INTERSPECIFIC AND INTRASPECIFIC VARIATION BETWEEN POPULATIONS OF GLOBODERA-ROSTOCHIENSIS AND GLOBODERA-PALLIDA REVEALED BY RANDOM AMPLIFIEDPOLYMORPHIC DNA

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