Isolation and Characterization of Fusarium moniliforme var. subglutinans from Malformed Mango

Abstract

Mango malformation occurs in most mango growing regions of the world. Floral and vegetative malformation have been reported. There is general agreement that the fungal pathogen Fusarium moniliforme var. subglutinans or Fusarium subglutinans is the causal agent. Healthy and malformed samples of both floral and vegetative tissues were collected from different varieties of mango grown in several locations to verify the association of F.moniliforme with mango malformation disease in Pakistan. The fungus was isolated and cultured. Frequency of fungal association with the disease ranged between 90- 94%, There was less recovery of fungus from asymptomatic tissue (12- 15%). There was no difference among the commercial mango varieties in the level of susceptibility to this disease. However, seedling germplasm and land races showing resistance to mango malformation were identified. The in vitro growth characters of the fungus were determined on different culture media, at varying temperatures, light and pH conditions. Mycelial growth on potato dextrose agar was better than nine other media tested. At pH 7.00, the ideal temperature for growth was between 25-30° C. Normally, the malformation is not controlled by fungicide application. The in vitro sensitivity of fungus to six fungicides at three concentrations was determined to seek potential means of chemical control.