2.5. Statistical analysis
The means and standard deviation of radial growth, submerged
growth and chitinase activity were calculated. Data
from soybean plant growth were statically analyzed by
using the analysis of variance (ANOVA) and DUNCAN
multiple range tests if a signiWcant diVerence was detected
(p< 0.05). SPSS, version 10.0 was used for statistical analysis.
3. Results and discussion
3.1. EVects of chitosan as a natural antifungal agent
on inhibition of the radial and submerged growth of
F. solani f. sp. glycines
There was no halo formation of F. solani f. sp. glycines
cultivated on 0 and 1 mg/ml of chitosan but the growth on 3
and 5 mg/ml chitosan-amended plates was restricted relative
to that of the control (Fig. 1) and the percentages of
radial growth inhibition were 38.2 and 54.6, respectively.
Furthermore, they also formed a halo around the colony on
the agar surface (data not shown). The halo-forming property
was used for testing the chitosanolytic activity in the
screening of Fusarium species, especially F. splendens and
F. solani. F. solani f. sp. phaseoli formed halo around the
colony on the 2.5 mg/ml of chitosan-containing agar plates
(Shimosaka et al., 1993)