The relationship between species within theXiphinema americanum‐group (Nematoda: Dorylaimida)1

摘要

Principal components and hierarchical cluster analysis based on morphometric characters of the type populations of the 39 species attributed to theXiphinema americanum‐group confirmed the occurrence of five subgroups. The use of a single character is generally insufficient to characterize a species because of the wide intra‐population and intra‐specific variations. Hierarchical cluster analysis, although impractical for species/population identification, appears useful in the study of the relationships between species or groups of sp