ABSTRACT

Two cotton lines were transformed with a bean chitinase (ch5b) and one of the lines with -1,3 glucanase (bg). Individuals of each transformation were tested for presence of the gene, increased and tested in a greenhouse assay for activity against Rhizoctonia solani. The lines with the best apparent resistance were increased and tested in three replicated field trials, which also included the original parent and commercial variety Paymaster HS-26. At sites which was predominantly affected by Thielaviopsis basicola, Meloidogyne incognita, and Rotylenchulus reniformis, there were no benefit or detriment of the transformed genes on root necrosis or nematode population density. At a site dominated by Verticillium dahliae, several of the transformed breeding lines to the more wilt susceptible parent became more resistant and one line became more susceptible as compared to the nontransformed parent. For more wilt resistant parent, transformed lines either had equal or higher susceptibility to wilt than the nontransformed parent.