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Use of esterase patterns of females and galled roots for the identification of species of Meloidogyne

1993; Brill; Volume: 16; Issue: 2 Linguagem: Inglês

1164-5571

S. K. Ibrahim, R. N. Perry,

Legume Nitrogen Fixing Symbiosis

The impact of root-knot nematodes (Meloidogyne spp.) on crops and the relationship between nematode and host differ bet\veen species. Thus, accurate identification is important but the use of morphological techniques is very difficult, even for weil qualified taxonomists (Eisenback, 1985; Hirschmann, 1985; Hussey, 1990). Isozyme electrophoresis using nonspecific esterase patterns can distinguish between different species (Hussey el al., 1972; Dalmasso & Berge, 1978, 1983; Janati el al., 1982; Fargette, 1987a; Nobbs el al., 1992) and has been reported ta be a reliable diagnostic character for species identification (Esbenshade & Triantaphyllou, 1990). Detection of esterase activity using electrophoresis techniques involves obtaining females either by using chemical macerating enzymes (Hussey, 1971) or root dissection Qones, 1980); both approaches require considerable time to obtain sufficient material. Dissection of the giant cell complex is difficult at the early stage of infection and more difficult later when lateral roots emerge and adult female nematodes rupture easily Qones, 1980). Ishibashi (1970) and Berge and Dalmasso (1975) reported that esterase patterns of Meloidogyne females dissected from galled roots varied when nematodes were cultured on different hosts. By contras t, Dickson el al. (1971), Hussey el al. (1972), Fargette (1987b) and Pais and Abrantes (1989), working with different populations of the same species, failed ta show host-induced differences in esterase patterns. The objective of this study was to determine if galled roots can be used as the basis of a rapid technique to detect esterase activity of female Meloidogyne, thus avoiding the need to separate females from the roots. Using this method, the consistency of patterns from M. javanica, M. incognita and M. arenaria on three different hosts was also examined.