Levantamento e diagnóstico das principais doenças que ocorrem em orquídeas (Orchidaceae) provenientes das regiões de Campina Grande e brejo paraibano.

Abstract

Orchids are ornamental plants that most call consumer attention for its unique and diverse beauties. The orchid cultivation moves a significant numbers market with plants of certain species reaching high market value. Diseases of orchids represent a major problem for producers and growers, and in Brazil, the main diseases found in orchids are caused by viruses and fungi. Therefore, this study aimed to carry out a survey and diagnose the main disease-causing pathogens in orchids in microregions of Campina Grande and the Brejo Paraibano. For this, ten samples of seven different species of orchids were collected and analyzed from the observation of symptoms, biological tests, morphological and molecular tests. By observing the symptoms of the samples, it was possible to identify yeast infection, viruses and mixed infections proving the presence of these pathogens in the plant. As biological testing, the mechanical inoculation was performed via the plant extract, where in the course of 5 days was not possible to view the symptomatology which would conclusively prove whether or not the virus infection in those samples, and thus require more molecular or serological tests e.g. , to confirm infection. In the morphological characterization, hyaline spores was observed, unicellular and fusiform ellipsoid confirming the presence of the fungus Colletotrichum different species of orchids. Molecular characterization of specific primers for the diagnosis of anthracnose caused by Colletotrichum gloeosporioides were used in the PCR. The results were positive for Orchid Cattleya Labiata species rubra. With new results, this study has contributed to direct future studies on these pathogens in orchids in the region, thus preventing the proliferation of these pathogens and consequnte species loss.