No abstract

Genetic diversity is key in providing the variation needed to face stochastic change. Increased habitat loss alters population size and dynamics posing serious threats to the conservation of wild species. Colombia has undergone massive deforestation over the last century, but harbors extraordinary high species diversity of genus Zamia (Cycadales); however, most of the species are under threat. In this study, we targeted the largest accessible remaining populations of 2 closely related species growing as endemics in the Magdalena Valley region of Colombia. We successfully transferred the SSR loci used in previous Zamia studies to these species. In total, we amplified 13 microsatellite loci in 3 wild populations, aiming at: 1) assessing genetic diversity and 2) understanding if the structure found between the 3 populations reflected species and population boundaries due to ecological and historical genetic isolation. We found that the actual population size does not reflect population genetic diversity with a small population (Perales) harboring the highest genetic diversity. In addition, all populations are highly structured regardless of species containment, all showing signs of genetic isolation. Given the high degree of ecological threat, and the inherent biological traits of Cycads, we provide information regarding the prioritization of populations for ex situ management.

The monocot family Cyclanthaceae (Pandanales) comprises ca. 230 known species in 12 genera restricted to the Neotropics. The family has not been the subject of a species‐level molecular phylogenetic study to date, with multiple evolutionary and biogeographic questions about Cyclanthaceae still unanswered. In this study, we address genus‐ and species‐level relationships and the historical biogeography of Cyclanthaceae based on a broadly sampled molecular phylogeny. Two low‐copy nuclear genes (phyC, rpb2) and five plastid regions (atpB‐rbcL, psbA‐trnH, trnL‐trnF, trnQ‐rps16, matK) representing 99 species and all genera of Cyclanthaceae were sampled, spanning the taxonomic and biogeographic diversity of the family. Our results strongly support the monophyly of all Cyclanthaceae genera and confirm previously proposed hypotheses of intergeneric relationships. Infrageneric relationships are generally well supported, with some exceptions in the genus Asplundia that may require a broader sampling to clarify. The early diversification of Cyclanthaceae is estimated to date back to the Paleocene‐Eocene period in South America, where the family possibly arrived through a boreotropical route. The origin of most genera is inferred from the Paleocene of the Tumbes‐Chocó‐Magdalena region, possibly indicating an earlier origin for this biodiversity hotspot. The current distribution of Cyclanthaceae is likely to have been strongly influenced by major biogeographical events in the Neotropics, such as the uplift of the Andes and the opening of the South America dry diagonal. Further studies that include a broader sample of the large Asplundia‐Dicranopygium clade and Sphaeradenia group are required.

Wild plant species with potential for use as ornamental green foliage are often reported. Nevertheless, there are few studies evaluating morphological and anatomical aspects associated with this use. Preliminary trials suggest that the species of Sphaeradenia (Sander ex Mast.) Harling, a Cyclantaceae that occurs from Costa Rica to Peru, is suitable to be used as fresh foliage because of attractiveness of their leaves in vase and its durability without showing tissue damage, compared with other genera of this family. Through the study of anatomical characters, it is possible to predict the potential of a species that can serve as ornamental foliage. In this study, three foliar anatomical features (thickness of the cuticle and leaf, and percentage of fibers in the mesophyll) of seven Cyclanthaceae species were evaluated, using anatomical techniques and image analysis with the LUCIA® and ImageJ softwares. Statistical analysis of the results suggests that this high durability is associated with the thickness of the cuticle and mesophyll, but not with the amount of fibers in the leaf.