SYEDA KOUSAR FATHIMA AND S. SHANKARA BHAT
Abstract
Phomopsis azadirachtae causes a destructive die-back of neem. Natural autofluorescence found in many mycelia and propagules was used by many workers for distinguishing non-viable spores from the viable ones. In the present investigations efforts were made to determine the viability of conidia of Phomopsis azadirachtae by the use of fluorescence microscope. Both alpha and beta conidia were screened for natural autofluorescence in their protoplasm. Alpha conidia showed about 15% and beta conidia showed 28% fluorescence in case of ungerminated conidial suspension. The germination was observed only in case of alpha conidia. There was no fluorescence in these germinated conidia. Thus use of fluorescence microscope was found to be a reliable, efficient, quick and simple method of determining viability of conidia in P. azadirach tae.