Recent advances in 16S rRNA gene-based phytoplasma differentiation, classification and taxonomy.

Molecular Characterization and Phylogeny of a Phytoplasma Associated with Phyllody Disease of toria (Brassica rapa L. subsp. dichotoma (Roxb.)) in India

“…Phytoplasmas have been classified according to 16S-rDNA phylogeny and RFLP profiles into 30 phylogenetic groups and 28 'Candidatus Phytoplasma' species [31]. The phytoplasma strains within a species should share at least 97.5% sequence identity within the 16S rRNA gene (Firrao et al 2005).…”

“…The phytoplasma strains within a species should share at least 97.5% sequence identity within the 16S rRNA gene (Firrao et al 2005). Subsequently in silico virtual RFLP analysis has been used as a powerful tool for groups and subgroups phytoplasma identification [15,[29][30][31]. However, because of its highly conserved nature, the 16S rRNA gene may not be adequate for finer differentiation of closely related but distinct phytoplasmas strains.…”

“…SecY, map and uvrB-degV genes were used to analyse strains in the 16SrV cluster [1]. As five subgroups in 16SrIX phytoplasma group have been identified [8,19,31], it was important to identify the phytoplasma subgroup associated with toria phyllody (TP) disease. Therefore, in silico virtual RFLP and phylogenetic analysis of 16S rRNA gene, actual RFLP of 16S rRNA and 23S rRNA genes, sequencing and phylogenetic analysis of ribosomal protein gene, 16S-23S rRNA intergenic spacer region, 23S rRNA and secA genes were attempted for characterization and phylogeny of a phytoplasma associated with TP disease using samples from four different locations in India.…”

Identification of a novel subgroup 16SrII-U phytoplasma associated with papaya little leaf disease

“…The peanut witches' broom phytoplasma group (16SrII) exhibits high genetic diversity (Cai et al, 2008;P erez-López et al, 2016;Zhao et al, 2010). At the time of writing, 20 16S rRNA gene subgroups had been recognized in the peanut witches' broom phytoplasma group.…”

‘Candidatus Phytoplasma hispanicum’, a novel taxon associated with Mexican periwinkle virescence disease of Catharanthus roseus

“…Importantly, newly discovered plant diseases and diseases of previously unknown cause are increasingly being attributed to phytoplasmas (Zhao et al, 2014). The phytoplasmas have been classified into a series of groups and subgroups on the basis of RFLP patterns of 16S rRNA gene sequences (16S rDNA) (Lee et al, 1998;Wei et al, 2007;Zhao et al, 2010), and 38 'Candidatus Phytoplasma' species have been described and named on the basis of nucleotide sequence differences in 16S rDNA (Table 1) (Harrison et al, 2014;Šafarova et al, 2016;IRPCM, 2004). Additional phytoplasmas that warrant recognition as distinct 'Candidatus Phytoplasma' taxa have remained undescribed as such (Wei et al, 2007); one of these phytoplasmas is the Mexican periwinkle virescence (MPV) phytoplasma.…”