Aarón Rodríguez

Assessing Genetic Diversity in Mexican Husk Tomato Species

Mexico is the center of diversity of the husk tomato (Physalis L., Solanaceae), which includes a number of commercially important edible and ornamental species. Taxonomic identification is presently based on morphological characteristics, but the presence of high inter- and intraspecific morphological variation makes this task difficult. Six ISSR primers were used on eight Mexican species of Physalis to determine their utility for interspecific taxonomic discrimination and to assess their potential for inferring interspecific relationships. The six ISSR primers amplified 101 bands, with 100% polymorphism across samples. The number of bands per primer varied from 10 to 21. All primers produced different fingerprint profiles for each species, confirming the ISSR value in taxonomic discrimination. Discrimination values based on Simpson’s diversity index varied from 0.48 to 0.58. Genetic interspecific similarity values ranged from 0.20 to 0.57, and intraspecific similarity values were highest for Physalis angulata (0.71), followed by Physalis philadelphica (0.63) and Physalis lagascae (0.55). The UPGMA analysis grouped accessions of the same species together and clustered together Physalis species of similar morphological traits. Thus, ISSR markers are useful in estimating genetic relationships in Physalis.

Areas of endemism of the North American species of Tigridieae (Iridaceae)

Abstract. The tribe Tigridieae (Iridoideae: Iridaceae) is a New World group with centres of diversity in Mexico and Andean South America. North America harbours 67 of the 172 species recognised within the tribe, 54 being endemic. Our aims were to identify areas of endemism of the North American Tigridieae using endemicity analysis (EA) and to infer their relationships using parsimony analysis of endemicity (PAE). A data matrix with 2769 geographical records of Tigridieae was analysed. The EA allowed to identify six consensus areas of endemism in Mexico. The PAE resulted in one cladogram with four clades and the following five biotic components: northern Mexico, western Mexico, central Mexico, southern Mexico and central–southern Mexico. The richness analysis of these areas of endemism indicated that the greatest concentration of species is located in central Mexico, with 14 species in one grid-cell. Grid-cells with 12 species each were identified in low western Mexico, high western Mexico, southern Mexico and central–southern Mexico. This last area is characterised by the greatest endemism, including nine species. The formation of the Transmexican Volcanic Belt seems to have been a key element to explain the diversification of North American Tigridieae.

Tigridia amatlanensis (Tigridieae: Iridaceae), a new species from Oaxaca, Mexico

Tigridia amatlanensis is described and illustrated as a new species from Mexico. It is recognized by its nodding flowers and its inner and outer tepals cirrhous and markedly dimorphic in length. It is most closely related toT. hallbergii subsp.hallbergii andT. meleagris. Other morphologically similar species areT. catarinensis andT. molseediana.ResumenSe describe e ilustra aTigridia amatlanensis como especie nueva que crece en México. Se reconoce por sus flores péndulas y sus tépalos cirrosos, los interiores mucho más pequeños que los exteriores. El taxón propuesto está relacionado conT. hallbergii subsp.hallbergii, T. meleagris. Morfológicamente, también es similar aT. catarinensis yT. molseediana.

Richness, geographic distribution patterns, and areas of endemism of selected angiosperm groups in Mexico: Species richness and endemism patterns in Mexico

Mexico is a megadiverse country. Presently, 22 126 species of angiosperms have been registered within its territory and 11 001 are considered to be endemic. However, their geographical distributions are far from homogeneous. In addition, Mexico is the center of diversification of several groups. Our analysis focused on such groups. The aims were to identify areas of species richness and endemism. A data matrix with 766 species and 25 579 geographical records was analyzed. It included Calochortus (Liliaceae); Bletia (Orchidaceae); Tigridieae (Iridaceae); Amaryllidaceae; Poliantheae, Echeandia (Asparagaceae); Crassulaceae; Hylocereus (Cactaceae); Solanum, Lycianthes and Physalinae (Solanaceae); Salvia section Membranaceae (Lamiaceae); and Cosmos and Dahlia (Asteraceae). Using Geographic Information Systems, we determined richness and distribution based on: (i) Mexican political divisions, (ii) biogeographical regions and provinces, (iii) a grid of 0.5 × 0.5° cells, and (iv) elevation. The areas of endemism were estimated using the endemicity analysis. The highest number of taxa and endemic plants were concentrated within the Transmexican Volcanic Belt in the Mexican Transition Zone. This mountain range has been recognized as a province on the basis of geologic, tectonic, geomorphologic, physiographic and biogeographic criteria. It is a 1000 km long volcanic arc that extends east to west through Central Mexico and is variably from 80 to 230 km wide, between 17°30′ to 20°25′N and 96°20′ to 105°20′W. Our results represent a local deviation from the global richness latitudinal gradient of angiosperm species.

Long distance dispersal in the assembly of floras: A review of progress and prospects in North America: Long distance dispersal of plants in North America

Here, we review progress and prospects to explicitly test for long distance dispersal biogeographic events. Long distance dispersal represents a “jump” across some kind of barrier, such as a topographic feature or a zone of unsuitable climate and may include repeated jumps, or stepping‐stone dispersals. Long distance dispersals were considered integral for explaining the organization of biodiversity at large and small scales by early biogeographers, such as Darwin and Wallace. Darwin, Wallace, and others envisioned that long distance dispersals were predictable events because the vectors for dispersal, such as animals, winds, and currents, behaved in non‐random ways. However, these early biogeographers found that dispersal was hard to observe, and, later, with the advent of the theory of Continental Drift, vicariance became regarded as a better scientific explanation for the arrangement of biodiversity, because it represented a falsifiable hypothesis. Thus, long distance dispersal was reduced to a nuisance parameter in biogeography; a random possibility that could never fully be ruled out in a scenario in which evidence supported vicariance. Today, there is strong interest to more fully integrate long distance dispersal into understanding the assembly and organization of biodiversity on earth. In this review, we discuss progress and prospects for explicitly testing long distance dispersal hypotheses including through uses of molecular, morphological, paleontological, and informatics methods. We focus on hypothesis testing of long distance dispersals involved in the assembly of the flora of North America, which is a robust preliminary study system on account of its extant and extinct biodiversity being well‐catalogued.

Polianthes quilae (Poliantheae, Agavaceae), a New and Endemic Species to Western Mexico

Abstract The floristic inventory of the Sierra de Quila Natural Reserve, in western Mexico, resulted in the discovery of Polianthes quilae (Polianthes subgen. Bravoa). The novelty is related to P. cernua and P. geminiflora var. clivicola but is distinguished by the erect lanceolate leaves, glauous inflorescence with 4–21 floral nodes, 0.9–2.1 cm long pedicels, tubular-ventricose and bicolorous perigone with ascending lobes, and filament insertion site 3–5 mm above ovary apex. Data on geographic distribution and ecology, phenology, and conservation status are presented. Lastly, a key to all species of Polianthes is provided. Resumen El inventario florístico del Área de Protección de la Flora y la Fauna Sierra de Quila, en el occidente de México, resultó en el descubrimiento de Polianthes quilae (Polianthes subgénero Bravoa). El nuevo taxón se relaciona con P. cernua y P. geminiflora var. clivicola pero se distingue por sus hojas erectas y lanceoladas, inflorescencias glaucas con 4–21 nudos florales, pedicelos de 0.9–2.1 cm de longitud, perigonio tubular-ventricoso y bicolor con los lóbulos ascendentes y por la inserción de los filamentos 3–5 mm por arriba del ápice del ovario. Se aportan datos sobre la distribución geográfica, hábitat, fenología y estado de conservación del taxón nuevo. También, se provee una clave para la identificación de las especies de Polianthes.

Echeandia novogaliciana and E. crudeniana (Anthericaceae): Two new species from western Mexico

Echeandia novogaliciana and E. crudeniana are described from western Mexico. Echeandia novogaliciana is known from three populations, one in the state of Nayarit and two in Zacatecas. Likewise, E. crudeniana is known from two populations in the municipality of Bahía de Banderas, Nayarit. For both species, illustrations are provided and morphological relationships with similar species are discussed.ResumenSe describen Echeandia novogaliciana y E. crudeniana del occidente de México. Echeandia novogaliciana se conoce de tres poblaciones en los estados de Nayarit y Zacatecas. Por su parte, en E. crudeniana se conoce de dos poblaciones en el municipio de Bahía de Banderas, Nayarit. Ambas especies se ilustran y se discute su relación con especies morfológicamente afines.