Role of endophytic penicillium species in suppressing the root rotting fungi of sunflower

Micro-fungi have been the source of novel and pharmacologically active compounds over decades. Among them, genus Penicillium has been recognized as a rich source of bioactive metabolites. In this study, out of 80 plant samples, endophytic Penicillium species were isolated from 14 samples (root, stem and leaves) and identified as P. asperum, P. citrinum, P. duclauxi, P. javanicum, P. lividum, P. nigricans, P. decumbens, P. purpurogenum (3 isolates), P. lilacinum, P. restrictum, P. rugulosum and P. thomii. In dual culture plate assay all the fourteen isolates of Penicillium inhibited all four test fungi Fusarium oxysporum, F. solani, Rhizoctonia solani and Macrophomina phaseolina by producing zone of inhibition. Cell free culture filtrate also showed strong antifungal activity at higher dosages. Most of the isolates were significantly suppressed root rotting fungi and improved growth of sunflower in screen house experiments when applied alone or in soil amended with neem (Azadirachta indica A.Juss) cake. (author)