Diversity of nematophagous fungi in Moroccan olive nurseries: Highlighting prey-predator interactions and efficient strains against root-knot nematodes.

This study aims to isolate, identify and assess the diversity and the in vitro predatory activity of nematophagous fungi from various olive nurseries in Morocco. A total of 305 soil samples were collected in 25 nurseries in Moroccan olive-producing areas (Jbala, Guerouane, Haouz and Souss). Seventy-three pure fungal strains from nematophagous fungi were recovered from nursery substrates infested with root-knot nematodes. Diversity indices showed that fungi were more numerous in southern regions, whereas fungal communities were more numerically alike in northern regions, partly depending on the occurrence of root-knot nematodes. One fungal strain, Talaromyces assiutensis, killed all Meloidogyne javanica juveniles during in vitro predation tests. Orbiliaceae (Arthrobotrys spp., Drechslerella brochopaga, Monacrosporium spp.) trapped 50 to 80% of juveniles. Purpureocillium and Trichoderma species killed 30 to 50% of juveniles. The diversity of nematophagous communities could be affected by the north-south climate gradient of Morocco, by their nematode prey expansion, and, to a lesser extent, by the habitat origin of the substrates used. Talaromyces assiutensis was the most efficient nematophagous species against M. javanica. The use of native nematophagous fungi is a promising alternative strategy for nematode control in olive nurseries and to prevent nematode introduction into olive orchards.

Source: Biological Control - July 20, 2017 Category: Biology Source Type: research