Molecular detection and analysis of asian strain specific las fragment of huanglongbing bacterium (Candidatus Liberibacter asiaticus) vectored by Diaphorina citri Kuwayama (Hemiptera:Psyllidae) associated with decline of coorg mandarin (Citrus reticulata Blanco)

Coorg mandarins have been declining in a condition called as “greening”. Phloem limited Huanglongbing bacterium vectored by Diaphorina citri Kuwayama has been implicated as a major cause. PCR detection specific for asian strains using leaf mid vein tissues of Budlings adult psylla was done. The primer pair F-Las and R-Las amplified a 226 bp fragment specific for L. asiaticus (asian strain) both from infected plants and also from single infective Psylla. This fragment was analyzed and secondary structure of the proteins was predicted. The sequence is lacking dimmers or complex regions of similarity with 7 ORF's. The protein sequences FLAR_IF_4 had homology with RpoB putative 50S ribosomal subunit, Ribosomal protein L1 and UDP-3-0-3-hydroxymyristoyl glucosamine N-acyltransferase of Candidatus L. asiaticus and Candidatus L. africanus. The secondary structure was of alpha helices, extended strands, and random coils. The method is sensitive for detection and is time saving.