EVALUATION OF PRIMER SPECIFICITY USED FOR DETECTION AND FORMATION OF VIABLE BUT NON-CULTURABLE FORMS OF RALSTONIA SOLANACEARUMNeha Faridi, Shalini Bhatt, Merwyn P. Raj, Ankur Agarwal, Shraddha P. Mishra, Dinesh Pathak, Veena Pande, Mayank Pandey and Madhu Bala
Ralstoniasolanacearum is Gram-negative bacterial phyto-pathogens, which cause bacterial wilt disease inseveral vegetable crops of Solanaceaefamily. The bacterium is mainly soil and water borne in nature and spread through running water between different agricultural fields. In environment it can survive as VBNC (Viable But Not Culturable) state. Reverse Transcriptase qPCR (RT-qPCR) targeting housekeeping genes is a promising and reliable technique used to detect the VBNC forms of the pathogen. In present investigation three housekeeping genes namely, 16S rRNA, RpoS, and Omp, were evaluated for their specificity. Further to access the viability of the cells 16srDNA (16S rRNA) gene transcript was determined along with pathogenicity test. Strains of R. solanacearum DIBER-117 showed a 20% decrease in 16SrDNA gene transcriptome after 480 days. Among the three sets of primers tested, the primer targeting 16s rDNAis found to have better specificity.