Evaluation of Methods for Extraction of Nematodes and Endoparasitic Fungi From Soil

Abstract

Six methods were tested for nematode extraction: the Seinhorst elutriator, Cobb's decanting and sieving, the Whitehead direct method (Whitehead tray), and centrifugal-flotation with silica (Ludox LS), sucrose and MgSO 4 , respectively. The most efficient methods for non-parasitic nematodes were centrifugal-flotation with silica, the Seinhorst elutriator and the Whitehead tray. Tylenchorhynchus spp. and total plant parasitic nematodes were recovered in largest numbers with the elutriator and the three centrifugation-flotation methods. The largest numbers of Pratylenchus crenatus were recovered with the Whitehead tray, while centrifugal-flotation with silica was superior for the trichodorids. Four species of endoparasitic nematophagous fungi (Catenaria anguillulae, Harposporium anguillulae, Nematoctonus leiosporus and Hirsutella rhossiliensis) were isolated from nematodes extracted with four of the six methods: the Seinhorst elutriator, the Whitehead tray, centrifugation with silica and centrifugation with sucrose. The largest numbers of infected nematodes were obtained with centrifugal-flotation with silica and the elutriation method. The smallest number of endoparasitic fungi were recovered by using Cobb's decanting and sieving and the Whitehead tray methods.