Plants respond to infection by increasing the levels of several proteins, known as PR (pathogen response) proteins (Ward et al., 1991). Some of these proteins have been shown in vitro and in vivo in transgenic plants (eg Broglie et al., 1991) to have antifungal activity. Synergism between different antifungal proteins in transgenic plants has been demonstrated (Jach et al., 1995; van den Elzen et al., 1993) so the expression of several genes for antifungal proteins is probably required for significantly improved resistance to fungal pathogens. This work has received generous support from the CRDC for several years. This has allowed the generation of several batches of cotton lines expressing putative antifungal proteins. Several lines with increased chitinase activity (around ten times background levels) and expression of elevated levels of osmotin were generated. We believe that disease resistance is important for improving overall yield under low disease pressure and avoiding yield loss in cases of severe infection. Therefore evaluation of ) this material that has already been generated was of importance to the cotton industry. The main goal of this project was to generate seed for glasshouse and field testing against Verticillium and Fusarium wilts and to undertake these tests with the best chitinase-expressing material