使用JDSU公司的MicroNIR1700型微型近红外光谱仪, 研究了适合进行单籽粒玉米单倍体鉴别的光谱测量方法。 基于近红外光谱定性分析技术, 比较了漫反射和漫透射两种情况下玉米单倍体鉴别的效果。 光谱数据经过预处理后, 采用PLS＋OLDA特征提取算法, 应用SVM建立玉米单倍体鉴别模型, 分别统计漫反射和漫透射实验条件下, 鉴别模型的正确识别率。 在微型光谱仪内置光源漫反射的光谱测量方式下, 不分胚面朝向, 玉米单倍体籽粒平均识别率低于60%, 不能有效鉴别玉米单倍体和多倍体。 而采用外置光源对籽粒进行漫透射光谱测量方式, 获得了平均正确识别率为93.2%的鉴别效果, 并且模型稳定性好。 实验结果表明, 漫反射光谱仅能获得玉米籽粒表层信息, 因此玉米籽粒胚面朝向严重影响漫反射光谱鉴别单倍体种子的效果; 而漫透射光谱可以实现分析光程纵深信息全累加, 能够得到样品内部的信息, 因此对胚面朝向不敏感, 能够有效地对随机摆放的玉米单倍体和多倍体进行识别。 近红外方法能快速、无损地鉴别单倍体, 并且微型光谱仪采集速度快, 成本低, 为实现实用化的自动鉴别提供了条件。

The spectra measurements mode that suitable for haploid maize kernel identification was explored using MicroNIR-1700 series of miniature near infrared spectrometer by JDSU company. Based on Near Infrared Spectroscopy (NIRS) qualitative analysis techniques, we conducted a comparative study using reflectance and transmittance spectra to identify haploid maize kernels. Partial least squares-discriminant analysis(PLS-OLDA) was used to compress the pretreated spectral data, and then the identification models were built based on Support Vector Machine (SVM). The measured data were recorded in reflectance and transmittance modes and the recognition correct rates were calculated. For measurements taken in reflectance mode, the average recognition rate was less than 60% regardless of embryo side positions. In transmittance mode, however, the average recognition rate reached 93.2%. The experiment results show that diffuse reflection spectrum could only obtain corn grain surface information, so embryo side positions severely affect haploid maize kernel identification effect when reflectance measurements mode have been employed, but they have far less impact on transmittance mode. The near infrared diffuse transmittance spectra analyzes non-uniform samples can achieve the analysis of optical path depth information accumulation, all information of the sample interior can be obtained, so transmittance spectra could identify haploid maize effectively and be desensitized to kernel positions. NIRS qualitative analysis techniques with features of rapid, nondestructive could identify the haploid and Micro-NIR spectrometer scan fast and cost less, which have utility for automatically selecting haploid maize kernels from hybrid kernels.