Gonzalez Astorga Jorge Arturo

• Doctor of Philosophy
• Institute of Ecology INECOL

Dioon angustifolium was considered within D. edule. Recent morphometric and allozyme studies on D. edule have shown that D. angustifolium has originated from geographic isolation and is therefore considered to be a separate species. This cycad is endemic to north-eastern Mexico and is known only from three populations in the Sierra Madre Oriental m...

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To understand the evolutionary history of species, it is necessary to know the mechanisms for reproductive isolation, divergence-time between populations, and the relative action of the evolutionary forces (e.g., mutation, genetic drift, gene flow) within and between populations of the same, or closely related species. Although Canthon is one of th...

Plant invasions have a huge impact on the health of ecosystems and human well-being. The invasion risk varies with the introduction pathway, the propagule pressure, and the genetic diversity of the founding population. We performed a systematic review and meta-analysis of 30 studies reporting the genetic diversity of 31 plant species in their invas...

RESUMEN Conocer los procesos que determinan la adecuación de las poblaciones es importante para dilucidar las probabilidades de permanencia y/o extinción de las especies, particularmente, en especies endémicas sujetas al efecto de la fragmentación, para las que son urgentes estrategias de conservación. En esta investigación se utilizaron modelos ma...

Oenothera drummondii Hook. (Onagraceae) has life-history traits that make it an invasive species. Native populations are distributed along the coastal dunes from North Carolina in the United States to Tabasco in the Gulf of Mexico. It has been reported as an invasive species in Spain, Israel, and China, where this species can successfully colonize...

We analysed the genetic divergence and morphology of the aedeagus (i.e. phallobase and parameres) in Canthon cyanellus at different geographical levels. The results from both approaches were compared with the current taxonomic assignment of the C. cyanellus complex, which includes three subspecies. We found a high variation in all the morphological...

We analysed the genetic divergence and morphology of the aedeagus (i.e. phallobase and parameres) in Canthon cyanellus at different geographical levels. The results from both approaches were compared with the current taxonomic assignment of the C. cyanellus complex, which includes three subspecies. We found a high variation in all the morphological...

Evidence suggests that past climatic fluctuations affected speciation of extant cycads. However, empirical genetic and morphological evidence explaining patterns and processes of species diversification are scarce. There are some explanations for the origin and evolution of the genus Ceratozamia, but with inconclusive results. To elucidate the evol...

Demographic models based on projection matrices can infer the effect of disturbance on natural cycad populations by human activities. However, owing to the longevity of plants, it is difficult to determine long-term population dynamics. Fortunately, today, several population studies have allowed us to determine the overall effects of disturbance on...

Abstract Demographic models based on projection matrices can infer the effect of disturbance on natural cycad populations by human activities. However, owing to the longevity of plants, it is difficult to determine long-term population dynamics. Fortunately, today, several population studies have allowed us to determine the overall effects of distu...

Canthon cyanellus is a roller dung beetle with a wide distribution range in the tropical forests of the New World. In Mexico, it inhabits the Pacific and the Gulf coasts, the Yucatan Peninsula and the south mainly in the State of Chiapas. This species shows a wide geographical variation in cuticle color, which has been used as defining trait for su...

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...

The Cycadales contain 11 nonproblematic genera and approximately 331 species where, in a number of cases, delimitation and circumscription is not so clear. Ceratozamia, the most diverse cycad genus in Mexico, clearly illustrates this situation because a large percentage (close to 70%) of the 28 currently valid species in the genus was recently desc...

Premise of the study: Dioon (Zamiaceae) is an endangered North American cycad genus of evolutionary and ornamental value. We designed and validated a set of microsatellite markers from D. edule that can be used for population-level and conservation studies, and that transferred successfully to D. angustifolium, D. spinulosum, and D. holmgrenii. M...

We have investigated the phylogeographic structure and demographic history of Zamia paucijuga, based on 120 ITS2 and 117 psbK/I sequences from 13 populations distributed along the entire distribution range of the species. We have detected 15 ITS2 and four psbK/I haplotypes, for a total of 19. The genetic diversity estimated for psbK/I was relativel...

Dentro de los grupos actuales de espermatofitas, plantas con semilla, las cícadas cuentan con el registro fósil más antiguo. A pesar de ello, su estatus como “fósiles vivientes” ha sido puesto en entredicho recientemente con base en resultados de estudios filogenéticos moleculares. El grupo presenta apomorfías morfológicas vegetativas y posiblement...

Comparisons of genetic diversity and population genetic structure among different life history stages provide important information on the effect of the different forces and micro-evolutionary processes that mould diversity and genetic structure after fragmentation. Here we assessed genetic diversity and population genetic structure using 32 allozy...

An understanding of how genetic variation is distributed locally is not only vital to the diagnosis of the conservational status of a species, but also to prioritize actions of sustainable management. We compared the fine-scale spatial genetic structure (SGS) of two Mexican cycads, Dioon caputoi and Dioon merolae, which differ in aspects such as di...

With the recent proposal of matK and rbcL as core plant DNA barcoding regions by the Consortium for the Barcoding of Life Plant Working Group, the construction of reference libraries in the botanical DNA barcoding initiative has entered a new phase. However, in a recent DNA barcoding study in the three Mexican genera of the gymnosperm order Cycadal...

The genus Zamia in Megamexico includes 22 described species and one entity in the species dubium category (Z. verschaffeltii). During the last 2 decades, the genus Zamia has received attention in regional floristic treatments and, outstandingly, in a specialized monograph. Besides, some species in the genus have been the focus of several recent cyt...

The genus Zamia in Megamexico includes 22 described species and one entity in the species dubium category (Z. verschaffeltii). During the last 2 decades, the genus Zamia has received attention in regional floristic treatments and, outstandingly, in a specialized monograph. Besides, some species in the genus have been the focus of several recent cyt...

Allozyme diversity and population genetic structure studies were conducted in populations of two Mexican cycad species occurring in adjacent and closely related biogeographic regions. We evaluated if rarity traits in Dioon caputoi, a micro-endemic species, and Dioon merolae, a regional endemic with a wider distribution, influence levels of genetic...

A DNA barcoding study was conducted to determine the optimal combination of loci needed for successful species-level molecular identification in three extant cycad genera—Ceratozamia, Dioon, and Zamia—that occur in Mexico. Based on conclusions of a previous multigene study in representative species of all genera in the Cycadales, we tested the DNA...

The diversity and genetic structure of seven populations of Microcycas calocoma (Miq.) A. DC, were analyzed by gel electrophoresis using 19 allozymes. The mean number of alleles per locus (A) was 1.49 and the percentage of polymorphic loci was relatively high (P = 48.09). The mean observed (Ho) and expected heterozygosity (He) were 0.20 and 0.17, r...

A few generalizations have been made about the amount of genetic diversity and life-history traits in plants, and a number of studies have reported contrasting results, indicating that these generalizations are not necessarily reliable. Six Govenia species belonging to three groups characterized by different pollinator attraction strategies were st...

The new species Dioon stevensonii, from the Rio Balsas basin spanning the states of Michoacan and Guerrero, Mexico, is described and illustrated. The description of this species implies a recircumscription of the populations of Dioon that constitute the previously characterised D. tomasellii, which also includes populations located in Durango, Naya...

The distribution of genetic diversity and structure for three populations of Dioon edule Lindley (Zamiaceae) at Monte Oscuro (MO), El Farallón (EF) and Rancho del Niño (RN) in Veracruz, Mexico was studied using 20 allozyme loci, considering four life history classes: seeds, seedlings, juveniles and adults. The MO population is genetically less dive...

The diversity and genetic structure of the cycad Dioon sonorense (De Luca, Sabato & Vázq. Torres) Chemnick, T.J. Greg. & S. Salas-Mor. were evaluated from the four known populations in tropical dry forests of Sonora, Mexico. The estimates of genetic diversity in the 19 loci analysed were: mean number of alleles per locus (A = 2.0), percentage of po...

Dioon caputoi is a long-lived cycad known from only four populations that range in size from 50 to 120, mostly adult individuals. Dioon caputoi has the most narrow geographical range of all Dioon spp. (less than 10 km), existing completely within the boundaries of the Tehuacán–Cuicatlán Biosphere Reserve, Mexico. Negative inbreeding values were fou...

We have estimated levels of genetic diversity and partitioning in the Mexican endemic cycad species Dioon sonorense, Dioon tomasellii, and Dioon holmgrenii, whose populations are exclusively distributed along the Pacific seaboard. For the three species, the patterns of variation at 19 allozyme loci in a total of 11 populations were evaluated. The a...

The demographic dynamics of three populations of Dioon edule Lindl. (Zamiaceae) were studied in a fragmented landscape using projection matrix modelling. Compared with other plant species, D. edule behaves like a tree life-form species. Density and spatial distribution patterns varied among populations according to models for animal-dispersed tree...

Ceratozamia chimalapensis sp. nov. is described and illustrated. It is related to C. mirandae Vovides, Pérez-Farrera & Iglesias from Chiapas, but differs in trunk and peduncle size as well as in diameter of both megastrobili and microstrobili. Petiole, megasporophyll and indument colour also differ from that of C. mirandae. Ceratozamia chimalapensi...

The new species Ceratozamia vovidesii from a Pleistocene floristic refuge in southern Mexico is described and illustrated. It show an affinity with C. matudae Lundell and C. mirandae Vovides, Pérez-Farrera & Iglesias from Chiapas, but it differs from them in leaf, male and female cones, and trunk morphology.

The genetic diversity and structure of four populations of the cycad Zamia loddigesii were studied throughout its range in Mexico. Allozyme electrophoresis of 15 loci was conducted. The mean number of alleles per locus was 1.80 ± 0.09, the percentage of polymorphic loci was 66.6 ± 5.4, and the expected heterozygosity was 0.266 ± 0.02. The results i...

The cycad Ceratozamia mirandae is endemic to Chiapas, Mexico. Demographic studies were made in two of its populations in the Sepultura Biosphere Reserve under different conservation conditions; in the nucleus zone “Tres Picos” (conserved) and buffer zone “La Sombra” (disturbed and under management). Spatial distribution of C. mirandae was aggregate...

Genetic structure and variability were examined in the only three extant populations of the narrow-endemic tree Antirhea aromatica (Rubiaceae, Guettardeae), an endangered species of the tropical forest of eastern Mexico. Patterns of genetic diversity within and among populations for adult plants and seedlings were obtained. Allozyme electrophoresis...

Dioon edule Lindl. (Zamiaceae) is a cycad endemic to Mexico, that occurs as one species D. edule and the geographical variety D. edule var. angustifolium (Miq.) Miq. Dioon edule has a north to south distribution in eastern Mexico. In this study, we analysed 14 allozymic loci in eight populations of D. edule from its total distribution range by samp...

The relationship in geographical distribution and morphological variation of leaflet width and length (diagnostic trait), between and within populations of Dioon edule Lindl., has been investigated throughout its known range in eastern Mexico (from the states of Nuevo León to Veracruz, north to south, respectively). A total of 1832 leaflets were me...

subsequent migrations up valleys and canyons and towards the northwest (D. tomase//ii) along the Mexican Pacific with a morphologically distinct specl'es (D. sonorense) in the extreme northwestern limit. Like-wise for Dioon edu/e where the genetic variation was found to be maximum in the south-eastern limit of its range and minimum in populations t...

The monoecious, animal-pollinated shrub Brongniartia vazquezii is an endemic and endangered species of the tropical dry forests of Central Mexico. Deforestation of the tropical dry forest has fragmented the habitat and resulted in the isolation of the only four extant populations of B. vazquezii. In this study, we assessed the genetic consequences...

This study tests whether variability in a life history trait such as emergence time has ecological and evolutionary significance in seasonal environments due to their relationship with fitness components. The population dynamics of nine different cohorts of seedlings emergence were analyzed in a natural population of the annual herb Tagetes micrant...

Stabilizing selection, which favors intermediate phenotypes, is frequently invoked as the selective force maintaining a population's status quo. Two main alternative reasons for stabilizing selection on a quantitative trait are possible: (1) intermediate trait values can be favored through the causal effect of the trait on fitness (direct stabilizi...