Five biochemical descriptors were assessed in cotton plants infected with the ramulosis-causing fungus in order to detect differences associated with the infection. Seeds from four cotton cultivars with different levels of resistance were sown in plastic containers in greenhouse conditions. At 20 days after emergence, plants were inoculated with a suspension at 1 x 10(6) conidia/mL of Colletotrichum gossypii var. cephalosporioides. Leaves were collected at 3, 15 and 30 days after inoculation and free proline, catalase, peroxidase, soluble carbohydrates and total proteins were determined. Proline, peroxidase and catalase levels discriminated the reaction of infected plants. These descriptors changed soon after infection and the change was more evident in the resistant BRS Antares variety. Free proline and catalase descriptors can be used in the identification of ramulosis-resistant cultivars in cotton breeding programs.
Cotton disease; enzyme; metabolites; ramulosis
