the Brazilian Phytopathological Society.