Phenotypic variation of Zamia loddigesii Miq. and Z. prasina W.Bull. (Zamiaceae, Cycadales): the effect of environmental heterogeneity

• Published in: Plant systematics and evolution 2016-12, Vol.302 (10), p.1395-1404
• Main Authors: Limón, Francisco, González-Astorga, Jorge, Nicolalde-Morejón, Fernando, Guevara, Roger
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Environmental conditions; Environmental effects; Evolution; Generalized linear models; Genetic variation; Geography; Heterogeneity; Interspecific; Life Sciences; Morphology; Multidimensional scaling; Multivariate analysis; Original Article; Phenotypic variation; Phenotypic variations; Plant Anatomy/Development; Plant Ecology; Plant morphology; Plant Sciences; Plant Systematics/Taxonomy/Biogeography; Population characteristics; Population distributions; Population ecology; Population geography; Populations; Scaling; Species; Statistical models; Vegetation
• ISSN: 0378-2697; 1615-6110; 2199-6881
• DOI: 10.1007/s00606-016-1338-y

The study of morphological variation in heterogeneous environments provides evidence for understanding processes that determine the differences between species and interspecific adaptive strategies. In 14 populations of two closely related cycads from the genus Zamia (Zamia loddigesii and Z. prasina), the phenotypic variation was analyzed based on 17 morphological traits, and this variability was correlated with environmental conditions across the populations. Despite the significant inter-population variation observed in the two species, greater inter-specific differences were observed based on generalized linear models. Individuals of all populations except for the Macuspana (Tabasco) population of Z. prasina were separated into two discrete groups in a multivariate space (non-metric multidimensional scaling). Macuspana plants overlapped marginally with the multivariate space defined by plants in the four Z. loddigesii populations. Remarkably, Macuspana is geographically located at the distribution limits of both species that occur in close proximity expressing traits that resemble either of the two species. The heterogeneous environment seems to play a determining role in the phenotypic expression of both species. The variation found could be related to the local ecological adaptions that tend to maximize the populations adaptation.