scholarly journals Reproductive biology of the threatened species Furcraea parmentieri (Aspargaceae)

2017 ◽  
Vol 95 (3) ◽  
pp. 409
Author(s):  
Maria Albarrán ◽  
Arturo Silva-Montellano ◽  
Teresa Valverde
Keyword(s):  
Threatened Species ◽  
Fruit Set ◽  
Volcanic Belt ◽  
Reproductive Traits ◽  
Reproductive Phenology ◽  
Pollinator Limitation ◽  
Nectar Production ◽  
Mexican Volcanic Belt ◽  
Genetic Diversity And Structure ◽  
Study Sites

<p><strong>Background:</strong> Reproductive traits are features of a species’ biology that may determine its rarity, as they affect its genetic diversity and structure, as well as its population dynamics.</p><p><strong>Study species</strong>: The rare and threatened species <em>Furcraea parmentieri</em>, whose distribution is limited to the Trans-Mexican volcanic belt. </p><p><strong>Questions:</strong> How is the reproductive phenology of <em>F. parmentieri</em>? Does flower morphology vary between individuals? Does it produce nectar? Which animals visit its flowers? Is it self-compatible? Do the seeds originated via different pollination treatments show differences in their germinability?</p><p><strong>Study sites and dates: </strong>We studied the <em>F. parmentieri</em> from 2007 to 2008, at El Xitle volcano (altitude: 2800 – 3100 m; pine-oak forest), in the south of Mexico City.<strong></strong></p><p><strong>Methods:</strong> Reproductive phenology was recorded through fortnightly visits to the study site. Flowers were collected, flower visitors were recorded and nectar production was measured. An experiment was done which included four treatments: autonomous pollination, geitonogamy, cross pollination, and a control. We measured seed set, fruit set and seed germination in each treatment.</p><p><strong>Results:</strong> Inflorescences started in January and flowering finished in May. Fruit maturation took from May to November. Nectar production was negligible. Flowers were visited by hawkmoths and hummingbirds. Fruit set was very low (ca. 5 %) and we observed self-incompatibility.  <strong>  </strong></p><strong>Conclusions:</strong> <em>Fucraeae</em> <em>parmentieri </em>presents a low fruit set due to pollinator limitation. However the population seems to be thriving. The main threat faced by this species is the high land-use change rate along its distribution range, as well as climate change.

scholarly journals Rapid and recent allopatric speciation in firs from central Mexico: evidence for reinforcement?

2021 ◽  
Author(s):  
Gustavo Giles-Pérez ◽  
Erika Aguirre-Planter ◽  
Luis Eguiarte ◽  
Juan Jaramillo-Correa
Keyword(s):  
Reproductive Isolation ◽  
Volcanic Belt ◽  
Secondary Contact ◽  
Reproductive Phenology ◽  
Central Mexico ◽  
Sky Islands ◽  
Hybrid Fitness ◽  
Mexican Volcanic Belt ◽  
History Of ◽  
Self Fertilization

Secondary contact of species that have evolved partial reproductive isolation in allopatry may result in several outcomes, which range from rampant hybridization to barrier reinforcement. Reinforcement arises from reduced hybrid fitness, which promotes assortative mating and hence speciation. In plants, self-fertilization and disjunctions in reproductive-phenology are often invoked as evidence of reinforcement. However, local adaptation and pleiotropic effects during colonization can also lead to reproductive isolation without reinforcement. We explored these possibilities in a fir species complex (Abies flinckii - A. religiosa) distributed in ‘sky-islands’ along the Trans-Mexican Volcanic Belt (TMVB), in central Mexico. Despite co-occurring in two independent sympatric regions (west and center), these two taxa seem to rarely interbreed because of disjunct reproductive phenologies. We genotyped 1,147 SNPs, generated by GBS across 23 populations, and compared multiple demographic scenarios, built based on the geological history of the TMVB. The best-fitting model suggested a recent species split (for a conifer), dating back to ~1.2 Ma, together with early asymmetric gene flow (mostly from A. flinckii into A. religiosa), limited to the central sympatric region. Coupled with the lack of support for colonization models, the summary statistics (f, Hobs, FST, θπ, etc.) and historical demographic inferences made herein point to a rapid speciation with an early development of reinforcement, as a putative mechanism for avoiding hybridization. The role of reinforcement should be thus further explored in the (sub)tropics, as likely explanation for how species diversity is generated and maintained.

scholarly journals Gynomonoecy in a mycoheterotrophic orchid Eulophia zollingeri with autonomous selfing hermaphroditic flowers and putatively outcrossing female flowers

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10272
Author(s):  
Kenji Suetsugu
Keyword(s):  
Fruit Set ◽  
Floral Morphology ◽  
Extreme Case ◽  
Reproductive Traits ◽  
Mixed Mating ◽  
Pollinator Limitation ◽  
Orchid Species ◽  
System A ◽  
Floral Visitors ◽  
Female Flowers

Most orchid species exhibit an extreme case of hermaphroditism, owing to the fusion of male and female organs into a gynostemium. Exceptions to this rule have only been reported from the subtribes Catasetinae and Satyriinae. Here, I report an additional orchidaceous example whose flowers are not always hermaphroditic. In several Japanese populations of Eulophia zollingeri (Rchb.f.) J.J.Sm, a widespread Asian and Oceanian orchid, some flowers possess both the anther (i.e., anther cap and pollinaria) and stigma, whereas others possess only the stigma. Therefore, pollination experiments, an investigation of floral morphology and observations of floral visitors were conducted to understand the reproductive biology of E. zollingeri in Miyazaki Prefecture, Japan. It was confirmed that E. zollingeri studied here possesses a gynomonoecious reproductive system, a sexual system in which a single plant has both female flowers and hermaphroditic flowers. In addition, hermaphroditic flowers often possess an effective self-pollination system while female flowers could avoid autogamy but suffered from severe pollinator limitation, due to a lack of agamospermy and low insect-mediated pollination. The present study represents the first documented example of gynomonoecy within Orchidaceae. Gynomonoecy in E. zollingeri may be maintained by the tradeoff in reproductive traits between female flowers (with low fruit set but potential outcrossing benefits) and hermaphroditic flowers (with high fruit set but inbreeding depression in selfed offspring). This mixed mating is probably important in mycoheterotrophic E. zollingeri because it occurs in shaded forest understorey with a paucity of pollinators.

scholarly journals Genetic diversity and structure of two endangered mole salamander species of the Trans-Mexican Volcanic Belt

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 237-248 ◽  
Author(s):  
Octavio Monroy-Vilchis ◽  
Rosa-Laura Heredia-Bobadilla ◽  
Martha M. Zarco-González ◽  
Víctor Ávila-Akerberg ◽  
Armando Sunny
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Population Size ◽  
Effective Population Size ◽  
Volcanic Belt ◽  
Population Declines ◽  
Effective Population ◽  
Mexican Volcanic Belt ◽  
Genetic Diversity And Structure ◽  
Trans Mexican Volcanic Belt

The most important factor leading to amphibian population declines and extinctions is habitat degradation and destruction. To help prevent further extinctions, studies are needed to make appropriate conservation decisions in small and fragmented populations. The goal of this study was to provide data from the population genetics of two micro-endemic mole salamanders from the Trans-Mexican Volcanic Belt. Nine microsatellite markers were used to study the population genetics of 152 individuals from two Ambystoma species. We sampled 38 individuals in two localities for A. altamirani and A. rivualre. We found medium to high levels of genetic diversity expressed as heterozygosity in the populations. However, all the populations presented few alleles per locus and genotypes. We found strong genetic structure between populations for each species. Effective population size was small but similar to that of the studies from other mole salamanders with restricted distributions or with recently fragmented habitats. Despite the medium to high levels of genetic diversity expressed as heterozygosity, we found few alleles, evidence of a genetic bottleneck and that the effective population size is small in all populations. Therefore, this study is important to propose better management plans and conservation efforts for these species.

scholarly journals Geochemical Evidence for Slab Melting in the Trans-Mexican Volcanic Belt

2006 ◽  
Vol 48 (3) ◽  
pp. 537-562 ◽  
Author(s):  
A. Gomez-Tuena ◽  
C. H. Langmuir ◽  
S. L. Goldstein ◽  
S. M. Straub ◽  
F. Ortega-Gutierrez
Keyword(s):  
Volcanic Belt ◽  
Slab Melting ◽  
Geochemical Evidence ◽  
Mexican Volcanic Belt ◽  
Trans Mexican Volcanic Belt

scholarly journals Evidence for geomagnetic excursions recorded in Brunhes and Matuyama Chron lavas from the trans-Mexican volcanic belt

2013 ◽  
Vol 118 (6) ◽  
pp. 2648-2669 ◽  
Author(s):  
Daniel M. Michalk ◽  
Harald N. Böhnel ◽  
Norbert R. Nowaczyk ◽  
Gerardo J. Aguírre-Diaz ◽  
Margarita López-Martínez ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Matuyama Chron ◽  
Mexican Volcanic Belt ◽  
Trans Mexican Volcanic Belt

Volcano-sedimentary processes at Las Derrumbadas rhyolitic twin domes, Serdán-Oriental basin, Eastern Trans-Mexican Volcanic Belt

2021 ◽  
pp. SP520-2021-144
Author(s):  
Marie-Noëlle Guilbaud ◽  
Corentin Chédeville ◽  
Ángel Nahir Molina-Guadarrama ◽  
Julio Cesar Pineda-Serrano ◽  
Claus Siebe
Keyword(s):  
Volcanic Belt ◽  
Debris Avalanche ◽  
Density Currents ◽  
Content Type ◽  
Mexican Volcanic Belt ◽  
Wide Range ◽  
Eruptive Episode ◽  
Basin Floor ◽  
Supplementary Material ◽  
Trans Mexican Volcanic Belt

AbstractThe eruption of the ∼10 km3 rhyolitic Las Derrumbadas twin domes about 2000 yrs ago has generated a wide range of volcano-sedimentary deposits in the Serdán-Oriental lacustrine basin, Trans-Mexican Volcanic Belt. Some of these deposits have been quarried, creating excellent exposures. In this paper we describe the domes and related products and interpret their mode of formation, reconstructing the main phases of the eruption as well as syn-and-post eruptive erosional processes. After an initial phreatomagmatic phase that built a tuff ring, the domes grew as an upheaved plug lifting a thick sedimentary pile from the basin floor. During uplift, the domes collapsed repeatedly to form a first-generation of hetero-lithologic hummocky debris avalanche deposits. Subsequent dome growth produced a thick talus and pyroclastic density currents. Later, the hydrothermally-altered over-steepened dome peaks fell to generate 2nd generation, mono-lithologic avalanches. Subsequently, small domes grew in the collapse scars. From the end of the main eruptive episode onwards, heavy rains remobilized parts of the dome carapaces and talus, depositing lahar aprons. Las Derrumbadas domes are still an important source of sediments in the basin, and ongoing mass-wasting processes are associated with hazards that should be assessed, given their potential impact on nearby populations.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5752296

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