Martín-Gómez José Javier, Del Pozo Diego Gutiérrez, Tocino Ángel, Cervantes Emilio
Instituto de Recursos Naturales y Agrobiología del Consejo Superior de Investigaciones Científicas (IRNASA-CSIC), Cordel de Merinas, 40, E-37008 Salamanca, Spain.
Herbario Amazónico del Ecuador ECUAMZ, Universidad Estatal Amazónica UEA, Carretera Tena a Puyo Km. 44, Puyo EC-150950, Ecuador.
Plants (Basel). 2021 Nov 22;10(11):2546. doi: 10.3390/plants10112546.
Seed shape in species of the Cactaceae is described by comparison with geometric models. Three new groups of models are presented, two for symmetric seeds, and a third group for asymmetric seeds. The first two groups correspond, respectively, to superellipses and the combined equations of two semi-ellipses. The third group contains models derived from the representation of polar equations of Archimedean spirals that define the shape of asymmetric seeds in genera of different subfamilies. Some of the new models are geometric curves, while others are composed with a part resulting from the average silhouettes of seeds. The application of models to seed shape quantification permits the analysis of variation in seed populations, as well as the comparison of shape between species. The embryos of the Cactaceae are of the peripheral type, strongly curved and in contact with the inner surface of the seed coat. A relationship is found between seed elongation and the models, in which the genera with elongated seeds are represented by models with longer trajectories of the spiral. The analysis of seed shape opens new opportunities for taxonomy and allows quantification of seed shape in species of the Cactaceae.
通过与几何模型比较来描述仙人掌科植物种子的形状。提出了三组新模型，两组用于对称种子，第三组用于不对称种子。前两组分别对应于超椭圆和两个半椭圆的组合方程。第三组包含从阿基米德螺旋线极坐标方程表示中推导出来的模型，这些模型定义了不同亚科属中不对称种子的形状。一些新模型是几何曲线，而其他模型则由种子平均轮廓的一部分组成。将模型应用于种子形状量化可以分析种子群体的变异，以及比较不同物种之间的形状。仙人掌科植物的胚为周缘型，强烈弯曲并与种皮内表面接触。在种子伸长与模型之间发现了一种关系，其中种子细长的属由螺旋轨迹较长的模型表示。种子形状分析为分类学开辟了新机会，并能够对仙人掌科植物的种子形状进行量化。
