Journal of Pure and Applied MicrobiologyVol. 8 No. 6

Subcellular Changes in Tomato Leaves during Induced Resistance Elicited by Rhizobacteria and Chitosan against Tomato Leaf Curl Virus (ToLCV) under Field Conditions

Shefali Mishra1*, K.S. Jagadeesh1 and P.U. Krishnaraj2

1Department of Agricultural Microbiology, 2Department of Biotechnology. College of Agriculture, Dharwad, University of Agricultural Sciences, Dharwad - 580 005, India.

Received on 15 July 2014 and accepted on 10 September 2014

 

ABSTRACT

High field incidence of diseases caused by insect transmitted viruses pose serious epidemic of ToLCV on tomoato, where the insecticides completely ineffective to preventing in the spreading the virus. Application of rhizobacterial mixture in combination with chitosan reduced the severity of ToLCV (Tomato leaf curl virus) diseased plants by 83.6?93.3 per cent. The plants inoculated with the chitosan based formulation of Pseudomonas sp.(206(4) +B-15+ JK-16) showed concomitant increase in plant height, total biomass, chlorophyll content, fruit yield and shelf life over the diseased control. The quantification of the virus, as done through semi quantitative PCR analysis, revealed the least viral load accumulation in plants inoculated with both chitosan and rhizobacterial mixture. The subcellular changes inside the cells, as studied by transmission electron microscopy revealed moon shaped chloroplasts and complete loss of subcellular architecture within the diseased cells. While, in rhizobacterial mixture + chitosan treated leaves, the cells appeared somewhat closer to normal cells, with a small extent of distortion in chloroplasts. Our results imply that the rhizobacterial mixture + chitosan as the most efficient and alternative strategy for the management of insect transmitted ToLCV disease severity in tomato, besides promoting plant growth and fruit yield.

Keywords : Pseudomonas spp., ToLCV, chitosan, biocontrol, Bemisia tabaci, transmission electron microscopy.