Biochemical and Morphological Characterization of Pseudomonas fluorescens Isolates and its in vitro Efficacy Against Damping off in Chilli

This study examines that three isolates of Pseudomonas fluorescens (PDKV Pf1, Pf2, Pf3) isolated from the chilli rhizosphere, focusing on their ability to produce hydrogen cyanide (HCN) and indole production (IAA) as a plant growth-promoting compound. All isolates were identified morphologically as gram-negative and rodshaped, with PKDV Pf1 displaying strongly positive results in several biochemical tests such as catalase, oxidase, triple sugar iron (TSI), arginine dehydrolase, starch hydrolysis, H2S production, methyl red test, citrate utilization, HCN production and gelatin liquefaction. Notably, PKDV Pf1 exhibited the highest growth inhibition of 57.11% againstPythium aphanidermatum, surpassing PKDV Pf2 (53.75%) and PKDV Pf3 (44.68%). These characteristics indicate that Pf1 has potential as an effective biocontrol agent. These results showed that biochemical and morphological attributes of Pf1 underscore its significance in supporting sustainable agricultural practices and improving crop health. Its environmentally friendly profile presents a viable alternative to synthetic fungicides, thereby reducing ecological harm.