Aly,, A., Hussein, E., Mansour, M., Tag El— Din, M. (2006). USE OF PEROXIDASE ISOZYMES T0 QUANTIFY VIRULENCE AND AGGRESSIVENESS 0F lSOLATES OF Fusarium oxysporum f.sp. vasinfectum PATHOGENIC 0N COTTON. Journal of Plant Production, 31(4), 2027-2039. doi: 10.21608/jpp.2007.235778
A. A. Aly,; E. M. Hussein; M. T. M. Mansour; M. A. Tag El— Din. "USE OF PEROXIDASE ISOZYMES T0 QUANTIFY VIRULENCE AND AGGRESSIVENESS 0F lSOLATES OF Fusarium oxysporum f.sp. vasinfectum PATHOGENIC 0N COTTON". Journal of Plant Production, 31, 4, 2006, 2027-2039. doi: 10.21608/jpp.2007.235778
Aly,, A., Hussein, E., Mansour, M., Tag El— Din, M. (2006). 'USE OF PEROXIDASE ISOZYMES T0 QUANTIFY VIRULENCE AND AGGRESSIVENESS 0F lSOLATES OF Fusarium oxysporum f.sp. vasinfectum PATHOGENIC 0N COTTON', Journal of Plant Production, 31(4), pp. 2027-2039. doi: 10.21608/jpp.2007.235778
Aly,, A., Hussein, E., Mansour, M., Tag El— Din, M. USE OF PEROXIDASE ISOZYMES T0 QUANTIFY VIRULENCE AND AGGRESSIVENESS 0F lSOLATES OF Fusarium oxysporum f.sp. vasinfectum PATHOGENIC 0N COTTON. Journal of Plant Production, 2006; 31(4): 2027-2039. doi: 10.21608/jpp.2007.235778
USE OF PEROXIDASE ISOZYMES T0 QUANTIFY VIRULENCE AND AGGRESSIVENESS 0F lSOLATES OF Fusarium oxysporum f.sp. vasinfectum PATHOGENIC 0N COTTON
1Plant Pathology Research Institute. Agric. Res. Center. Giza. Egypt.
2Dept. of Biochemistry,Faculty of Agric..Ain Shams Univ..Cairo. Egypt.
Abstract
Eight isolates of Fusarium oxysporum f.sp. vasinfeclum (FOV) were tested for
levels of pathogenicity on 45-day-old greenhouse grown seedlings of six cotton
genotypes. Isolates differed significantly (p=0.0000) in their pathogenicity on the
genotypes. Similarly, differences among genotypes were very highly significant
(p=0.0000) when they were tested against the isolates. isolate x genotype interaction
was a very highly significant (p=0.0094) source of variation in wilt incidence suggesting
that isolates responded differently to the different genotypes. These results imply that
the pathogenicity of the tested isolates is a mixture of both aggressiveness and
virulence and there are significant differences among isolates in both types of
pathogenicity. Similarly, resistance of the tested genotypes is also a mixture of both
horizontal and vertical resistance, and the genotypes significantly differ in both types of
resistance. Assessment of the relative contribution of each of these factors in the
explained (model) variation in wilt incidence revealed that isolate aggressiveness
accounted for 27.79% of the explained variation, horizontal resistance of the genotypes
accounted for 34.79%, and virulence of the isolates or vertical resistance of the
genotypes accounted for 35.12%. Peroxidase isozymes from mycelium and conidia of
the isolates were separated by polyacrylamide gel electrophoresis (PAGE). and the
obtained banding patterns were visualized by using a specific staining system. Data for
virulence or aggressiveness (dependant variables) and amounts of isozymes
(independent variables or predictors) were entered into a computerized stepwise
multiple regression analysis. Using the predictors supplied by stepwise regression, five
regression models were constructed to predict virulence of isolates on genotypes. Three
of the generated models proved effective in predicting isolate virulence on the
genotypes 417798, worse, and 545798. Coefficient of determination (R2) values of the
models were 98.19, 83.01, and 67.76%, respectively. it is noteworthy that the one-
variable model of aggressiveness showed the lowest R2 value (44.25%), which may
indicate that peroxidase isozymes are of limited value as biochemical markers to predict
aggressiveness of F0)! isolates. The results of the present study suggest that
peroxidase isozymes of isolates may provide a sUpplementary assay to greenhouse
tests to quantify virulence of FOV isolates.
View on SCiNiTO
Top