Abstract
A method for identifying individual second-stage juveniles (J2s) of three major Meloidogyne spp. in Japan was developed. Spores of three isolates of Pasteuria penetrans from Meloidogyne incognita (Mi), M. arenaria (Ma) and M. hapla (Mh) were sonicated to increase the number of spores attaching to J2s of Meloidogyne spp., they were then stained blue with Brilliant Blue G, orange with Acridine Orange, and violet with Methyl Violet, respectively. When J2s of Mi, Ma and Mh were mixed with these stained spores, each J2 was identified individually according to the color of the most abundantly attached spores on the body surface. In the case of mixed nematode suspensions containing Meloidogyne spp., free-living nematodes and Pratylenchus sp., the stained spores attached only to J2s of Meloidogyne spp., and the species of each J2 was discriminated by the spore color. This method is also applicable foridentifying individual J2s of most populations of Mi, Ma and Mh from Japan, and is useful for estimating the numbers of J2s of each Meloidogyne spp. in mixed-nematode samples.
