Journal of Pure and Applied MicrobiologyVol. 9 No. 3

Biological Control of Leaf Blight Disease in Gloriosa superba using Pseudomonas fluorescens

B. Meena* and K. Rajamani

Department of Medicinal and Aromatic Crops, Tamil Nadu Agricultural University, Coimbatore, India.

Received on 10 May 2015 and accepted on 02 July 2015

 

ABSTRACT

Leaf blight caused by Alternaria alternata is a destructive disease in Gloriosa superba. The effect of Pseudomonas fluorescens formulation in managing the leaf blight disease and in inducing resistance in gloriosa was investigated. P. fluorescens strain Pf1 significantly inhibited the growth of A. alternata in vitro. Dipping the tubers followed by foliar application of P. fluorescens at the rate of 2 g per litre on 30 and 60 days after planting was effective in managing the leaf blight disease and increasing the seed yield under field conditions. Changes in the activities of phenylalanine ammonia-lyase, chitinase, b-1,3-glucanase and in phenolic content of gloriosa leaves after application of P. fluorescens and inoculation with A. alternata were measured. There was a marked increase in the induction of defense compounds in response to pathogen inoculation in P. fluorescens treated gloriosa leaves.

Keywords : Leaf blight, Gloriosa superba, Pseudomonas fluorescens, defense compounds.