Breeding for improved yarn quality: Modifying fiber length distribution

For the last two decades, cotton breeders have used HVI (High Volume Instrument) as their primary and often sole source of fiber quality data when making plant selections. Fiber data generated by Advanced Fiber Information System technology is also now available to plant breeders, and provides additional information on length characteristics and fiber maturity. Two methods of evaluating fiber quality of upland cotton (Gossypium hirsutum L.) in a breeding program were compared. Yarn quality of cottons selected using data from each of these methods was evaluated. One method used only HVI data for plant selections while the other method used only data from AFIS. One critical difference between the selection methods was the use of fiber length distributions as the only selection criteria in the AFIS method. Line development began with 15 intraspecific F ₂ populations in 2005. Selections were made in the F ₂ and F ₃ generations using fiber data generated from either HVI or AFIS instruments. Evaluation continued until F ₅ lines were selected in 2007. In the F ₅ generation, 10 lines from each selection method and 4 commercial varieties were planted at three locations. Whole plots were harvested for each location and carded 30Ne count ring spun yarns were produced from each of the F ₅ breeding lines and 4 commercial varieties. Yarn properties evaluated include elongation, single end tenacity, work of rupture, coefficient of variation, thin places, thick places, neps, and hairiness.Both selection methods resulted in F ₅ lines with better fiber quality and yarn quality than commercial varieties. F ₅ lines from both methods had lower short fiber content by number, SFCn, than the commercial varieties. Yarn tenacity, elongation, CV, thin places were all improved by both selection methods compared to commercial varieties. Results from different locations indicate fiber maturity has a significant impact on various fiber and yarn properties. Fiber and yarn data indicate it is possible to improve fiber length distribution using either selection method.It is important for breeders to understand the relationships that exist between overall fiber quality, specific fiber properties, and yarn quality. All of these factors interact and are critical to the development of cottons that can compete in a global market. Understanding these interactions will allow breeders to more effectively use fiber data, from HVI or AFIS, for selection purposes to improve yarn quality.