Broad spectrum action of phenazine against active and dormant structures of fungal pathogens and root knot nematode

Antifungal antibiotic from Pseudomonas chlororaphis isolate PA23 was identified as Phenazine using TLC and HPLC. Phenazine recorded the highest inhibition zone of 21 mm with 35.55% percent inhibition of mycelial growth of Pythium aphanidermatum over control. It had a significant effect on the hyphal morphology of P. aphanidermatum and on spore germination of Botryodiplodia theobromae and Alternaria solani. Disorganization of hyphal morphology of P. aphanidermatum includes vacuolization, cell content degeneration and hyphal lysis. Similarly interaction of phenazine with Rhizoctonia solani resulted in abnormal swelling of hyphal tips was noticed in the hyphal tips. Similarly the germination of sclerotia of Macrophomina phaseolina, R. solani and Sclerotium rolfsii were completely inhibited by phenazine at a concentration 50 μl. Incubation of the eggs of the root knot nematode Meloidogyne incognita in 30 μl concentration of phenazine, completely suppressed the hatching of juveniles.