title: 'Candidatus Phytoplasma malaysianum', a novel taxon associated with virescence and phyllody of Madagascar periwinkle (Catharanthus roseus).
abstract: This study addressed the taxonomic position and group classification of a phytoplasma responsible for virescence and phyllody symptoms in naturally diseased Madagascar periwinkle plants in western Malaysia. Unique regions in the 16S rRNA gene from the Malaysian periwinkle virescence (MaPV) phytoplasma distinguished the phytoplasma from all previously described 'Candidatus Phytoplasma' species. Pairwise sequence similarity scores, calculated through alignment of full-length 16S rRNA gene sequences, revealed that the MaPV phytoplasma 16S rRNA gene shared 96.5 % or less sequence similarity with that of previously described 'Ca. Phytoplasma' species, justifying the recognition of the MaPV phytoplasma as a reference strain of a novel taxon, 'Candidatus Phytoplasma malaysianum'. The 16S rRNA gene F2nR2 fragment from the MaPV phytoplasma exhibited a distinct restriction fragment length polymorphism (RFLP) profile and the pattern similarity coefficient values were lower than 0.85 with representative phytoplasmas classified in any of the 31 previously delineated 16Sr groups; therefore, the MaPV phytoplasma was designated a member of a new 16Sr group, 16SrXXXII. Phytoplasmas affiliated with this novel taxon and the new group included diverse strains infecting periwinkle, coconut palm and oil palm in Malaysia. Three phytoplasmas were characterized as representatives of three distinct subgroups, 16SrXXXII-A, 16SrXXXII-B and 16SrXXXII-C, respectively.
authors.affiliation: Institute of Tropical Agriculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.
authors.forename: Naghmeh
authors.initials: N
authors.lastname: Nejat
authors.affiliation: Plant Protection Department, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.|Institute of Tropical Agriculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.
authors.forename: Ganesan
authors.initials: G
authors.lastname: Vadamalai
authors.affiliation: Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD 20705, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Davis
authors.affiliation: Department of Plant Pathology, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, FL 33314, USA.
authors.forename: Nigel A
authors.initials: NA
authors.lastname: Harrison
authors.affiliation: Plant Protection Department, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.
authors.forename: Kamaruzaman
authors.initials: K
authors.lastname: Sijam
authors.affiliation: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Dickinson
authors.affiliation: Agriculture Technology Department, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.|Institute of Tropical Agriculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Malaysia.
authors.forename: Siti Nor Akmar
authors.initials: SNA
authors.lastname: Abdullah
authors.affiliation: Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD 20705, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D030008:Catharanthus / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D008296:Malaysia; D008969:Molecular Sequence Data; D010802:Phylogeny; D045582:Phytoplasma / Q000145:classification* / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S