Nine Fusarium species, isolated from cotton seedlings infected with
damping-off, were compared by double diffusion (DO) technique to determine
their serological relationships. On the basis of serological relationships,
species were grouped by cluser analysis and the results were expressed as
phenograms. Fusarium species were divided into two distinct groups. The
first group included F. subglutinans. F. moni/dorme. F. semitectum, and F.
so/ani, while the second group included F. semnucinum, F. oxysporum, F.
sporotricholdes, and F. pose. The use of common antigens or common
specific antigens gave the same taxonomic relationships. Regression
analysis was used to quantify the relationship between the no. of common
antigens (x) shared by Fusarium species and cotton cultivars and
pathogenicity (Y) of these species on these cultivars. Coefficient of
determination (R ) of the obtained models ranged from 0.81 to 0.90. These
results Indicate that 00 test constituted a positive test to quantify
pathogenicity of Fusarium species on cotton cutlivars.