Modified Spore Germination Inhibition Technique for Evaluation of Candidate Fungitoxicant (Eucalyptus spp.)

Abstract

The technique of spore germination inhibition has been modified by introducing the mathematical model for standardization of inoculum, reducing the cost as well as observation period thereby making the technique simple and no chance of contamination for the evaluation of candidate fungitoxicant(s). The present technique is compared with prevalent poisoned food technique and we found that quantitative results are almost the same. Amongst the candidate essential oils extracted from Eucalyptus citriodora, E. dalrympleana, E. laveopinea, E. pauciflora, only the oil off. citriodora at 1000 mg/ml showed complete inhibition of spore germination of the storage spoilage test fungus Penicillium italicum. The oil of E. dalrympleana and E. laveopinea showed fungistatic toxicity against the test fungus at 3000 mg/ml but the oil of E. laveopinea showed partial inhibition at 3000 mg/ml. The oil of E. citriodora at 1000 mg/ml exhibited fungicidal nature and withstood heavy inoculum. Since the oil at sublethal concentration exhibited no abnormalities at morphological level, the total picture can be drawn only after undertaking the work on cytological and at enzymatic level against the test fungus.