Taxonomy of the Xiphinema americanum - complex
In Italy, taxonomic studies were carried out on 39 nematode species from the Xiphinema americanum (EPPO A2 quarantine organism) complex. As reported at the 6th International Congress of Plant Pathology in Montreal, hierarchical cluster analysis of the morphometrics of the 39 species revealed the occurrence of five subgroups in which the X. americanum complex can be divided:
X. americanum:
A subgroup which contains ten species described from North America, one each from Central and South America, three from Africa, one from Asia and one from Europe.
X. brevicolle:
This subgroup is composed by two species described from Asia, two from Africa and one each from North America, South America and Europe.
X. pachtaicum:
Four species described from Europe belong to this subgroup as well as two from Asia and one each from North America and Africa.
X. lambertii:
This subgroup contains four species from Asia and one from North America.
X. taylori: The smallest subgroup containing one species from North America and one from Europe.
Sources
Lamberti, F.; Ciancio, A. (1993) Hierarchical cluster analysis to differentiate species within the Xiphinema americanum - group.
Presentation at the 6th International Congress of Plant Pathology, Montreal, CA, 1993-07/08-27/06.