Location: Cotton Fiber Bioscience Research Unit
Title: Comparisons of methods measuring fiber maturity and fineness of Upland cotton fibers containing different degree of fiber cell wall development. Authors
Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 28, 2014
Publication Date: March 4, 2014
Citation: Kim, H.J., Rodgers Iii, J.E., Delhom, C.D., Cui, X. 2014. Comparisons of methods measuring fiber maturity and fineness of Upland cotton fibers containing different degree of fiber cell wall development. Textile Research Journal. 84:1622-1633. Interpretive Summary: The quality of yarns and fabrics depends on the physical properties of raw cotton fibers such as length, strength, maturity and fineness. Among cotton physical properties, fiber maturity and fineness have not been studied well. In addition to the conventional automated instruments such as High-Volume Instrument (HVI) and Advanced Fiber Information System (AFIS) that have been widely used to measure fiber maturity and fineness by cotton breeders and textile industry, Cottonscope has been recently developed using different technologies. Since all automated instruments were designed to measure maturity and fineness from mature and non-sticky fibers consisting of almost pure cellulose, the HVI, AFIS, and Cottonscope have not been used with developing and sticky fibers consisting of non-cellulosic sugars. Using emerging tools and techniques of molecular biology and biotechnologies, cotton scientists have tried to identify potential cotton genes affecting fiber properties from developing fibers that are live cells with the genetic materials unlike mature fibers that are dead and dried. It has been a major challenge to measure fiber properties from sticky and developing fibers due to a lack of methods for measuring fiber properties from the developing and sticky fibers. In this research, first we compared the strength and weakness of the automated instruments including HVI, AFIS, and Cottonscope with mature cotton fibers from various Upland varieties. To compare the accuracy of cotton physical property values obtained from each instrument, we also measure absolute values of maturity and fineness of mature fibers using the reference methods such as microscopic image analysis, cellulose assay, and gravimetric fineness methods. Second, we developed an optimal procedure enabling to measure fiber maturity and fineness from the developing and sticky fibers using the automated instruments. The results will enable cotton scientists to determine reliable values of fiber maturity and fineness rapidly from developing fibers, and will accelerate the progresses of cotton genomics and molecular breeding programs that need to identify genes mainly responsible for fiber maturity and fineness in developing and mature fibers.
Technical Abstract: Fiber maturity and fineness are important physical properties of cotton fibers affecting qualities of fibers and yarns. A number of direct and indirect methods are used for measuring fiber maturity and fineness from mature fibers that are thick secondary cell walls composed of almost pure cellulose. We compared the fiber maturity and fineness of the mature fibers measured with various methods such as High-Volume Instrumentation (HVI), Advanced Fiber Information System (AFIS), Cottonscope, microscopic image analysis, cellulose assay, and gravimetric fineness methods. The results obtained by the various methods correlated with one another despite different values obtained from each method. Due to the significantly different values measured between AFIS and Cottonscope, the current fiber quality rating systems developed on the basis of the AFIS values that are widely used in textile industry and cotton breeding programs could not be used for classifying the quality of cotton fibers measured by the Cottonscope. Because there is a growing need of determining the physical properties of developing fibers for cotton breeding programs, we developed a procedure measuring fiber maturity and fineness from the developing fibers that were sticky, thin, and immature at the early stage of fiber development. To measure accurate fiber properties from the developing fibers using the AFIS and Cottonscope designed to measure the mature fibers, the elimination of non-cellulosic sugars causing the stickiness in the developing fibers was crucial. The stickiness forming fiber bundles from individual fibers artificially raised the fineness values measured by Cottonscope more significantly than AFIS. In contrast, the stickiness marginally impacted the fiber maturity values measured with AFIS and Cottonscope. The results measured with HVI, cellulose analysis, and Cottonscope from the immature and/ or developing fibers were correlated with the degree of wall thickness visualized by the microscopic image analysis, but those measured with AFIS were not proportionally matched with the degree of wall thickness measured from the immature and / or developing fibers. The results will help cotton scientists selecting appropriate instruments for measuring maturity and fineness from immature and/ or developing fibers, measuring accurate fineness values from the sticky developing fibers, and interpreting maturity data measured by AFIS and Cottonscope showing significantly different values from the immature fibers.