** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** IMPROVING FIBER QUALITY IS ESSENTIAL IF COTTON WANTS TO CONTINUE TO REMAIN COMPETITIVE AGAINST MAN-MADE FIBERS. IN PARTICULAR, YARN QUALITY NEEDS TO BE IMPROVED TO TAKE ADVANTAGEOF RECENT INNOVATIONS WITH VORTEX SPINNING TECHNOLOGY. OUR CURRENT SYSTEM OF QUANTIFYING AND APPLYING A MONETARY VALUE TO COTTON FIBER QUALITY IN THE MARKETPLACE USES HVI MEASUREMENTS, WHICH FAILS TO CAPTURE MANY IMPORTANT FIBER CHARACTERISTICS THAT AFFECT YARN QUALITY. AFIS MEASUREMENTS CAN EVALUATE A WIDER RANGE OF FIBER CHARACTERISTICS AND IS SUPERIOR AT PREDICTING SPINNING PERFORMANCE. UNFORTUNATELY, AFIS IS A MUCH SLOWER AND MORE EXPENSIVE METHOD OF FIBER ANALYSIS COMPARED TO HVI AND PROHIBITIVE FOR WIDE-SPREAD USE IN COTTON BREEDING PROGRAMS, THEREFORE EFFECTIVE SNP MARKERS COULD REDUCE THE COST AND IMPROVE THE EFFICACY OF SELECTING LINES WITH IMPROVED FIBER QUALITY. IT IS THE GOAL OF THIS PROJECT TO IDENTIFY QTL MARKERS ASSOCIATED WITH AFIS FIBER MEASUREMENTS WITH THE 63 K SNP ARRAY IN TWO SEGREGATING POPULATIONS, ONE WITH HIGH QUALITY FIBER AND ANOTHER WITH LOW QUALITY FIBER. FIBER TRAITS QUALITYWILL BE MEASURED FROM MULTIPLE GENERATIONS OF THE POPULATION IN MODERATE TO LOW STRESS ENVIRONMENTS. THIS WILL ALLOW US DETERMINE A LARGE AMOUNT OF GXE EFFECTS THAT OFTEN CONFOUND THE USE OF QTL MARKERS ASSOCIATED WITH FIBER TRAITS. WE HOPE TO IDENTIFY EARLY GENERATION FIELD CONDITIONS THAT WOULD ALLOW THESE TYPES OF QTL MARKERS TO BE PORTABLE ACROSS POPULATIONS AND ENVIRONMENTS, WHICH WOULD IN TURN LEAD TO FASTER AND MORE PRECISE IMPROVEMENTS IN FIBER QUALITY?.