Department of Life, Health & Environmental Science, University of L'Aquila, Coppito, L'Aquila, Italy.
Majella Seed Bank, Majella National Park, Loc. Colle Madonna, Lama dei Peligni (CH), Italy.
Plant Biol (Stuttg). 2019 May;21(3):507-514. doi: 10.1111/plb.12844. Epub 2018 Jun 6.
This work aims to study seeds of the endemic species Astragalus aquilanus from four different populations of central Italy. We investigated seed morpho-colorimetric features (shape and size) and chemical differences (through infrared spectroscopy) among populations and between dark and light seeds. Seed morpho-colorimetric quantitative variables, describing shape, size and colour traits, were measured using image analysis techniques. Fourier transform infrared (FT-IR) spectroscopy was used to attempt seed chemical characterisation. The measured data were analysed by step-wise linear discriminant analysis (LDA). Moreover, we analysed the correlation between the four most important traits and six climatic variables extracted from WorldClim 2.0. The LDA on seeds traits shows clear differentiation of the four populations, which can be attributed to different chemical composition, as confirmed by Wilk's lambda test (P < 0.001). A strong correlation between morphometric traits and temperature (annual mean temperature, mean temperature of the warmest and coolest quarter), colorimetric traits and precipitation (annual precipitation, precipitation of wettest and driest quarter) was observed. The characterisation of A. aquilanus seeds shows large intraspecific plasticity both in morpho-colorimetric and chemical composition. These results confirm the strong relationship between the type of seed produced and the climatic variables.
本研究旨在研究来自意大利中部四个不同种群的特有种紫云英（Astragalus aquilanus）的种子。我们研究了种子形态-比色特征（形状和大小）以及种群之间和黑种子与白种子之间的化学差异（通过红外光谱）。使用图像分析技术测量描述形状、大小和颜色特征的种子形态-比色定量变量。傅里叶变换红外（FT-IR）光谱用于尝试种子化学特征分析。使用逐步线性判别分析（LDA）对测量数据进行分析。此外，我们分析了四个最重要的特征与从 WorldClim 2.0 提取的六个气候变量之间的相关性。种子特征的 LDA 显示出四个种群的明显分化，这可以归因于不同的化学成分，正如 Wilk 的 lambda 检验（P < 0.001）所证实的那样。观察到形态特征与温度（年平均温度、最温暖和最寒冷季度的平均温度）、比色特征与降水（年降水量、最湿润和最干燥季度的降水）之间存在很强的相关性。A. aquilanus 种子的特征表明，在形态-比色和化学成分方面都具有很大的种内可塑性。这些结果证实了所产生的种子类型与气候变量之间的强烈关系。
