EFFECT OF DIFFERENT DISCS OF HOSTS’ LEAVES ON THE SPORULATION

Resumo

This work aimed to study the effect of leaf discs of cowpea plant [Vigna unguiculata (L. Walp.], wheat plant (Triticum aestivum L.), and corn plant (Zea mays L.) on the sporulation of the fungi Macrophomina phaseolina (Tassi) Goid. The trials were assembled in a 2 x 5 factorial arrangement (temperature x sporulation substrate), with four replicates. The experimental plot was a Petri dish with PDA growth medium over which six leaf discs from the species mentioned (Ø 0.7 cm) were laid. The incubation temperature was 25°C and 30°C under a continuous light regime. A disc made of filter paper and PDA growth medium was used as a control. A 0.4-cm-diameter PDA disc colonized with fungal mycelium was placed at the central part of each Petri dish. The evaluation was performed at the 9th day of incubation by estimating the number of conidia.mL-1.disc-1.Petri dish-1. The data were tested by ANOVA, followed by a multiple comparation test of averages (Tukey Test) a 0.01. The best sporulation was obtained from the discs contained wheat incubated at 25°C (42.6 x 103 conidia.mL-1.disc-1.Petri dish-1), followed by the same substrate at 30°C (39.1 x 103 conidia.mL-1.disc-1. Petri dish-1).