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Since the potato purple top appeared and the potato psyllid was reported in Ecuador, crop losses have been significant. So far, phytoplasmas enclosed in two ribosomal groups (16SrI-F, 16SrII) and ‘Candidatus Liberibacter solanacearum’ were molecularly identified in symptomatic potato plants. Later, Bactericera cockerelli, a potato psyllid, was also first reported and correlated to the potato purple top disease. Molecular identification of the pathogens involved in this disease has been quite elusive. Samples of potato psyllids were analyzed in this study resulting in the identification of phytoplasmas enclosed in group 16SrXI, and others related to ‘Candidatus Phytoplasma prunorum’ and ‘Ca. P. solani’. Potato purple top in Ecuador is a complex disease that constitutes a severe threat for the potato production in the region.

The chrysanthemum is a popular ornamental flower all around the world for both cut flowers and potted plants. In recent days, bacterial infections are reducing in several cases its market value. Irregular flowering, yellowing and decline symptoms were observed at a commercial enterprise located in North Italy. To verify the presence of phytoplasmas, DNA was extracted from symptomatic and asymptomatic potted plants and subjected to specific polymerase chain reaction followed by restriction fragment length polymorphism analysis on phytoplasma 16S ribosomal gene. The tests were carried out three times in 7 months to verify the persistence of detected phytoplasmas over time. Phytoplasma classified in group 16SrV (elm yellows) were detected in all the examined samples independently from the presence of decline symptoms, while group 16SrXII (“stolbur”) phytoplasmas were only detected in the most severely declining plants. This latter phytoplasma strain was also characterized on tuf and leu genes by RFLP analyses and sequencing, respectively, to cross confirm its presence and identity. The detection of this phytoplasma in chrysanthemum plants is the first report in Italy, while it has already been identified in plants with malformed inflorescence in Europe, but not in other parts of the world.

Sugarcane crop is severely affected by diverse phytoplasma-associated diseases worldwide. Symptomatic sugarcane, eggplant and cluster bean together with weeds such as false daisy, Croton sparsiflorum, and Parthenium hysterophorus samples were collected at Khanapur village in Karnataka, India in 2018. The molecular analyses of the samples allowed to identify the presence of 16SrXI phytoplasma group after nested PCR amplification of the 16S rRNA gene followed by RFLP and sequencing analyses. The virtual and real RFLP analysis of the 16S rRNA gene sequence suggested its classification in a new ribosomal subgroup tentatively named 16SrXI-G. Amplification of secA and tuf genes from the sugarcane samples also confirmed the presence of 16SrXI group phytoplasmas in sugarcane and other host plant species in India and indicate their close relationship with sugarcane white leaf phytoplasmas from Sri Lanka and Vietnam. The identification of this phytoplasma strain in sugarcane, brinjal, cluster beans and weeds, in and around sugarcane fields in Karnataka, is an important information that should be employed to help the disease management aimed to reduce the phytoplasma incidence and economic losses in sugarcane.