This project had two major aims consistent with the overall goal of controlling Verticillium wilt in cultivated cotton (Gossypium hirsutum). The first aim was to employ molecular genetic techniques to differentiate between isolates of the fungal pathogen Verticillium dahliae in order to develop a better understanding of the epidemiology of Verticillium wilt disease in cotton. The second aim was to produce molecular genetic fingerprints of the wilt-tolerant cotton cultivars currently being developed by the CSIRO to assist in the identification and tracking of potential genes for disease resistance in the plant breeding program.