Biological characterisation of Globodera pallida from Idaho

The white potato cyst nematode, Globodera pallida, was recently found in the USA and was identified using molecular and morphometric assessment. This paper examined some biological characteristics of the Idaho population of G. pallida. The samples of the original cysts showed that they had low rates of juvenile hatch and, consequently, low rates of reproduction when compared with glasshouse-reared populations. Virulence tests using sources of partial resistance from Solanum vernei and S. tuberosum ssp. Andigena CPC 2802 compared the Idaho population to European and South American populations of G. pallida. The Idaho population showed a virulence pattern comparable to other European populations in the Pa2/3 virulence group. The overall level of reproduction of the Idaho population on the resistant cultivars was the lowest of all the populations tested, suggesting that it is not highly virulent. These results are compatible with molecular characterisation, which indicates that this population is similar to the European gene pool.