Wang Liangju, Duan Yunhong, Zhang Libo, Wang Jialei, Li Yikai, Jin Jian
Department of Agricultural and Biological Engineering, Purdue University, 225 S. University St., West Lafayette, IN 47907, USA.
School of Industrial Engineering, Purdue University, 315 Grant St., West Lafayette, IN 47907, USA.
Sensors (Basel). 2020 Apr 13;20(8):2194. doi: 10.3390/s20082194.
Portable devices for measuring plant physiological features with their isolated measuring chamber are playing an increasingly important role in plant phenotyping. However, currently available commercial devices of this type, such as soil plant analysis development (SPAD) meter and spectrometer, are dot meters that only measure a small region of the leaf, which does not perfectly represent the highly varied leaf surface. This study developed a portable and high-resolution multispectral imager (named LeafScope) to in-vivo image a whole leaf of dicotyledon plants while blocking the ambient light. The hardware system is comprised of a monochrome camera, an imaging chamber, a lightbox with different bands of light-emitting diodes (LEDs) array, and a microcontroller. During measuring, the device presses the leaf to lay it flat in the imaging chamber and acquires multiple images while alternating the LED bands within seconds in a certain order. The results of an experiment with soybean plants clearly showed the effect of nitrogen and water treatments as well as the genotype differences by the color and morphological features from image processing. We conclude that the low cost and easy to use LeafScope can provide promising imaging quality for dicotyledon plants, so it has great potential to be used in plant phenotyping.
带有独立测量室的用于测量植物生理特征的便携式设备在植物表型分析中发挥着越来越重要的作用。然而，目前市面上这类商业设备，如土壤植物分析发展（SPAD）仪和光谱仪，都是点式测量仪，只能测量叶片的一小部分区域，无法完美代表高度多变的叶片表面。本研究开发了一种便携式高分辨率多光谱成像仪（名为LeafScope），用于在阻挡环境光的情况下对双子叶植物的整片叶子进行活体成像。硬件系统由一台单色相机、一个成像室、一个带有不同波段发光二极管（LED）阵列的灯箱和一个微控制器组成。在测量过程中，该设备将叶片压平放置在成像室内，并在几秒钟内按一定顺序交替切换LED波段的同时获取多张图像。对大豆植株进行的实验结果清楚地显示了氮素和水分处理的效果以及通过图像处理得到的颜色和形态特征所反映的基因型差异。我们得出结论，低成本且易于使用的LeafScope可为双子叶植物提供有前景的成像质量，因此在植物表型分析中具有巨大的应用潜力。
