This study described the development of stalk-rot caused by Fusarium verticillioides on plantain fruits and the route of infection. Stalk and the crown tissues of mature green plantain fruits on parent plants were inoculated with a suspension of F. verticillioides containing 5.341x106 conidia ml-1, left for 15 days before harvesting and storage at 28° ± 2°C and 98% relative humidity. Control was not inoculated. Another set of fruits of same maturity were harvested before inoculation and storage. Sections of inoculated and uninoculated pedicel and crown tissues were prepared into permanent slides, stained and observed under the microscope. Crude enzyme was obtained from plantain peel-water (10% w/v) broth inoculated with the same conidia suspension containing 5.341x106 conidia ml-1. Partial purification of the crude enzyme was carried out with ammonium sulphate then pectin methyl esterase, polygalacturonase, pectin lyase, and cellulose were assayed. Results showed sub-cuticular hyphae and conidia of F. verticillioides in the stalk and crown tissues of inoculated and uninoculated plantain fruits. Sections of fruits harvested before inoculation and storage became disrupted between 20th and 25th days of storage. The fungus produced pectin methyl esterase, polygalacturonase, pectin lyase and cellulase in vitro and in vivo. The infection was asymptomatic on parent plants but became necrotic on harvested fruits during storage. These observations showed that stalk-rot induced by F. verticillioides on plantain fruits is latent, it occurred by systemic infection from the field. It also occurred as a result of contamination of harvested fruits, since fruits inoculated after harvest became diseased at points of inoculation during storage. Keywords: Stalk-Rot, Fusarium verticillioides, Plantain, Enzyme.
PAPER TITLE :ACTIVITIES OF FUSARIUM VERTICILLIOIDES DURING THE DEVELOPMENT OF STALK-ROT IN PLANTAIN FRUITS
FUTA JOURNAL OF RESEARCH IN SCIENCE | VOLUME 11 NUMBER 2 2015
- Author(s) : O. M. Akomolafe, A. T. Aborisade and R. E. Okonji