Log concentration of Xcn1 was
used as abscissa and mycelial growth inhibition was used as
ordinate; linear regression equation was obtained for each
tested pathogenic fungal species (Table
2
). Results showed
a linear relationship between the log concentration of Xcn1
and mycelial growth inhibition. According to linear
regression, EC
50
values were calculated, with results rang-
ing from 0.25 to 4.17
l
g/L, displaying high antifungal
activity against five species of
Phytophthora
. However,
because
P. infestans
is a very important pathogen of tomato,
and potato late blight diseases causes serious economic
losses in China, it was selected for further research