RFLP analysis in Canary Islands and north European populations of potato cyst nematodes (Globodera spp.): hybridization with cloned fragments.

Abstract

Four random probes from a Globodera pallida DNA library and one rDNA repeat probe from flax were used to highlight specific fragments in total DNA restricted with the endonucleases Bam HI, Eco RI, Eco RV, and Hind III, from 26 potato cyst nematode (PCN) populations (G. rostochiensis and G. pallida). The percentage similarity between species was low (%sm = 45.6). Cluster and principal coordinate analysis allowed us to hypothesise about the epidemiology of these populations. In the G. rostochiensis group, the populations representing pathotypes Ro2, Ro3, Ro4 and Ro5 may have been derived from the same introduction. Canarian populations R1, R2, R6, R7, and R10 were distinct from all the controls but R4 and R5 were close to the British Ro1 population. In the G. pallida group, the Luffness population was distinct from all others suggesting that it may represent a distinct introduction of PCN into the British Isles. Canarian population P9 had ten markers which were absent from the European control populations and it is possible that this population represents a distinct introduction of G. pallida into the Island of Tenerife.