| 摘要: |
| 【 目的】 借助近红外光谱（near infrared spectroscopy，NIRs）信息分析柠檬桉（Corymbia citriodora Hook. ）不同种源间的亲缘关系，探索NIRs用于其遗传信息分析的可行性和准确性。【 方法】以国家桉树种质资源库保存的柠檬桉10个种源家系材料为研究对象，每个种源按照广泛性和代表性的取样原则共采集296个家系的叶样，每个家系仔细选择6-10片外形健康、生理条件一致的叶片，烘干、粉碎后装袋，采用便携式近红外光谱仪Phazir Rx采集叶片粉样的NIRs信息。NIRs数据经 Savitzky-Golay平滑二阶导数预处理后，建立柠檬桉种源的主成分分析（PCA）模型。通过无监督的判别分析（SIMCA），估算10个种源两两之间的NIRs光谱距离。基于NIRs光谱距离构建各种源的层级聚类树。通过不同波长建模能力（modeling power）分析，解析柠檬桉种源间遗传差异的物质基础。【 结果】NIRs能够有效量化并区分柠檬桉种源。各种源间的NIRs欧氏距离为0.016~0.024，并将10个种源明确地划分为澳大利亚原生和国内引种两大组，且原生种源的聚类关系与其地理分布高度吻合，为追溯国内引种种源的来源提供了直接证据。SIMCA进一步证实，即使是NIRs光谱距离相近的种源，其包含的296个家系样本也能被彼此模型清晰、准确分类。建模能力分析显示，1 708~1 785，1 880~1 935 及 2 292~2 370 nm 3个波段的建模能力尤为突出，其分别对应纤维素、半纤维素和C―H基团等关键化学成分的特征吸收峰，而种源间这些化合物或基团的差异很可能是其遗传分化的根源。【 结论】NIRs分析能有效解析柠檬桉种源间的亲缘关系和地理分化信息，为厘清国内早期引种材料的来源问题提供了新的技术方案。 |
| 关键词: 柠檬桉 遗传背景 近红外光谱（NIRs） 光谱距离 层级聚类 判别分析 |
| DOI：10. 13207/j. jnwafu. 2026. 09. 006 |
| 分类号: |
| 基金项目:广东省林业科技创新项目（2023KJCX012）；国家重点研发计划子课题（2022YFD2200203-3）；广东省自然科学基金项目（202? 1A1515010618） |
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| Near infrared spectroscopy analysis of the genetic background of Corymbia citriodora provenances |
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LIN Yan1, LU Wanhong1, ZHAI Jiangbo1, LIU Guo1, LUO Jianzhong1, ZHANG Peng2
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1.Research Institute of Fast-growing Trees，Chinese Academy of Forestry，Zhanjiang，Guangdong 524022，China;2.Huangshi Pengcheng Junior High School，Huangshi，Hubei 435100，China
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| Abstract: |
| 【 Objective】This study aims to analyze the genetic relationships among different provenances of Corymbia citriodora using near-infrared（NIR） spectral data，and to explore the feasibility and accuracy of applying NIR for genetic analysis.【Method】The study utilized genetic materials from 10 provenances of C.citriodora preserved in the National Eucalypt Germplasm Repository. Based on the principles of representativeness and broad sampling，leaf samples from 296 families were collected. For each family，6-10 healthy leaves with consistent physiological conditions were carefully selected，dried，ground，and packed into plastic self sealing bags. NIRs of the powdered samples were acquired using a portable NIR spectrometer（Phazir Rx）.After pre?treating the original spectra with Savitzky-Golay second derivative smoothing，a principal component analysis （PCA） model was established. Spectral distances between each pair of the 10 provenances were estimated using Soft Independent Modeling of Class Analogy（SIMCA），an unsupervised discriminant analysis method. A hier-archical clustering tree of provenances was then constructed based on the NIRs distances. Furthermore，the analysis of modeling power at different wavelengths were conducted to elucidate the chemical basis of genetic variations among provenances.【Result】NIRs proved effective for quantifying and distinguishing C.citriodora provenances. The Euclidean spectral distances among provenances ranged from 0. 016 to 0. 024，clearly clustering the ten provenances into two main groups：native Australian and domestic introduced provenances. The clustering pattern of native provenances strongly aligned with their geographic distribution，providing direct evidence for tracing the origins of the introduced germplasms in China. SIMCA analysis further confirmed that the 296 family samples could still be accurately and distinctly classified by their respective models，even for closely related provenances with similar spectral distances.Modeling power analysis highlighted three spectral ranges with particularly high discriminatory power：1 708-1 785，18 80-1 935，and 2 292-2 370 nm. And these waves cor?responded to the characteristic absorption peaks of key chemical compounds and functional groups，namely cellu?lose，hemicellulose，and C―H groups，respectively. The differences in these compounds or functional groups among provenances were likely be the inner reasons of genetic differentiation on C.citriodora.【Conclusion】The present study showed that NIR can effectively reveal the genetic relationships and geographic differentiation among provenances of C.citriodora，which provided a novel solution for clarifying genetic origins of early-intro?duced germplasm of this species in China. |
| Key words: Corymbia citriodora Hook. genetic background near-infrared spectroscopy（ NIRs） spectral distance hierarchical clustering discriminant analysis |
