Inter- and intraspecific variation between populations of G. rostochiensis and G. pallida revealed by Random Amplified Polymorphic DNA

The genetic relationships between populations of the potato cyst nematode species Globodera rostochiensis and G. pallida were analyzed using random amplified polymorphic DNA (RAPD). Only nine of 250 amplified DNA fragments were common to both species. The intraspecific variation was small. The proportions of shared DNA fragments among G. rostochiensis populations ranged from 0.870 to 0.967 and those for G. pallida populations, from 0.829 to 1.000. Unweighted pair group method with arithmetic mean analysis of RAPD data showed that G. rostochiensis populations cluster in groups with similar pathotype designations. No similarity between RAPD data and pathotype classifications of the G. pallida populations was found. The origin of the observed inter- and intraspecific variation and the value of the RAPD technique to determine these variations are discussed.