Selective medium for isolating Nattrassia mangiferae.
Saaiman W. C., Smith Z.
Author Affiliation: Merensky Technological Services, PO Box 14, Duivelskloof 0853, South Africa.
: 587-594
Abstract : N. mangiferae is the causal agent of various mango diseases in South Africa. These include blossom blight and the postharvest diseases soft brown rot and stem end rot. The isolation of N. mangiferae from mango tissues by plating onto agar media can be hampered by the presence of saprophytic fungi. Therefore, a selective medium was developed to avoid this. Ten chemicals were screened for their effect on the radial growth of N. mangiferae. N. mangiferae growth was least affected by benodanil (100 ppm) followed by rose bengal (50 ppm) and tannic acid (3000 ppm). These 3 chemicals were then tested at different concentrations and combinations for their effect on the radial growth of N. mangiferae and 7 other fungi commonly isolated from mango tissues. A selective medium consisting of tannic acid (4000 ppm) and benodanil (100 ppm) was best for the detection of N. mangiferae in isolations made from mango branches, flowers and fruits.