2011 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to identify interspecific cotton progenies that have been converted from sterile triploids into fertile hexaploids, and to determine which chemical compounds and concentrations are most effective at producing such conversions. In addition, interspecific tetraploid breeding populations will be developed. 1b.Approach (from AD-416) Triploid progenies of Gossypium hirsutum/G. arboreum will be treated with amiprofosmethyl, colchicine, oryzalin, or trifluralin at four concentrations each. Cuttings of each triploid cross will be made and axillary buds treated with the dissolved compounds mixed in a lanolin paste. Controls will include no paste and water-lanolin. The number of self-fertile cuttings per treatment will be recorded. Chromosome counts will be conducted to confirm the ploidy of fertile plants. When tetraploid progeny of the interspecific hybrids are produced, random mated breeding populations will be developed to break up linkage blocks. 3.Progress Report During the past year, there has been no research activity related to this agreement. In 2010, we completed analysis of the last set of materials generated by a former ARS geneticist who resigned in 2007. Due to subsequent staffing vacancies, no new materials have been developed for evaluation. This project officially terminates on September 30, 2011.