Diagnostic and phylogenetic significance of lateral field incisures, phasmids and other morphological characters of second-stage juveniles and males of Heteroderidae (Nematoda, Tylenchida), with notes on hosts and phylogeography

摘要

Data of the current knowledge about the number of incisures in the lateral fields of second stage juveniles and males, shape of phasmids and tip of spicules of the 158 recognised species in the 19 genera in the family Heteroderidae are reviewed and compiled. All characters are of diagnostic value in distinguishing genera and intrageneric species groups, but more detailed studies are needed. Differences in the number of incisures or in the size of phasmids among species of Cryphodera, Meloidodera and Atalodera are considered as an indication of paraphyly. In agreement with results of molecular analyses, three additional species groups are proposed for Heterodera species with Poales as hosts (Cardiolata, Koreana and Orientalis groups), and in Globodera designation of Rostochiensis, Millefolii and Zelandica groups. Information on host ranges and host reaction to parasitism has great relevance for the study of phylogenetic relationships and estimation of the age of taxa. Evaluation of biogeographical data restricted to 'natural' occurrence as well as consideration of geological and palaeoclimatic events are essential for the recovery of putative ancestral areas of origin of taxa. Heteroderid populations tentatively identified as Meloidodera, Hylonema and Sarisodera are briefly characterised from Africa (the first two genera) and Vietnam (the third genus). Other populations of unidentified species or representatives of still unknown genera are reported from Borneo, the Canary Islands, the Dominican Republic, New Zealand, Thailand, Tunisia and Vietnam.