2.3. Measurements of spore germination and germ tube elongation
The effects of chitosan and oligochitosan on spore germination
and germ tube elongation of A. kikuchiana and P. piricola were assayed
according to Liu et al. (2007). Fifty microlitre aliquots of both
conidial suspensions at 1 106 spores mL1 were plated evenly on
Petri dishes (60 mmin diameter) with 10 ml solid PDA or PSA medium,
which contained different concentrations (0, 0. 1, 0. 3, 0. 5,
0. 7, 1.0, 2.0 and 5.0 g/L) of chitosan and oligochitosan, and the Petri
dishes incubated at 25 C for 6 h. More than 200 spores of each
pathogen were measured for germination spore and germ tube
length per treatment within each replicate. Then the inhibitory
rate of spore germination and germ tube length and their IC50
was determined. Each treatment contained three replicates and
the experiment was repeated twice.