Abstract

Verticillium dahliae Klebhan, is a soil- borne vascular pathogen, found in temperate regions all over the world. Salicylic acid (SA) treated and untreated seedlings of brinjal were histologically investigated for their infection and defense response to wilt causing and defoliating strain of Verticillium dahliue Kleb. SA plays an important role in signaling and the activation of various plant defense responses to pathogen attack. SA has been used to control the disease (Veticillium wilt) with the different concentrations viz, 0.25, 0.5, 0.75 and 1.0 mM. Histopathological studies have been conducted at different time gap studies (viz , 0, 3, 6, 12, 24, 48, 72 and 96 hours), whereas the SA primed seedlings acquired resistance by forming Papillae, Hypersensitive Reaction (HR), cell wall thickening etc. In the susceptible seedlings, V. dahliae colonizes via the primary roots, the infection process increased at 24 hr after inoculation and ramification increases at 72 hr which finally leads to death. However the infection process showed significant difference between susceptible and SA treated seedlings of eggplant. The V. dahliae showed slow infection process in SA treated brinjal seedlings along with defense structures.

Key words: Egg Plant, Salicylic acid, Hypersensitive Reaction (HR), Papillae, Verticillium Wilt, Host-Pathogen interaction.