SEM studies on the Mediterranean olive root-knot nematode, Meloidogyne baetica, and histopathology on two additional natural hosts

SEM studies on a Meloidogyne baetica population provided additional details of the external morphology for female, male and second-stage juveniles. The labial disc in female and male specimens is fused with the medial lips forming a single structure. In second-stage juveniles the lateral lips are triangular with rounded margins. The amphidial opening for all life stages appears oval to rectangular in shape and is located between the labial disc and lateral lips. Lateral fields of male and second-stage juveniles have four incisures irregularly areolated along the entire body. The results of a host-range study for additional natural hosts of M. baetica conducted in wild olive communities growing at Vejer de la Frontera (Cadiz province) in southern Spain are also reported. Apart from the type host, M. baetica was found to infect two natural woody host plants, lentisc (Pistacia lentiscus) and Aristolochia baetica. Host parasite relationships in these new hosts confirmed the typical susceptible reaction observed in wild and cultivated olives. Similarly, the reproductive fitness, evaluated as the number of eggs per egg mass, was not significantly different in all plant hosts. No infections or galled roots were observed in herbaceous plant species studied and M. baetica must therefore be considered as a parasite of woody plants.