| The quality demands of cotton have shifted from length to strength in the last fifty years. Unlike synthetics, which are "made" to the specific demands of textile mills, cotton must be genetically improved to meet textile demands. Breeders must improve fiber parameters without affecting potential yield, and this required years of crossing and phenotypic selection. With recent developments in biotechnological techniques, identification of genes controlling specific traits makes cultivar improvements easier, less time consuming, and more successful.;A population of Tamcot 2111/Pima S-6/*3/Tamcot 2111 was developed in an attempt to introgress alleles that confer fiber strength and other fiber properties from Pima S-6 into Tamcot 2111, a higher yielding, high quality G. hirsutum cultivar. Twenty-four BC3F2 ⊗ families, comprised of 22 to 185 plants, were evaluated phenotypically and genotypically to determine introgression of Pima S-6 fiber genes into the Tamcot 2111 recurrent parent and identify informative RFLP markers for future cultivar development. The BC3F2 open pollinated progeny of these families were evaluated phenotypically and agronomically also to determine introgression and whether marker detection of loci held true in the field.;The extent of introgression in the BC3F2 ⊗ families varied from 0.7% to 9.0% and from 0.0% to 6.53% in individual plants within families. Only one family had the expected amount of G. barbadense chromatin, three had more than 6.25% chromatin introgressed, and 20 families had less than the theoretical amount.;Family 94-33 showed promise to improve yield while maintaining the recurrent parent's fiber properties. Family 94-15 showed promise to improve fiber fineness without sacrificing yield potential. Family 94-34 appears to be an excellent source of Pima length genes, and Family 94-10 appears to be a source of elongation, but with a possible yield penalty.;Of the two-hundred-and-sixty-two markers used to hybridize the twenty-four families, only thirteen showed linkage to specific fiber properties. Markers Al535aE5 and pAR504E6C are linked to Pima QTLs that may be used to improve lint yield and marker pAR792E3C is linked to a micronaire G. barbadense QTL. The other ten markers were G. hirsutum markers that may be used to improve G. barbadense cultivars. |
