Determination of species and pathotypes of potato cyst nematodes in Nilgiri hills

The populations of potato cyst nematodes from six major potato growing localities of Nilgiri hills representing varying ecological conditions were characterised to species and pathotypes by using standard differential host tests. Based on the colour of developing females, on susceptible potato cultivar “Kufri Jyoti” mixed populations of Globodera pallida and G. rostochiensis from five localities and a pure population of the later species from one locality were observed. The development of females on other differential hosts indicated the presence of three pathotypes each i.e. Ro₁, Ro₂ and Ro₅ in G. rostochiensis and Pa₁, Pa₂ and Pa₃ in G. pallida.