Maturity is a major fiber trait that affects the processing and performance of cotton fiber. Rapid and accurate identification of fiber maturity phenotypes and genotypes is of importance to breeders. Previous studies showed that either conventional fiber measurements or attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) analysis discriminated the immature fiber (im) phenotype from the wild type (WT) mature fiber phenotype in a segregating F2 population from a cross between two upland cotton lines differing in fiber maturity. However, both conventional fiber property measurement methods and FT-IR analyses with current algorithms could not detect the subtle differences among the WT fibers composed of two different genotypes, WT homozygosity (WT-homo) and WT heterozygosity (WT-hetero). This research explored the FT-IR method, in combination with soft independent modeling of class analogy of principal component analysis (SIMCA-PCA), for the discrimination of WT fiber phenotypes consisting of two different genotypes (WT-homo and WT-hetero). The new approach enabled the detection of IR spectral intensity differences between WT-homo and WT-hetero fibers. Successful classification originated from a distinctive spectral difference in the low-wavenumber region (<700 cm-1) between WT-hetero fibers and WT-homo fibers. This observation emphasized that ATR FT-IR with a SIMCA-PCA approach would be a sensitive tool for classifying the WT fibers demonstrating minor phenotypic differences. The improved sensitivity of the infrared method may provide a way of dissecting genotype-phenotype interactions of cotton fibers rapidly and efficiently.

中文翻译：

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衰减全反射傅里叶变换红外光谱与类别类比软独立建模-主成分分析对不同基因型组成的棉花群体的棉纤维成熟表型进行分类。

成熟度是影响棉纤维加工和性能的主要纤维性状。快速准确地鉴定纤维成熟度表型和基因型对于育种者来说非常重要。先前的研究表明，无论是传统的纤维测量还是衰减全反射傅里叶变换红外光谱（ATR FT-IR）分析都可以将未成熟纤维（im）表型与野生型（WT）成熟纤维表型区分开来，从F2群体中分离出杂交纤维成熟度不同的两个陆地棉品系。然而，传统的纤维性能测量方法和使用当前算法的FT-IR分析都无法检测由两种不同基因型WT纯合性（WT-homo）和WT杂合性（WT-hetero）组成的WT纤维之间的细微差异。本研究探索了 FT-IR 方法与主成分分析类别类比的软独立建模 (SIMCA-PCA) 相结合，用于区分由两种不同基因型（WT-同源和 WT-异质）组成的 WT 纤维表型。新方法能够检测 WT 同质光纤和 WT 异质光纤之间的红外光谱强度差异。成功的分类源于 WT 异质纤维和 WT 均质纤维在低波数区域 (<700 cm-1) 的独特光谱差异。这一观察结果强调，采用 SIMCA-PCA 方法的 ATR FT-IR 将成为对表现出微小表型差异的 WT 纤维进行分类的敏感工具。红外方法灵敏度的提高可以提供一种快速有效地剖析棉纤维基因型-表型相互作用的方法。