First report on molecular detection of a stolbur phytoplasma (Group16SrXII-A) associated with kenaf ( Hibiscus cannabinus L.) in India.

Infection of stolbur phytoplasma was detected in kenaf (Hibiscus cannabinus) plants at CRIJAF research farm, Barrackpore, India. The infected plants formed profuse short branches at the top with bushy and bunchy top appearance. PCR with universal 16S rDNA phytoplasma primers P1/P7 yielded amplicons of 1.5 kb from all symptomatic leaf samples. Nested PCR with 16S-rDNA-specific nested primer pair R16F2n/R2 generated an amplicon of 1241 bp confirming the presence of a phytoplasma. The nested PCR products were sequenced and BALSTn analysis revealed 100% identity with 16S rRNA gene of phytoplasma. Phylogenetic analysis showed kenaf phytoplasma having 99% identity with both “Bois noir” stolbur phytoplasma 16SrXII group (Accession no: JQ181540). The RFLP data also supported the phylogenetic analysis. Multi-locus sequence characterisation assay was conducted by using different locus-specific primers viz. tuf, rpsC-rplV, rplF-rplR, map-SecY and uvrB-degV. The infected phytoplasma samples amplified only SecY gene and generated 1224 bp product which was deposited at NCBI (accession no: KC508636). [ABSTRACT FROM AUTHOR]