Nansen Christian, Zhao Genpin, Dakin Nicole, Zhao Chunhui, Turner Shane R
Department of Entomology and Nematology, UC Davis Briggs Hall, Room 367, Davis, CA, USA; School of Animal Biology, The UWA Institute of Agriculture, The University of Western Australia, Crawley, Perth 6009, Australia.
College of Information and Communication Engineering, Harbin Engineering University, Nangang District 150001, China.
J Photochem Photobiol B. 2015 Apr;145:19-24. doi: 10.1016/j.jphotobiol.2015.02.015. Epub 2015 Feb 26.
We investigated the ability to accurately and non-destructively determine the germination of three native Australian tree species, Acacia cowleana Tate (Fabaceae), Banksia prionotes L.F. (Proteaceae), and Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson (Myrtaceae) based on hyperspectral imaging data. While similar studies have been conducted on agricultural and horticultural seeds, we are unaware of any published studies involving reflectance-based assessments of the germination of tree seeds. Hyperspectral imaging data (110 narrow spectral bands from 423.6nm to 878.9nm) were acquired of individual seeds after 0, 1, 2, 5, 10, 20, 30, and 50days of standardized rapid ageing. At each time point, seeds were subjected to hyperspectral imaging to obtain reflectance profiles from individual seeds. A standard germination test was performed, and we predicted that loss of germination was associated with a significant change in seed coat reflectance profiles. Forward linear discriminant analysis (LDA) was used to select the 10 spectral bands with the highest contribution to classifications of the three species. In all species, germination decreased from over 90% to below 20% in about 10-30days of experimental ageing. P50 values (equal to 50% germination) for each species were 19.3 (A. cowleana), 7.0 (B. prionotes) and 22.9 (C. calophylla) days. Based on independent validation of classifications of hyperspectral imaging data, we found that germination of Acacia and Corymbia seeds could be classified with over 85% accuracy, while it was about 80% for Banksia seeds. The selected spectral bands in each LDA-based classification were located near known pigment peaks involved in photosynthesis and/or near spectral bands used in published indices to predict chlorophyll or nitrogen content in leaves. The results suggested that seed germination may be successfully classified (predicted) based on reflectance in narrow spectral bands associated with the primary metabolism function and performance of plants.
我们基于高光谱成像数据，研究了准确且无损地确定三种澳大利亚本土树种——考氏金合欢（豆科）、披针叶班克斯木（山龙眼科）和红千层（桃金娘科）发芽情况的能力。虽然已有针对农业和园艺种子的类似研究，但我们尚未发现任何已发表的涉及基于反射率评估树木种子发芽情况的研究。在经过0、1、2、5、10、20、30和50天的标准化快速老化处理后，对单个种子获取了高光谱成像数据（423.6纳米至878.9纳米的110个窄光谱带）。在每个时间点，对种子进行高光谱成像以获取单个种子的反射率曲线。进行了标准发芽试验，并且我们预测发芽能力的丧失与种皮反射率曲线的显著变化有关。使用正向线性判别分析（LDA）来选择对这三个树种分类贡献最大的10个光谱带。在所有树种中，经过约10 - 30天的实验老化，发芽率从超过90%降至20%以下。每个树种的P50值（等于50%发芽率）分别为19.3天（考氏金合欢）、7.0天（披针叶班克斯木）和22.9天（红千层）。基于对高光谱成像数据分类的独立验证，我们发现金合欢和红千层种子发芽情况的分类准确率超过85%，而班克斯木种子的准确率约为80%。在每个基于LDA的分类中所选的光谱带位于与光合作用相关的已知色素峰附近和/或与已发表的用于预测叶片叶绿素或氮含量的指数所使用的光谱带附近。结果表明，基于与植物初级代谢功能和性能相关的窄光谱带中的反射率，可以成功地对种子发芽情况进行分类（预测）。
