Gametogenesis and the Chromosomes of Meloidogyne nataliei: Not Typical of Other Root-knot Nematodes.
Studies of oogenesis and spermatogenesis revealed that Meloidogyne nataliei is a diploid, amphimictic species with four (n), relatively large chromosomes, and possibly with an XX female symbol-XY male symbol mechanism of sex determination. It differs considerably from all other amphimictic, or meiotically parthenogenetic, species of Meloidogyne which have 13-18 smaller chromosomes and from Meloidogyne (Hypsoperine) spartinae which has seven. Consequently, the taxonomic position of M. nataliei needs to be re-evaluated. The chromosomes of M. nataliei and their behavior during gametogenesis resemble more closely chromosomes of the genus Heterodera than those of the genus Meloidogyne. This resemblance, however, may not imply a closer phyletic relationship of M. nataliei to heteroderid nematodes.
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