RESUMO
Clinanthus inflatus (Amaryllidaceae) and Ismene parviflora are described from Ancash Department in Peru. The flower of C. inflatus is urceolate, and resembles that of Urceolina (Amaryllidaceae tr. Eucharideae), a unique morphology for the genus. Ismene parviflora, with its small, loosely formed, narrowly funnelform-tubular perigone with a ventricose limb, appears to have some affinity to subgen. Pseudostenomesson and may represent an intermediate form between the former and species of subgen. Ismene. Stenomesson rubrum is transferred to Clinanthus as C. ruber on the basis of its narrowly lorate leaf morphology.
ResumenClinanthus inflatus (Amaryllidaceae) e Ismene parviflora se describen del departamento de Ancash en el Perú. La flor de C. inflatus es urceolada, y se asemeja a la de Urceolina (Amaryllidaceae tr. Eucharideae), una morfología única para el género. Ismene parviflora, con su forma suelta, perigonio angostamente funeliforme-tubular con una limbo ventricoso, parece tener alguna afinidad al subgen. Pseudostenomesson y puede representar una forma intermedia entre el primero y las especie de subgen. Ismene. Stenomesson rubrum se transfiere a Clinanthus como C. ruber, sobre la base de su morfología de hoja acintada estrecha.
RESUMO
A new saxicolous species of Amaryllidaceae tentatively assigned to the tribe Clinantheae, Pamiantheecollis Silverst., Meerow & Sánchez-Taborda, is described from the western slope of the Cordillera Occidental in the department of Cauca, Colombia. The new species differs from the two hitherto known species of Pamianthe in its yellow flowers and in its nearly obsolete perianth tube. The near loss of the perianth tube may be correlated with a change in pollinator. The new species lacks a bulb; it produces a large number of winged seeds that are wind-dispersed. A key to the species of Pamianthe is provided. This is the first record of the genus Pamianthe for Colombia. The phylogenetic position of the genus Pamianthe is discussed.
ResumenSe describe una nueva especie de Amaryllidaceae tentativamente perteneciente a la tribu Clinantheae, Pamiantheecollis Silverst., Meerow & Sánchez-Taborda, procedente de la vertiente occidental de la cordillera Occidental en el departamento del Cauca, Colombia. La nueva especie difiere de las dos especies conocidas de Pamianthe por su perianto amarillo que tiene un tubo casi ausente. La reducción del tubo del perianto probablemente tiene correlación con un cambio en el polinizador. La nueva especie carece de un bulbo, y produce numerosas semillas aladas que se dispersan por el viento. Se provee una clave a las especies de Pamianthe. Este es el primer registro del género Pamianthe para Colombia. Se discute la posición filogenética del género Pamianthe.
RESUMO
PREMISE OF THE STUDY: The Bahamas archipelago is formed by young, tectonically stable carbonate banks that harbor direct geological evidence of global ice-volume changes. We sought to detect signatures of major changes on gene flow patterns and reconstruct the phylogeographic history of the monophyletic Zamia pumila complex across the Bahamas. METHODS: Nuclear molecular markers with both high and low mutation rates were used to capture two different time scale signatures and test several gene flow and demographic hypotheses. KEY RESULTS: Single-copy nuclear genes unveiled apparent ancestral admixture on Andros, suggesting a significant role of this island as main hub of diversity of the archipelago. We detected demographic and spatial expansion of the Zamia pumila complex on both paleo-provinces around the Piacenzian (Pliocene)/Gelasian (Pleistocene). Populations evidenced signatures of different migration models that have occurred at two different times. Populations on Long Island (Z. lucayana) may either represent a secondary colonization of the Bahamas by Zamia or a rapid and early-divergence event of at least one population on the Bahamas. CONCLUSIONS: Despite changes in migration patterns with global climate, expected heterozygosity with both marker systems remains within the range reported for cycads, but with significant levels of increased inbreeding detected by the microsatellites. This finding is likely associated with reduced gene flow between and within paleo-provinces, accompanied by genetic drift, as rising seas enforced isolation. Our study highlights the importance of the maintenance of the predominant direction of genetic exchange and the role of overseas dispersion among the islands during climate oscillations.
Assuntos
Biodiversidade , Filogenia , Zamiaceae/genética , Bahamas , Variação Genética , Ilhas , Repetições de Microssatélites , FilogeografiaRESUMO
Clinanthus milagroanthus S. Leiva & Meerow, sp. nov. is described from the Department of La Libertad in Peru. The new species is most closely related to Clinanthus mirabilis (Ravenna) Meerow, with further affinities to Clinanthus viridiflorus (R. & P.) Meerow. It can be distinguished from Clinanthus mirabilis by its wider leaves, the much more brightly colored and wide spreading limb, and the much lighter colored perigone tube (yellowish green vs. dark green in Clinanthus mirabilis). A conspicuous bulge just proximal to the midpoint of the tube is a unique character of the new species.
ResumenClinanthus milagroanthus S. Leiva & Meerow, sp. nov. se describe desde el Departamento de La Libertad, Perú. La nueva especie es más estrechamente relacionada con Clinanthus mirabilis (Ravenna) Meerow, con adicionales afinidades con Clinanthus viridiflorus (R. & P.) Meerow. Se puede distinguir de Clinanthus mirabilis por sus hojas más anchas, el limbo mucho más amplio de colores brillantes, y el color de tubo perigonio mucho más claro (color amarillento vs. verde verde oscuro en Clinanthus mirabilis). Una protuberancia visible casi proximal al punto medio del tubo es un carácter único de la nueva especie.
RESUMO
PREMISE OF THE STUDY: This study of Zamia in Puerto Rico is the most intensive population genetics investigation of a cycad to date in terms of number of markers, and one of few microsatellite DNA studies of plants from the highly critical Caribbean biodiversity hotspot. Three distinctive Zamia taxa occur on the island: Z. erosa on the north coast, and Z. portoricensis and Z. pumila, both in the south. Their relationships are largely unknown. We tested three hypotheses about their genetic diversity, including the possibility of multiple introductions. METHODS: We used 31 microsatellite loci across 10 populations and analyzed the data with AMOVA, Bayesian clustering, and ABC coalescent modeling. KEY RESULTS: Puerto Rican zamias exhibit an amalgam of patterns of genetic differentiation that have been reported for cycads. Overall, the taxa are slightly inbred, with high infra-populational variation and little evidence of recent bottlenecks. Zamia erosa exhibits a more than threefold greater degree of population differentiation than the other two taxa. Admixture is evident only between Z. portoricensis and Z. pumila. Zamia portoricensis is inferred to be the youngest taxon on the island, on the basis of estimates of coalescence time and effective population size. A selective sweep may be underway in a small population of Z. erosa in a saline environment. CONCLUSIONS: Zamia erosa may represent an independent introduction into Puerto Rico; Z. portoricensis and Z. pumila fit a scenario of allopatric speciation. This will be explored further in the context of genetic analysis across the entire Caribbean region.
Assuntos
Variação Genética , Repetições de Microssatélites/genética , Modelos Genéticos , Zamiaceae/genética , Alelos , Análise de Variância , Teorema de Bayes , Análise por Conglomerados , DNA de Plantas/química , DNA de Plantas/genética , Frequência do Gene , Geografia , Dados de Sequência Molecular , Filogenia , Polimorfismo Genético , Densidade Demográfica , Dinâmica Populacional , Porto Rico , Análise de Sequência de DNA , Zamiaceae/classificaçãoRESUMO
Pseudophoenix ekmanii is a threatened palm species endemic to the Dominican Republic. Sap from trees is extracted to make a local drink; once they are tapped the individual usually dies. Plants are also illegally harvested for the nursery trade and destroyed by poachers hunting the endemic and threatened Hispaniolan parrot. We used 7 DNA microsatellite markers to assist land managers in developing conservation strategies for this palm. We sampled 4 populations along the known distribution range of this species (3 populations from the mainland and 1 from the small island of Isla Beata), for a total sample of n = 104. We found strong evidence for genetic drift, inbreeding, and moderate gene flow (i.e., all populations had at least 4 loci that were not in Hardy-Weinberg equilibrium, at least 9 loci pairs were in linkage disequilibrium, the pairwise F(ST) values ranged from 0.069 to 0.266, and had positive F(IS) values). Data supported an isolation-by-distance model, and cluster analyses based on genetic distances resolved 2 groups that match a north-south split. The population from Isla Beata had the lowest levels of genetic diversity and was the only one in which we found pairs of individuals with identical shared multilocus genotypes.