TERPENOIDS IN FOLIAR PIGMENT GLANDS OF A, D, AND AD GENOME COTTONS - INTROGRESSION POTENTIAL FOR PEST RESISTANCE

High-performance liquid chromatographic analyses showed that leaves of 58 accessions of 18 species of Gossypium exhibited relatively consistent differences in terpenoids among species. Cotton terpenoids, such as gossypol, are economically important secondary metabolites that accumulate primarily in gland structures throughout the plant. Color and other morphological characters associated with foliar pigment glands also were distinctive in this germplasm and could be important for taxonomic and evolutionary studies. Upland cotton (G. hirsutum) was crossed with G. raimondii, a species that produces the unique terpenoid, raimondal. In the inter-specific hybrids, we detected raimondal concentrations in leaves and flower buds that averaged 9% and 12.3%, respectively, of the level in G. raimondil. Large reductions occurred in the quantity of para-oxidation terpenoids in the hybrids in comparison to the cultivated cotton parents; these reductions were not associated with major changes in the number or size of the glands. Thus, terpenoid introgression for profile shifts are possible but will require careful progeny selection to maximize expression. © 1990 The American Genetic Association.