Molecular Detection and Management of Tomato Leaf Curl Virus with Pseudomonas fluorescens and Chitosan

Tomato production is affected by various fungal, bacterial and viral diseases that attribute to considerable yield losses. Among all the diseases of tomato, Tomato Leaf Curl Virus (ToLCV) disease is cited to be the most devastating both in terms of quantitative and qualitative yield losses. Often, the loss reaches to the extent of 100% during summer throughout India. The virus associated with tomato leaf curl disease was detected by PCR using coat protein specific primers. The present investigations were carried out with potent Pseudomonas fluorescens isolates alone and along with elicitor molecule chitosan to determine its ability to control ToLCV in tomato. Different formulations of P. fluorescens and chitosan were evaluated for controlling ToLCV and growth promotion of tomato. It was found that the application of P. fluorescens isolates Pf1 and Pf2 @ 5kg/ha in combination with chitosan @ 5% reduces the severity of the ToLCV disease by 80 – 90 %. Application of chitosan and P. fluorescens alone caused 60 – 70% reduction in severity of ToLCV disease. Moreover, the plants inoculated with the chitosan based formulation of P. fluorescens isolates Pf1 and Pf2 recorded maximum plant height, fruit number and yield/plant over the control in potted condition. The results, thus, indicate that addition of chitosan has enhanced the biocontrol efficacy of P. fluorescens against ToLCV.