Department of Biology, Botany Unit, University of Pisa, Pisa, Italy.
Meise Botanic Garden, Meise, Belgium.
Ann Bot. 2024 Nov 13;134(5):701-710. doi: 10.1093/aob/mcae099.
The evolutionary success of flowering plants is associated with the vast diversity of their reproductive structures. Despite recent progress in understanding angiosperm-wide trends in floral structure and evolution, a synthetic view of the diversity in seed form and function across angiosperms is lacking.
Here we present a roadmap to synthesize the diversity of seed forms in extant angiosperms, relying on the morphospace concept, i.e. a mathematical representation which relates multiple traits and describes the realized morphologies. We provide recommendations on how to broaden the range of measurable traits beyond mass, by using key morphological traits representative of the embryo, endosperm and seed coat but also fruit attributes (e.g. dehiscence, fleshiness). These key traits were used to construct and analyse a morphospace to detect evolutionary trends and gain insight into how morphological traits relate to seed functions. Finally, we outline challenges and future research directions, combining the morphospace with macroevolutionary comparative methods to underline the drivers that gave rise to the diversity of observed seed forms.
We conclude that this multidimensional approach has the potential, although still untapped, to improve our understanding of covariation among reproductive traits, and further elucidate angiosperm reproductive biology as a whole.
有花植物的进化成功与其生殖结构的多样性密切相关。尽管近年来人们对被子植物整体的花部结构和演化趋势有了深入的了解，但对种子形态和功能在被子植物中的多样性仍缺乏综合认识。
本文提出了综合现有被子植物种子形态多样性的路线图，依赖于形态空间的概念，即一个数学表示，它涉及多个特征，并描述了已实现的形态。我们建议如何通过使用代表胚胎、胚乳和种皮的关键形态特征来拓宽质量以外的可测量特征的范围，还包括果实属性（如开裂、肉质）。这些关键特征被用于构建和分析形态空间，以检测进化趋势，并深入了解形态特征与种子功能的关系。最后，我们概述了挑战和未来的研究方向，将形态空间与宏观进化比较方法相结合，以强调导致观察到的种子形态多样性的驱动因素。
我们的结论是，尽管尚未开发，但这种多维方法有可能提高我们对生殖特征之间相互关系的理解，并进一步阐明整个被子植物的生殖生物学。
