title: Genetic Diversity of the Indian Populations of 'Candidatus Liberibacter asiaticus' Based on the Tandem Repeat Variability in a Genomic Locus.
abstract: Citrus huanglongbing (HLB, citrus greening disease) is an extremely destructive disease affecting citrus and causes severe economic loss to the crop yield worldwide. The disease is caused by a phloem-limited, noncultured, gram-negative bacteria Candidatus Liberibacter spp., the widely present and most destructive species being 'Candidatus Liberibacter asiaticus'. Although the disease has been reported from almost all citrus growing regions of India, knowledge on the molecular variability of the pathogen 'Ca. L. asiaticus' populations from different geographical regions and cultivars is limited. In the present study, variability of the Indian 'Ca. L. asiaticus' based on the tandem repeats at the genomic locus CLIBASIA_01645 was characterized and categorized into four classes based on the tandem repeat number (TRN); Class I (TRN≤5), Class II (TRN>5≤10), Class III (TRN>10≤15), and Class IV (TRN>15). The study revealed that the Indian population of 'Ca. L. asiaticus' is more diverse than reported for Florida and Guangdong populations, which showed less diversity. While Florida and Guangdong populations were dominated by a TRN5 and TRN7 genotype, respectively, the Indian 'Ca. L. asiaticus' populations with TRN copy numbers 9, 10, 11, 12, and 13 were widely distributed throughout the country. Additionally, TRN2 and TRN17 genotypes were also observed among the Indian 'Ca. L. asiaticus' populations. The predominant 'Ca. L. asiaticus' genotypes from the northeastern region of India were TRN6 and TRN7 (53.12%) and surprisingly similar to neighboring South China populations. Preliminary results showed absence of preference of citrus cultivars to any specific 'Ca. L. asiaticus' genotype.
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Ghosh
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Sumit
authors.initials: S
authors.lastname: Bhose
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Manali
authors.initials: M
authors.lastname: Motghare
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Ashish
authors.initials: A
authors.lastname: Warghane
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Krishanu
authors.initials: K
authors.lastname: Mukherjee
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Dipak Kumar
authors.initials: DK
authors.lastname: Ghosh
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Ashwani Kumar
authors.initials: AK
authors.lastname: Sharma
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Milind Shivratan
authors.initials: MS
authors.lastname: Ladaniya
authors.affiliation: First, second, third, fourth, and eighth authors: National Research Centre for Citrus, PB 464, P.O. Shankarnagar, Nagpur 440010, India; fifth author: The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine 32080; sixth author: Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India; seventh author: Department of Biotechnology, Indian Institute of Technology, Roorkee 247 667, India; and ninth author: University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850.
authors.forename: Siddarame
authors.initials: S
authors.lastname: Gowda
mesh_terms: D001483:Base Sequence; D002957:Citrus / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D008969:Molecular Sequence Data; D052585:Phloem / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology*; D012230:Rhizobiaceae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D020080:Tandem Repeat Sequences / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial