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Huanglongbing (HLB, Citrus greening), caused by a phloem-limited fastidious gram-negative bacterium, “Candidatus Liberibacter spp.”, is one of the devastating diseases of citrus worldwide. The pathogen belongs to the alpha-proteobacteria group and is classified on the basis of its geographical origin and 16S rRNA sequence diversity. Although the disease has been reported from all citrus growing states of India, the status and the molecular variability among the isolates from the Northern part of the country is unknown. A total of five different HLB isolates originating from Northern India showing variable symptoms were studied. The genomic regions of four different genes, i.e., 16S rRNA, intergenic 16S/23S rRNA spacer region, rplA-rplJ, and CLIBASIA_01645 were amplified by PCR, sequenced, and variations in these sequences were assessed. Analysis of 16S rRNA clearly indicated that all five isolates fit in to …