Comparative study of Colletotrichum gloeosporioides isolates as to effect of carbohydrate nutrition on the growth, sporulation and pathogenicity on fruits from three mango varieties.
Assis T. C. de, Menezes M., Andrade D. E. G. T., Coelho R. S. B., Oliveira S. M. A.
Author Affiliation: UFRPE, Departamento de Agronomia, Área de Fitossanidade, CEP 52.171-900, Recife, PE, Brazil.
Summa Phytopathologica 27 : 208-212
Abstract : Isolates of C. gloeosporioides [Glomerella cingulata] (ISO-1, ISO-2, ISO-3, ISO-4, ISO-5 and ISO-6) were studied in relation to the effect of different carbohydrate sources (glucose, maltose and starch) on the mycelial growth, sporulation and dry weight of the pathogen, as well as the pathogenicity on fruits of three mango cultivars (Espada, Rosa and Tommy). For the physiological characterization of isolates, the basal culture medium, potato agar, was added with the different carbohydrate sources. For pathogenicity, the isolates were either cultivated in the same carbohydrate sources or inoculated on mango fruits. The culture medium added with starch provided the largest mycelial growth, sporulation and dry weight for most of the studied isolates. In the pathogenicity analysis, all of the isolates induced necrotic lesions on the fruits used in the tests, but the symptoms varied according to isolate and substrate used. Starch was the best inducer of pathogenicity of C. gloeosporioides. Among the cultivars, Rosa was the most susceptible to C. gloeosporioides. The isolate ISO-4 presented the largest capacity to induce symptoms in the mango fruits and the media with starch offered the best conditions for the growth and reproduction of this pathogen.