Patricio Peñailillo

Relationships and genetic consequences of contrasting modes of speciation among endemic species of Robinsonia (Asteraceae, Senecioneae) of the Juan Fernández Archipelago, Chile, based on AFLPs and SSRs

This study analyses and compares the genetic signatures of anagenetic and cladogenetic speciation in six species of the genus Robinsonia (Asteraceae, Senecioneae), endemic to the Juan Fernández Islands, Chile. Population genetic structure was analyzed by amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) markers from 286 and 320 individuals, respectively, in 28 populations. Each species is genetically distinct. Previous hypotheses of classification among these species into subgenera and sections, via morphological, phytochemical, isozymic and internal transcribed spacer (ITS) data, have been confirmed, except that R. saxatilis appears to be related to R. gayana rather than R. evenia. Analysis of phylogenetic results and biogeographic context suggests that five of these species have originated by cladogenesis and adaptive radiation on the older Robinson Crusoe Island. The sixth species, R. masafuerae, restricted to the younger Alejandro Selkirk Island, is closely related to and an anagenetic derivative of R. evenia from Robinson Crusoe. Microsatellite and AFLP data reveal considerable genetic variation among the cladogenetically derived species of Robinsonia, but within each the genetic variation is lower, highlighting presumptive genetic isolation and rapid radiation. The anagenetically derived R. masafuerae harbors a level of genetic variation similar to that of its progenitor, R. evenia. This is the first direct comparison of the genetic consequences of anagenetic and cladogenetic speciation in plants of an oceanic archipelago.

EL GENERO JARAVA RUIZ ET PAV. (STIPEAE-POACEAE): DELIMITACION Y NUEVAS COMBINACIONES

Se reconoce para America del Sur el genero Jarava Ruiz et Pav. Este genero incluiria a todas aquellas especies tratadas frecuentemente por los agrostologos sudamericanos dentro de Stipa L. s.l. cuyos antecios presentan rasgos morfologicos asociados a una anemocoria especializada (Stipa subgen. Jarava, Stipa subgen. Ptilostipa y Stipa subgen. Pappostipa). La presencia de pelos largos en el apice de la lema formando un pappus, o bien, de aristas plumosas o paposas, se interpretan como novedades evolutivas, es decir, caracteres avanzados a una dispersion de las diasporas por el viento. Tambien, se incluyen dentro de Jarava aquellas especies que han evolucionado hacia una cleistogamia aerea axilar. Se realiza una enmienda del genero y se dan a conocer las nuevas combinaciones

Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernandez Archipelago, Chile

A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Genetic variation (AFLPs and nuclear microsatellites) in two anagenetically derived endemic species of Myrceugenia (Myrtaceae) on the Juan Fernández Islands, Chile

PREMISE OF THE STUDY Anagenesis (or phyletic evolution) is one mode of speciation that occurs in the evolution of plants on oceanic islands. Of two endemic species on the Juan Fernández Islands (Chile), Myrceugenia fernandeziana and M. schulzei (Myrtaceae), believed to have originated anagenetically from different continental progenitors, the first is endemic to Robinson Crusoe Island and has no clear tie to continental relatives; the last is endemic to the younger island, Alejandro Selkirk Island, and has close affinity to M. colchaguensis in mainland Chile. METHODS Using AFLPs and six nuclear microsatellites from 381 individuals representing 33 populations, we determined patterns of genetic variation within and among populations on both islands and between those of the islands and mainland. KEY RESULTS Considerable genetic variation was found within populations on both islands. The level of gene diversity within M. schulzei was equivalent to that of its close continental relative M. colchaguensis. Genetic diversity was not partitioned geographically in M. fernandeziana and was weakly so and nonsignificantly in M. schulzei. CONCLUSIONS The high genetic variation in both taxa is most likely due to anagenetic speciation. Subsidence of the older island Robinson Crusoe, landscape erosion, and restructuring of communities have severely reduced the overall island population to a single panmictic system. On the younger and less modified Alejandro Selkirk Island, slightly stronger patterns of genetic divergence are seen in M. schulzei. Because both species are genetically diverse and number in the thousands of individuals, neither is presently endangered in the archipelago.

Genetic consequences of cladogenetic vs. anagenetic speciation in endemic plants of oceanic islands

This paper presents for the first time a comparison of the genetic consequences of two different types of speciation in plants of an oceanic island. Genetic data, using two different DNA methods, were obtained from more than 4,000 plants from the two major islands of the Juan Fernández Archipelago (Chile). Results show that some immigrant populations undergo major splitting events and harbor limited genetic diversity within each evolving line. In contrast, other immigrant populations establish and enlarge, but they never split, hence accumulating higher levels of genetic diversity.

Vegetation of Alejandro Selkirk Island (Isla Masafuera), Juan Fernández Archipelago, Chile

Abstract: We analyzed the vegetation of Alejandro Selkirk Island using the Zürich-Montpellier approach for taking relevés and subsequent classification by a multivariate approach and manual refinement. The resulting vegetation table demonstrates patterns of dominance and variation and the resulting vegetation units that were mapped onto aerial photographs to produce a vegetation map. Additional observations of several inaccessible sectors were gained from photos taken during a boat trip around the island. These results are combined in a colored map that shows the following vegetation units: (1) Dicksonia externa Tree Fern Community (upper montane forest); (2) Lophosoria quadripinnata Fern Community; (3) Fern-Grassland Mosaic; (4) Myrceugenia schulzei Forest (lower montane forest); (5) Anthoxanthum-Nassella Grassland; (6) Coastal Grassland with Juncus procerus; (7) Open Grassland (including Coastal Herb Communities); (8) Rocks, Erosional Zones; and (9) Cultivated and Escaped Plants Near the Settlement. In some cases these units consist of several communities together, often forming mosaic patterns where detailed resolution is not practicable. Unit 7, Open Grassland, has been applied to all areas with a plant cover below 40%, and unit 8, Rocks, Erosional Zones, indicates no or scarce vegetation (cover notably below 10%). Some plant assemblages cannot be shown on the map: (a) the small clusters of Drimys confertifolia; (b) the mostly linearly or patchily arranged Gunnera masafuerae community; (c) several plant assemblages found in the canyons; and (d) the Histiopteris incisa clusters between the tree ferns and tall ferns. We discuss composition of the observed plant communities, especially regarding alien impact, and compare our findings with those on Robinson Crusoe, the largest island of the archipelago.

Relaciones filogenéticas de Rhodolirium montanum Phil. y especies afines, basadas en secuencias nucleotídicas de la región ITS y análisis cariotípico

La taxonomia de los generos chilenos de Amaryllidaceae es confusa, persistiendo problemas taxonomicos tanto a nivel de generos como de especies. Actualmente existe controversia acerca de la correcta clasificacion de especies hasta ahora asignadas a Rhodophiala C.Presl. A traves del estudio de aspectos morfologicos, recientemente se ha sugerido la rehabilitacion del genero Rhodolirium Phil., donde Rhodolirium montanum Phil. es considerada como especie tipo. Esta especie ha sido denominada Rhodophiala rhodolirion (Baker) Traub en las clasificaciones tradicionales. Dado que los datos morfologicos han provisto informacion limitada y ambigua en la clasificacion de las Amarilidaceas chilenas, este trabajo evalua la pertinencia de formalizar la rehabilitacion del genero Rhodolirium y en particular de la especie Rhodolirium montanum, a traves de un analisis de morfologia cromosomica y de secuencias nucleotidicas de la region ITS de seis especies nativas de Amaryllidaceae. Los datos moleculares indican que las especies Rhodophiala bagnoldii, R. montana, R. splendens, R. phycelloides y R. ananuca forman un grupo monofiletico mas emparentado con Hippeastrum Herb. que con Rhodolirium, genero que se presenta como grupo hermano de Phycella en el analisis filogenetico. La separacion de Rhodolirium con respecto de Rhodophiala esta respaldada por diferencias en numero y morfologia cromosomica, presentando el primero un numero cromosomico de 2n = 16 y un indice de asimetria intracromosomica (Isc) de 0,46; mientras que el segundo posee 2n = 18 e Isc de 0,59-0,62. De esta manera, los resultados de los estudios cromosomicos y moleculares, junto a diferencias en exomorfologia, tales como forma del estigma, perigonio y paraperigonio, apoyan la validez del genero Rhodolirium Phil. y por ende de la especie Rhodolirium montanum Phil.

Desarrollo del gametofito y esporofito joven de Pteris chilensis Desv. (Pteridaceae-Pteridophyta)

El cultivo ex situ de Pteris chilensis Desv. a partir de esporas es presentado. La germinacion de las esporas ocurre a los 10-12 dias y el patron de germinacion es del tipo Vittaria. Un gametofito filamentoso de 3-4 celulas es obtenido a los 23-24 dias, logrando su desarrollo adulto entre los 60 a 95 dias. Este se caracteriza por ser cordiforme y con alas simetricas. Los arquegonios se forman antes que los anteridios. Finalmente, la primera fronde aparece a los 115 dias de sembradas las esporas. Las esporas se cultivaron en agar con medio nutritivo de Thompson, en camara de cultivo con un fotoperiodo de 12 horas luz (1.500 lux) y una temperatura promedio de 25°C

Biogeography and genetic consequences of anagenetic speciation of R haphithamnus venustus (Verbenaceae) in the Juan Fernández archipelago, Chile: insights from AFLP and SSR markers

The genus R haphithamnus (Verbenaceae) consists of two species, one in South America and another endemic to the Juan Fernandez archipelago, Chile. The genus represents an example of anagenetic speciation in which the island populations have diverged from their colonizing ancestors to the point where they are recognized as a distinct species. The island species R haphithamnus venustus differs from the continental R . spinosus primarily by floral traits associated with adaptation to hummingbird pollination. Two molecular markers, amplified fragment length polymorphisms (AFLPs) and microsatellites, were used to estimate divergence between the continental and insular species, and to compare diversity in the two species. The comparable or greater diversity in the insular species observed in some diversity indices of AFLPs would support the hypothesis that during the course of anagenetic speciation it has recovered from any reduction of genetic diversity associated with colonization of the archipelago. This pattern of comparable or higher diversity in insular species is seen with other instances of anagenetic speciation in the Juan Fernandez archipelago. By contrast, the lower genetic diversity in the insular R . venustus found in microsatellites is likely to be the result of a founder effect from the original colonization of the archipelago; prior molecular studies suggest recent colonization of the Juan Fernandez archipelago by R haphithamnus . The seeming non-concordance between the present results and the widely accepted biogeography of R haphithamnus inferred from other data is discussed and an explanation is presented.

Effect of bulb weight on the growth and flowering of Herbertia lahue subsp. lahue (Iridaceae)

P. Morales, F. Schiappacasse, P. Penailillo, and P. Yanez. 2009. Effect of bulb weight on growth and fl owering of Herbertia lahue subsp. lahue (Iridaceae). Cien. Inv. Agr. 36(2):259266. Bulb weight or size is one of the critical factors affecting the vegetative growth and fl owering of bulbous species. This study assessed the effect of bulb weight on the growth and fl owering of Herbertia lahue subsp. lahue. This bulbous species, commonly known as “lahue,” has the potential to be used as an ornamental plant. Lahue bulbs were collected during their dormant period from Tregualemu (Region del Maule), grouped by weight categories and planted in Talca in an unheated polyethylene greenhouse. Phenology data, fl owering characteristics and the number of newly formed bulbs were recorded for one season. Plants emerged 2-3 weeks after planting and fl owered during the spring, between 8 and 9 months after planting. During fruit set, the leaves began their senescence process and reached dormancy during the summer. Lahue behaved as a typical geophyte adapted to a seasonal climate such as the Mediterranean climate of Central Chile. Bulbs weighing 0.35 g or more were able to fl ower. However, bulbs greater than 0.75 g produced more and better quality fl owers. The average multiplication rate of the bulbs was 1-1.13 bulblets per planted bulb, regardless of the bulb weight; there was no correlation between multiplication rate and bulb weight. This study demonstrated that it is possible to grow lahue as a pot plant or garden plant and that the size of the bulb will determine if fl owering can be achieved.