Location: Commodity Utilization ResearchTitle: Surface and thermal characterization of cotton fibers of phenotypes differing in fiber length
Submitted to: Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2021
Publication Date: 3/24/2021
Citation: He, Z., Nam, S., Fang, D.D., Cheng, H.N., He, J. 2021. Surface and thermal characterization of cotton fibers of phenotypes differing in fiber length. Polymers. 13(7). Article 994. https://doi.org/10.3390/polym13070994.
Interpretive Summary: Cotton is a well-traded agricultural commodity primarily for textile fiber purposes. As fiber length is very important to the quality of textiles, understanding the genetics and physiology of cotton fiber elongation can provide valuable tools to the cotton industry by targeting genes or cropping factors responsible for fiber yield and quality. Cotton fiber mutants provide such a resource for the elucidation of fiber development mechanisms owing to the structural, morphological, and biochemical variances in the relevant fiber cells. In this work, we collected the matured fiber samples from a WT cotton and three cotton mutants producing short lints (Li1, Li2, and Liy). The surface and thermal characteristics of these fiber samples were investigated by multiple advanced instrumental techniques. Systematic comparison found the distinct presence of Ca in the surface composition of naturally occurred mutant Li2-short and man-made mutant Liy, corresponding to the much closer similarity of two samples in other measured parameter than other three samples. This observation suggested that Ca-enhanced rigid cell wall structures had limited the fiber elongation in the two mutants. While the elongation inhibitory mechanisms should be different in other three naturally occurred mutants, no clear evidence was found to link their phenotype properties measured in this study to any potential genetic mutation clues. This work provided new clues to establish links of those fiber-related trait loci with functionally diverse but coordinately regulated genes for cotton elongation and quality.
Technical Abstract: Cotton is one of the most important and widely grown crops in the world. Understanding the synthesis mechanism of cotton fiber elongation can provide valuable tools to the cotton industry for improving cotton fiber yield and quality at the molecular level. In this work, the surface and thermal characteristics of cotton fiber samples collected from a wild type (WT) and three mutant lines (Li1, Li2-short, Li2-long, Li2-mix, and Liy) were comparatively investigated. Microimaging revealed a general similarity trend of WT = Li2-long ˜ Li2-mix > Li1 > Li2 short ˜ Liy with Ca detected on the surface of the last two. Attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and thermogravimetric measurements also showed that Li2-short and Liy were more similar to each other, and Li2-long and Li2-mix closer to WT while Li1 was quite independent. FT-IR results further demonstrated that wax and amorphous cellulose were co-present in fiber structures during the fiber formation processes. Correlation analysis found that the FT-IR-based maturity parameter was well correlated (p = 0.05) to the onset decomposition temperature and all three weight-loss parameters at onset, peak, and end decomposition stages, suggesting that the maturity degree is a better parameter than crystal index (CI) and other FT-IR parameters that reflect the thermal stability of the cotton fiber. In summary, this work demonstrated that genetic mutation altered the surface and thermal characteristics in the same way for Li2-short and Liy, but with different mechanisms for the other three mutant cotton fiber samples.