“TOXICITY OF BACTERIAL PATHOGENS ISOLATED FROM ONION CROP GROWN IN ALWAR DISTRICT OF RAJASTHAN, INDIA”

Abstract

Toxins are chemical substances secreted by microorganisms which may affect host plants by causing a disease. Toxins have been identified in a wide range of phytopathogens. These have been classified as pathotoxins, vivotoxins and phytotoxins based on their mechanism of action and interaction with the host plants. Three replicates of twenty onion healthy seeds were treated with toxins of studied bacterial pathogens. These treated seeds were incubated to study the effects on seed germination, seedling health and seedling growth, and seedling vigour index (SVI). Toxin treated seeds showed less germination and seedling vigour index as compared to untreated seeds. Raised seedlings also showed symptoms of corresponding bacterial diseases. Seedling vigour index was recorded for toxin treated seeds 431.42 (Pseudomonas aeruginosa) and 587.61 (Pseudomonas syringae pv. syringae) as compared to 910 (healthy untreated).