Occurrence of spiroplasma and phytoplasma in sesame affected with yellowing disease in India

Sesame plants (Sesamum indicum) showing from severe yellowing disease were observed during the period of July to September 2010 in North Delhi, India. To investigate the associated pathogen genomic DNA was used in PCR assays with primers specific for spiroplasma abc protein b-subunit (designed in the current study) and for 16S rDNA of phytoplasma. Affected plants tested positive for both spiroplasma and phytoplasma in 84% cases by showing the presence of ~0.5kb and ~1.25kb amplicon, respectively. Sequence analysis showed 99% matches with Spiroplasma citri and ‘Candidatus Phytoplasma asteris’ members. Phylogenetic reconstruction performed using MEGA version 4.1 confirmed the above classification. So far, this is the first report of coexistence of these two mollicutes in sesame from the Asiatic region.