Species delimitation in Ceratozamia (Zamiaceae) from Southwestern Mexico, in light of reproductive and climatic diversification
Species delimitation in Ceratozamia (Zamiaceae) from Southwestern Mexico, in light of reproductive and climatic diversification
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根据生殖和气候多样化对墨西哥西南部的 Ceratozamia（Zamiaceae）进行物种界定
DOI：
10.1007/s13127-022-00598-0
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发表时间：
2023
影响因子：
1.6
通讯作者：
Stevenson, Dennis Wm.
中科院分区：
文献类型：
--
作者：
Martínez-Domínguez, Lilí;Nicolalde-Morejón, Fernando;Vergara-Silva, Francisco;Guevara, Roger;Gernandt, David S.;Stevenson, Dennis Wm.
多学科分类学研究增强了复杂分类群内物种的界定。在苏铁属角藻属中，已提出的几个物种复合体的分类学仍未完全解决。五种角蝽属分布在墨西哥西南部的索科努斯科地区，地理上邻近。由于这些物种之间的相似性和不同的形态，它们的分类是一个混乱的根源。基于综合分类学，包括形态学（定性和定量）、生态和分子数据，我们旨在诊断索科努斯科地区的物种。我们进行了广泛的实地采样，从总共 12 个种群中收集了 225 只个体，并审查了 100 个植物标本，以评估该物种是否可诊断。我们在种群水平上对营养和生殖特征进行了形态测量分析，并首次对新热带苏铁植物的花粉和排卵球果的表型变异进行了分析。此外，我们评估了气候因素对形态变化的影响。排卵球果的形态特征与气候条件相关。相比之下，球果花粉形态与环境之间不存在显着相关性。在花粉球果中，我们发现了可以识别物种的固定特征。单倍型网络显示了几组相关的单倍型，在某些物种中对应于混合种群集群。我们发现表型和遗传证据之间存在不一致。证据的整合为澄清物种边界和概述物种之间的差异提供了基础观点，我们将其纳入分类学索引中。一般来说，这组物种内的混合关系可能是由于共同物候和共享生物授粉载体所支持的历史杂交事件。最后，根据我们的结果，我们讨论了形态学在苏铁科植物物种界定和进化关系推断中的应用。
Multidisciplinary taxonomic studies have enhanced the delimitation of species within complex taxonomic groups. In the cycad genusCeratozamia, the taxonomy is still not fully resolved for the several species complexes that have been proposed. FiveCeratozamiaspecies occur in geographic proximity in the Soconusco region of southwestern Mexico. Because of similarity and variable morphology across these species, their taxonomy is a source of confusion. Based on integrative taxonomy, including morphological (qualitative and quantitative), ecological, and molecular data, we aimed to diagnose the species from the Soconusco region. We carried out extensive field sampling, collecting 225 individuals from a total of 12 populations, and reviewed one hundred herbarium specimens to evaluate whether the species are diagnosable. We carried out morphometric analyses at the population level on vegetative and reproductive characters and present the first analyses of phenotypic variability of pollen and ovulate strobili in neotropical cycads. Additionally, we evaluated the influence of climatic factors on morphological variation. Morphological characters of ovulate strobili were correlated with climatic conditions. In contrast, there was no significant correlation between the morphology of pollen strobili and the environment. In the pollen strobili, we found fixed characters that allow for the identification of the species. The haplotype networks displayed several groups of related haplotypes, which in some species corresponded to mixed population clusters. We detected a discordance between phenotypic and genetic evidence. The integration of evidence offers grounded views for clarifying species boundaries and outlining the differences among species, which we incorporated into a taxonomic key. In general, the mixed relations within this group of species may be due to historical hybridization events favored by common phenology and sharing of biotic pollination vectors. Finally, based on our results, we discuss the use of morphology for species delimitation and inference of evolutionary relationships in cycads.