Isolation, Characterization and Screening of Fluorescent Pseudomonads against the Pathogens of Cymbidium Pseudobulb Rot

摘要

Fifty-four fluorescent pseudomonads were isolated from rhizosphere of potato and Cynbidium of different regions of Darjeeling Himalaya. Vast ranges of biochemical, morphological, cultural and physiological homology were evaluated. All the isolates were rod shaped, aerobic, gram' negative; as regard to their enzymatic activity they were oxidase positive, nitrate positive and arginine dihydrolase positive, they were levan positive and show negative result in Voges-Proskauer test. All the organisms were screened (in vitro) against Erwinia carolovora, Fusarium oxysporum and Mucor hiemalis f. hiemalis, the pathogens of Cymbidium pseudobulbs rot Among all the fluorescent pseudomonad native isolates, six (BRL-1, BRL-Dj-5, BRL-Sg-5, BRL-BB-9, BRL-Sg-1 and BRL-Sili-15) showed positive antagonism against all three pathogens.