Characterization of the atypical Meloidogyne arenaria(Tylenchina: Meloidogynidae) in Japan

Genus Meloidogyneparasitizes and causes galling on host roots with heavy yield losses. Meloidogyne arenaria(Neal 1889) Chitwood 1949, one of the major species, is found in Japan and can be divided into two genotypes: M. arenariaA2-J and A2-O. Whereas the latter is typical M. arenaria, the former is empirically considered as atypical morphologically and genetically, but its detailed characteristics and phylogenetic relationships have not been described. First, we examined the perineal pattern, isozyme pattern, and PCR products with the C2F3/1108 primer set of M. arenariaA2-J and confirmed that all the populations of M. arenariaA2-J used in this study showed M. javanicaand/or M.incognita-like perineal patterns, the A2 pattern in esterase isozyme, and approx. 1.7 kb amplicon. We then carried out a phylogenetic analysis based on the sequences of a partial region of COXII-IrDNAin mitochondrial DNA to reveal the relationships between M. arenariaA2-J and related species using corresponding sequences of Meloidogyneaccessions deposited in GenBank. Moreover, host suitability of representative Solanaceae plants including Solanum torvumwas evaluated and compared to those of major species of Meloidogynecollected from Japan.