Potential of Millet Grains as Alternative Media for Preservation of Fungal Pathogen

Abstract

Crop losses due to pathogen attacks had increased tremendously from year to year and this situation is very alarming. Among important pathogen, fungi are dominant causal agents of plant disease that manage to colonize the host with various strategies and finally kill them. Identification based on laboratory investigations become vital since there are many kinds of fungi linked to plant disease. Laboratory investigations might take a long period thus effective storage and preservation of fungal cultures are critical to ensuring their viability and maintaining their genetic integrity. Conventional agar medium preservation is not really ideal for long-term study since it requires repetitive sub-culturing, which can change the pathogen’s characteristics and contaminate the fungal cultures. This study has determined the potential of millet grains as alternative media for preservation of fungal pathogen using three different drying process. Two species of fungi that related with dieback disease of woody plants such as Parkinsonia, mango, cocoa and apple have been used in this study namely Lasiodiplodia pseudotheobromae and Neoscytalidium novaehollandiae. The effectiveness of the millet grains as culture media were assessed based on viability and contamination rates. Millet grains that have been cultured with the fungal pathogen were dried using three drying process which are air drying, oven drying and freeze drying. Viability test revealed that both fungi produced high viability rates even after 8 weeks of storage period in the millet grains. The least contamination rate recorded by millet grains that have been dried using oven drying. The findings indicate that millet grains habe a great potential as an alternative media for preservation of fungal pathogen.