Biochemical characterization of Fusarium oxysporum f. sp. cubense isolates from India

The Fusarium wilt caused by Fusarium oxyspoum f. sp. cubense (Foc) is a major biotic constraint for banana production. The characteristics of F. oxyspoum f. sp. cubense isolates were investigated using electrophoretic studies of isozyme and whole-cell protein. The morphological characteristics of the isolates were very similar to each other. All the Foc isolates were pathogenic to banana cultivar 'Nanjangud Rasabale' but they did not induce any disease symptoms on cultivar 'Cavendish'. F. oxyspoum (Isolate 6) did not induce wilt symptoms on either 'Nanjangud' or 'Cavendish' cultivar. Isozyme banding patterns showed 46 scoreable markers and cluster analysis with UPGMA using genetic distance showed that the isolates belonged to three main groups. Group 1 contained isolates 1, 2, 4, 5, 7 and isolate 3 and 6 were placed in group 2 and 3. Results indicated that the estimated intra-specific variation may be more pronounced with isozyme analysis than with protein markers. The level of isozyme variability detected within F. oxysporum f.sp. cubense suggested that it is reliable, efficient and effective in determining genetic relationships among Foc isolates

Biochemical characterization of Fusarium oxysporum f. sp cubense isolates from India

The Fusarium wilt caused by Fusarium oxyspoum f. sp. cubense (Foc) is a major biotic constraint for banana production. The characteristics of F. oxyspoum f. sp. cubense isolates were investigated using electrophoretic studies of isozyme and whole-cell protein. The morphological characteristics of the isolates were very similar to each other. All the Foc isolates were pathogenic to banana cultivar 'Nanjangud Rasabale' but they did not induce any disease symptoms on cultivar 'Cavendish'. F. oxyspoum (Isolate 6) did not induce wilt symptoms on either 'Nanjangud' or 'Cavendish' cultivar. Isozyme banding patterns showed 46 scoreable markers and cluster analysis with UPGMA using genetic distance showed that the isolates belonged to three main groups. Group 1 contained isolates 1, 2, 4, 5, 7 and isolate 3 and 6 were placed in group 2 and 3. Results indicated that the estimated intra-specific variation may be more pronounced with isozyme analysis than with protein markers. The level of isozyme variability detected within F. oxysporum f. sp. cubense suggested that it is reliable, efficient and effective in determining genetic relationships among Foc isolates

Effect of plant extracts and ascetone precipitated proteins from six medicinal plants against tobamovirus infection

The present study was taken up to evaluate the effect of leaf extracts and acetone-precipitated protein of medicinal plants on seed-borne Tobacco Mosaic Virus (TMV) and Tomato Mosaic Virus (ToMV) infection. The antiviral activity was tested on indicator plant Nicotiana glutinosa. Acetone precipitated proteins and solvent extracts of six medicinal plants were tested for their effect on tobamovirus infection. The aqueous leaf extracts of Guava, Phyllanthus and Thuja were effective in reducing the infection by ToMV. The acetone-precipitated fractions of Tridax, Thuja, Guava and Tulsi were effective in reducing the infection by TMV. The solvent extract of Guava was effective in reducing the ToMV infection. Guava extract was subjected to TLC and the fractions were tested for their antiviral activity. Fraction with RF value of 0.014 proved to be effective in reducing the ToMV infection. The solvent extract of Thuja was effective in reducing TMV infection. TLC fraction of Thuja extract with the RF value of 0.12 reduced the TMV infection. Along with this, effect of aqueous leaf extracts on seed quality parameters of tomato and bell pepper was studied