Department of Physics & Astronomy, Texas A&M University, TAMU 4242, College Station, TX 77843, USA.
Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA.
Sensors (Basel). 2023 Jan 8;23(2):707. doi: 10.3390/s23020707.
Non-destructive measurements of internal morphological structures in plant materials such as seeds are of high interest in agricultural research. The estimation of pericarp thickness is important to understand the grain quality and storage stability of seeds and can play a crucial role in improving crop yield. In this study, we demonstrate the applicability of fiber-based Bessel beam Fourier domain (FD) optical coherence microscopy (OCM) with a nearly constant high lateral resolution maintained at over ~400 µm for direct non-invasive measurement of the pericarp thickness of two different sorghum genotypes. Whereas measurements based on axial profiles need additional knowledge of the pericarp refractive index, en-face views allow for direct distance measurements. We directly determine pericarp thickness from lateral sections with a 3 µm resolution by taking the width of the signal corresponding to the pericarp at the 1/e threshold. These measurements enable differentiation of the two genotypes with 100% accuracy. We find that trading image resolution for acquisition speed and view size reduces the classification accuracy. Average pericarp thicknesses of 74 µm (thick phenotype) and 43 µm (thin phenotype) are obtained from high-resolution lateral sections, and are in good agreement with previously reported measurements of the same genotypes. Extracting the morphological features of plant seeds using Bessel beam FD-OCM is expected to provide valuable information to the food processing industry and plant breeding programs.
在农业研究中，对植物材料（如种子）内部形态结构进行非破坏性测量具有重要意义。果皮厚度的估计对于了解种子的谷物质量和储存稳定性很重要，并且可以在提高作物产量方面发挥关键作用。在这项研究中，我们展示了基于光纤的贝塞尔光束傅里叶域（FD）光学相干显微镜（OCM）的适用性，该显微镜在超过~400 µm 的范围内保持几乎恒定的高横向分辨率，可直接非侵入式测量两种不同高粱基因型的果皮厚度。虽然基于轴向轮廓的测量需要额外了解果皮折射率的知识，但面内视图允许进行直接的距离测量。我们通过在 1/e 阈值处取对应于果皮的信号的宽度，以 3 µm 的分辨率从横向切片中直接确定果皮厚度。这些测量能够以 100%的准确率区分两种基因型。我们发现，为了提高采集速度和视场大小而牺牲图像分辨率会降低分类准确性。从高分辨率横向切片中获得的平均果皮厚度分别为 74 µm（厚表型）和 43 µm（薄表型），与之前对同一基因型的报告测量结果非常吻合。使用贝塞尔光束 FD-OCM 提取植物种子的形态特征有望为食品加工行业和植物育种计划提供有价值的信息。
