Methodology for In vitro Culturing of Lesion Nematodes (Pratylenchus thornei) on Carrot Discs

摘要

Plant parasitic nematodes can feed as ectoparasites and endoparasites, their feeding habits determine the typeof planttissue requiredfortheir culture maintenance. Nematodes which feed on vascular tissue require differentiated tissues by inducing a specific host response for reproduction. In sedentary endoparasitic nematodes like Meloidogyne, Heterodera and Globodera specialized cells, giant and syncytium cells are required for reproduction. In contrast, migratory nematodes do not require vascular elements, and reproduce readily on undifferentiated callus tissue or material, such as carrot discs. The sterile carrot disc technique has successfully been employed for the monoxenic culture of economically important nematode species that multiply well andcan be cultured In vitro on carrot discs include Radopholus similis and Pratylenchus spp.; P. brachyurus, P. coffeae, P. scribneri, P. sudanensis, P. vulnus, P. zeae. Carrot discs enable the rearing of high numbers of these nematodes for timely use in experiments and for screening purposes (O ’Bannon and Taylor, 1968; Mudiope et al., 2004; Kagoda et al., 2010). Alfalfa callus tissue has also been used to culture Pratylenchus spp. monoxenically, but it can result in low populations (Motalaote et al., 1987). Hence, carrot has been shown to be a suitable medium for many migratory endoparasitic nematode species. Sterile carrot discs offer a cost effective and relatively less laborious alternative for rearing nematodes, which can result in greater nematode multiplication compared with other methods (Speijer and De Waele, 1997) and plant hosts. However, not all migratory plant-parasitic nematodes are suitable for rearing on carrot discs. Attempt to raise Helicotylenchus multicinctus (Cobb) Golden was unsuccessful (Speijer and De Waele, 1997). Therefore, the objective of this study was to assess the efficiency of sterile carrot discs for mass culturing of Pratylenchus thornei. The procedure outhned here will provide a descriptive method for multiplicationof pure cultures of P. thornei.