Doubled haploids (DHs) are an important breeding tool for creating maize inbred lines. One bottleneck in the DH process is the manual separation of haploids from among the much larger pool of hybrid siblings in a haploid induction cross. Here, we demonstrate the ability of single‐kernel near‐infrared reflectance spectroscopy (skNIR) to identify haploid kernels. The skNIR is a high‐throughput device that acquires an NIR spectrum to predict individual kernel traits. We collected skNIR data from haploid and hybrid kernels in 15 haploid induction crosses and found significant differences in multiple traits such as percent oil, seed weight, or volume, within each cross. The two kernel classes were separated by their NIR profile using Partial Least Squares Linear Discriminant Analysis (PLS‐LDA). A general classification model, in which all induction crosses were used in the discrimination model, and a specific model, in which only kernels within a specific induction cross, were compared. Specific models outperformed the general model and were able to enrich a haploid selection pool to above 50% haploids. Applications for the instrument are discussed.

中文翻译：

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使用单核近红外光谱对玉米 (Zea mays subsp. mays ) 单倍体进行分类的分类方法

双单倍体 (DHs) 是创建玉米自交系的重要育种工具。DH 过程中的一个瓶颈是在单倍体诱导杂交中从更大的杂交兄弟姐妹库中手动分离单倍体。在这里，我们展示了单核近红外反射光谱（skNIR）识别单倍体核的能力。skNIR 是一种高通量设备，可获取 NIR 光谱以预测单个内核特性。我们从 15 个单倍体诱导杂交的单倍体和杂种籽粒中收集了 skNIR 数据，发现每个杂交中的多个性状（例如含油百分比、种子重量或体积）存在显着差异。使用偏最小二乘线性判别分析 (PLS-LDA)，通过它们的 NIR 配置文件将两个内核类别分开。一个通用的分类模型，其中所有的感应交叉都用于鉴别模型，而一个特定的模型，其中只有特定感应交叉内的内核，被比较。特定模型优于一般模型，并且能够将单倍体选择池丰富到 50% 以上的单倍体。讨论了该仪器的应用。