Pathological and physiological studies on macrophomina phaseolina the causal organism of bean charcoal rot disease [electronic resource].

Includes references.

Pathogenicity tests of Macrophomina phaseolina (Tassi) Goid. (pycnidial stage of Sclerotium bataticola Taub.) isolates proved that, all they were pathogenic to Xera bean cultivar. The isolate, which isolated from sweet melon roots was the most pathogenic one, followed by that isolated from bean roots and then that isolated from sesame stem. In vitro studies revealed that the most suitable degrees of temperature for the linear growth of the tested isolates ranged between 2S-35°C. On the other hand, at 15°C, the linear growth was low and differed with the different isolates. Three infested barley seeds Ibean seed as inoculum was enough to incidence the disease. Sesame was the most susceptible host followed by wheat and maize, which were moderate.. however cantaloupe was the lowest susceptible host. Fungal culture filtrates at different concentrations reduced the percentage of seed gennination and had hannful effect on rootlet length and dry weight. Enzymatic activity of the fungus (pectin methyl esterase, polygalacturonase and cel1ulase) was ,assessed in the culture filtrate andlor extract of infected bean plants.

Summary in Arabic.

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