title: Population genetic analysis reveals a low level of genetic diversity of 'CandidatusPhytoplasma aurantifolia' causing witches' broom disease in lime.
abstract: Witches' broom disease of lime (WBDL) is a serious phytoplasma disease of acid lime in Oman, the UAE and Iran. Despite efforts to study it, no systemic study attempted to characterize the relationship among the associated phytoplasma, 'CandidatusPhytoplasma aurantifolia', from the three countries. This study utilized sequences of the 16S rRNA,impandsecAgenes to characterize 57 strains collected from Oman (38), the UAE (9) and Iran (10). Phylogenetic analysis based on the 16S rRNA gene showed that the 57 strains shared 98.5-100 % nucleotide similarity to each other and to strains of 'Ca. P. aurantifolia' available in GenBank. The level of genetic diversity was low based on the 16S rRNA (0-0.011),imp(0-0.002) andsecAgenes (0-0.015). The presence of low level of diversity among phytoplasma strains from Oman, the UAE and Iran can be explained by the movement of infected lime seedlings from one country to another through trading and exchange of infected plants. The study discusses implication of the findings on WBDL spread and management.
authors.affiliation: Royal Court Affairs, Seeb, Oman.
authors.forename: Shaikha Y
authors.initials: SY
authors.lastname: Al-Abadi
authors.affiliation: Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, PO Box 8, 123 Al Khoudh, Oman.
authors.forename: Abdullah M
authors.identifier: 0000-0002-3419-8268
authors.initials: AM
authors.lastname: Al-Sadi
authors.affiliation: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Dickinson
authors.affiliation: Abu Dhabi Food Control Authority, PO Box 52150, Abu Dhabi, UAE.
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Al-Hammadi
authors.affiliation: Abu Dhabi Food Control Authority, PO Box 52150, Abu Dhabi, UAE.
authors.forename: Rashid
authors.initials: R
authors.lastname: Al-Shariqi
authors.affiliation: Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, PO Box 8, 123 Al Khoudh, Oman.
authors.forename: Rashid A
authors.initials: RA
authors.lastname: Al-Yahyai
authors.affiliation: Islamic Azad University, Shiraz, Iran.
authors.forename: Elham A
authors.initials: EA
authors.lastname: Kazerooni
authors.affiliation: Department of Agricultural Sciences, Plant Pathology, Alma Mater Studiorum-University of Bologna, Bologna, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Bertaccini
keywords: Acid lime; Phytoplasma; Population structure; WBDL