Cactus pear plants showing proliferation and stunting of cladodes in Californian cultivations were tested in order to define a molecular
methodology for reliable phytoplasma detection. After several unsuccessful trials a simple extraction method was developed
to reduce the mucilage content in nucleic acid preparations that was seriously affecting pathogen detection. Nested PCR on
16S ribosomal gene and RFLP analyses together with sequencing of obtained amplicons allow to verify the presence in symptomatic
plants of 16SrV-A and 16SrI-B phytoplasmas respectively related to \u2018Candidatus Phytoplasma ulmi\u2019 and \u2018Ca. P. asteris\u2019
