Isolation, Identification and Characterisation of Fungal Endophytes from Plectranthus amboinicus L.

Fungal endophytes of Plectranthus amboinicus L. were explored for their antifungal activity against phytopathogen Sclerotinia sclerotiorum and plant-growth-enhancing traits. Fungal isolates were genotyped using the ITS-rDNA regions. Chaetomium subglobosum exhibited the highest mycelial growth inhibition of 80% against phytopathogen Sclerotinia sclerotiorum in dual-culture bioassay carried out in czapek dox medium. Of the various plant-growth-enhancing traits evaluated in endophytic isolates, C. subglobosum was found to be positive for HCN, IAA, siderophore and ammonia production. None of the endophytic isolates were able to solubilise phosphate in in vitro conditions. IAA was produced by C. subglobosum , Alternaria alternata and Fusarium oxysporum as characterised qualitatively by RP-HPLC. Highest quantity of IAA (97 ng/ml) was secreted by Fusarium oxysporum as detected through spectrophotometric analysis at 530 nm.