microscopy. live hyphae were examined by light microscopy as described previously. for fluorescence microscopy, the samples were prepared as described above and the hyphae were mounted in 50% glycerol before observation. for staining hyphae or DNA,samples of cells were fixed three times whit methanol and then washed with water and covered with poyl-L-lysine solution. the cells were stained with propidium iodide (PI) or calcofluor work solution for about 10 or 5 min,respectively,and then washed with water and mounted with 50% glycerol before observation under the Olympus BX51 fluorescence.