Detection and molecular characterisation of a group 16SrIX phytoplasma infecting citrus (Citrus sinensis and C. limon), coffee (Coffea arabica), periwinkle (Catharanthus roseus), and tabebuia (Tabebuia heterophylla) in Puerto Rico

Abstract

Detection and molecular characterisation of a group 16SrIX phytoplasma infecting citrus (Citrus sinensis and C. limon), coffee (Coffea arabica), periwinkle (Catharanthus roseus), and tabebuia (Tabebuia heterophylla) in Puerto Rico Abstract Few studies have determined the presence of phytoplasmas in important crops in Puerto Rico. Disease symptoms resembling those caused by phytoplasmas were observed in pigeon pea (Cajanus cajan), periwinkle (Catharanthus roseus), tabebuia (Tabebuia heterophylla), Spanish lime (Melicoccus bijugatus), ixora (Ixora coccinea), mango (Mangifera indica), cactus (Opuntia spp.), citrus trees (Citrus spp.), and coffee (Coffea arabica). Sixty-two samples from these species were tested using conventional PCR to amplify the 16S rRNA and ribosomal protein genes (rpIVrpsC). Fifty-one percent of the tested samples (corresponding to periwinkle, pigeon pea, citrus, coffee and tabebuia) were positive for phytoplasmas, with amplicons of 0.8 (16S rRNA gene) and 1.2 kb (rpIV-rpsC genes), depending upon primers used in PCRs. For both genetic loci, DNA sequences showed 99 % identity with pigeon pea witches' broom phytoplasma (PPWB). Due to the lack of studies of potential insect vectors, common Auchenorrhyncha species were sweep-collected from pigeon pea and citrus and tested for phytoplasma. Of nine insect genera collected, Empoasca kraemeri (Cicadellidae), Melormenis antillarum (Flatidae), and Colpoptera maculifrons (Issidae) were positive for PPWB based on results from conventional PCR and DNA sequence analysis. The findings indicate that these insects fed upon the aforementioned plant species, ingesting contents of phloem, and may act as potential phytoplasma vectors in the field. These are first reports of PPWB phytoplasma infections in citrus species (C. sinensis and C. limon), coffee, periwinkle and tabebuia, and in insects (E. kraemeri, M. antillarum and C. maculifrons) for Puerto Rico.

Catharanthus roseus (Apocynaceae) naturally infected with diverse phytoplasmas in Costa Rica

“…The symptoms in both geographic locations are consistent with those previously reported for the host and subgroup 16SrIX-A, such as virescence and yellowing. Natural infection of this plant species by group 16SrIX-A was reported previously in Colombia (Duduk et al, 2008), Brazil (Barbosa et al, 2012) and Puerto Rico (Caicedo et al, 2015).…”

“…Catharanthus roseus has been reported as a natural host for phytoplasmas groups 16SrI, 16SrIII, 16SrIX, 16SrXV, 16SrXIII, in North and South America, and the Caribbean islands, but not from the Central American region (Lee et al, 1998b;Lee, Davis, & Gundersen-Rindall, 2000;Montano, Dally, Davis, Pimentel, & Brioso, 2001b;Torres, Galdeano, Docampo, & Conci, 2004;Duduk, Mejia, Calari, & Bertaccini, 2008;Barbosa, Eckstein, Bergamin Filho, Bedendo, & Kitajima, 2012;Galdeano, Guzmán, Fernández, & Conci, 2013;Dumonceaux, Green, Hammond, Pérez, & Olivier, 2014;Caicedo, Rivera-Vargas, Segarra, & Davis, 2015;Davis, Harrison, Zhao, Wei, & Dally, 2016;Pérez-López, Luna-Rodríguez, Olivier, & Dumonceaux, 2016a). According to Montano et al (2001b), C. roseus is a well-known experimental host for phytoplasmas, however few incidences of natural infections have been reported and its role related to natural dissemination and disease spread is uncertain.…”

Adaptability and ‘CandidatusLiberibacter asiaticus’ titres of Diaphorina citri adults on three weed species in China

“…CLas occurs in some plants of non-Rutaceae, such as Catharanthus roseus L., Cuscuta campestris Yunker, 35,36 Lycopersicon esculentum Mill 37 and Nicotiana tabacum Xanthi, 38 and CLas bacteria were also detected in S. nigrum. 17 Thus, more studies are needed to determine whether these weed species favor the spread of CLas.…”

Identification of Nedotepa curta Dmitriev as a potential vector of the Côte d’Ivoire lethal yellowing phytoplasma in coconut palms sole or in mixed infection with a ‘Candidatus Phytoplasma asteris’-related strain

“…To date, the most documented phytoplasma vectors belonging to the Typhlocybinae are members of the tribe Empoascini (Galetto et al, 2011) enclosing Empoasca papayae, proven as vector of the phytoplasma associated with Bunchy Top Symptom of papaya (Acosta Perez et al, 2010). Other reports of typhlocybine vectors of phytoplasmas include E. decedens as a vector of European stone fruit yellows in Italy (Pastore et al, 2004) and potential vector in Lebanon for almond witches' broom (Abou-Jawdah et al, 2014); E. decipiens in Saudi Arabia for the lime decline disease (Alhudaib et al, 2009), alfalfa witches' broom (Al-Saleh et al, 2014), ranunculus virescence in Italy (Parrella et al, 2005) and almond witches' broom in Lebanon (Dakhil et al, 2011); and E. kraemeri for phytoplasmas infecting citrus species (C. sinensis and C. limon), coffee (Coffea arabica), periwinkle (Catharanthus roseus), and tabebuia (Tabebuia heterophylla) in Puerto Rico (Caicedo et al, 2015). Empoasca fabae and Erythroneura ziczac Walsh have been found as Fig.…”