Variability of Parasitic Specificity in Curvularia Spicifera

An isolate of Curvularia spicifera obtained from Opuntia ficus indica growing around a citrus orchard, was capable to induce different symptoms in plants of Citrus aurantium, the most widely used citrus rootstock in Morocco. Dipping inoculation method of roots Citrus aurantium plants into spore suspension (106 spores/mL) of Curvularia spicifera isolate had resulted in unexpected disease symptoms development. Among these, root necrosis accompanied with moderate to general stunting of root system and aerial plant parts. In terms of plant growth parameters, the length of the root and aerial parts were reduced to 6.1 and 6.8 cm in inoculated plants relative to 9 and 12.1 in control plants. The infection was established through the roots which failed to branch normally displaying less density of secondary and tertiary roots with 8/23 compared to 18 /42 in the controls. The fungus was reisolated from the roots of the inoculated plants. This study revealed the parasitic potential acquired by C. spicifera towards a no specific hosts like Citrus aurantium in the case of longtime cohabitation. The parasitic specificity of Curvularia spicifera was discussed in this study.