Strains of Rhizoctonia solani resistant to chlorinated nitrobenzenes
| MSI99P0010 | |
| Ricaud, C. | |
| University of London, Imperial College of Science and Technology, London, GB | |
| Strains of Rhizoctonia solani resistant to chlorinated nitrobenzenes | |
| Thesis, Ph.D., Botany: Plant Pathology | |
| Thesis | |
| 1965 | |
| 82 p.: 22 tbls., 2 graphs, 7 pl. | |
| En | |
| En | |
| The effect of pentachloronitrobenzene (PCNB) and tetrachloronitrobenzene (TCNB) on three strains of Rhizoctonia solani was studied. These strains were differently affected by the two fungicides on agar. R. solani lettuce strain was the most susceptible to both fungicides, the effect on Corticium practicola was intermediate and R. solani swede strain was the least affected. PCNB was more effective than TCNB in inhibiting growth. These results were not strictly correlated with the effects of the fungicides in controlling damping-off caused by these strains. In the case of R. solani (S), TCNB gave better control than PCNB in soil. The three strains differed also in their ability to develop tolerance to these fungicides. No sign of adaptation was observed with R. solani (S) and with C. practicola only a few resistant variants were noticed. Cultures of R. solani (L) produced resistant variants abundantly in presence of PCNB. Some of these resistant strains differed appreciably from each other morphologically, in their degree of resistance and in their ability to infect lettuce. In two of these strains resistance was associated with a certain dependence on the fungicide. Resistance was not lost when these strains were subcultured for several generations in absence of the fungicides. Three of the resistant strains studied were slightly less pathogenic to lettuce than the parent strain. The two strains which had become fungicide-dependent were not pathogenic. However, it appeared that the resistant strains could still be controlled by the fungicides in soil. Development of resistance was not detected when soil inoculated with the original strains was treated with the fungicides. Nuclei in the mycelium of the three original strains growing in presence of the fungicides were found to be larger than in corresponding untreated mycelium. | |
| FUNGUS RHIZOCTONIA FUNGICIDES THANATEPHORUS CUCUMERIS QUINTOZENE PATHOGENS diseases | |
| MAURITIUS | |
| Plant diseases | |
| Rhizoctonia solani | |
| 1991-10-03 | |
| En | |
| Mauritius Sugar Industry Research Institute | |
| LIB | |
| CAT | |
| 1 | |
| PATH |