Sousa, Esmeraldina Agostinho NascimentoMexia, António Maria MarquesMarques, Ana Isabel Ambrósio2012-03-202012-03-202011Marques, Ana Isabel Ambrósio - Pesquisa de fitoplasmas das pomóideas e prunóideas em Portugal. Lisboa: ISA, 2011http://hdl.handle.net/10400.5/4117Mestrado em Engenharia Agronómica - Protecção das Plantas - Instituto Superior de AgronomiaPhytoplasmas are unicellular organisms, prokaryotes, cell wall-less that cause diseases in hundreds vegetable species. This study is mainly about the prospection of “Candidatus” phytoplasma pyri, “Candidatus” phytoplasma mali and “Candidatus” phytoplasma prunorum, etiologic agents of PD, AP e ESFY, vectored by psyllids Cacopsylla pyri, Cacopsylla picta e Cacopsylla pruni, respectively. These three phytoplasmas belong to AP or 16SrX group, considered quarantine organisms (A2 list, EPPO). In this study, two DNA extraction methods as well as two identification methods using PCR were compared. The two extraction methods differ in lyses buffer which seems to be crucial to obtain high quality DNA. The most used identification method until recently is nested-PCR but as it is a time consuming and expensive method, it’s being replaced by realtime PCR a quicker, more viable and less expensive one, as it was conf irmed in this study. Plant and insect samples from pome and prunus fruit trees in Oeste area were analysed. With major importance lies the fact that, for the first time, we report the presence of “Candidatus” phytoplasma pyri in insect and plant samples.porphytoplasmas16SrX grouppsyllidsnested-PCRreal-time PCRCandidatusphytoplasma pyrimaster thesis