scholarly journals Origen, variación y tendencias evolutivas del Henequén (Agave fourcroydes Lem.)

2017 ◽  
pp. 109
Author(s):  
Patricia Colunga-García Marín
Keyword(s):  
Deciduous Forest ◽  
Sister Group ◽  
Reproductive Capacity ◽  
Tropical Deciduous Forest ◽  
Wild Populations ◽  
Origin And Evolution ◽  
Research Perspectives ◽  
Agave Fourcroydes ◽  
Cultivated Populations ◽  
Maya People

Henequen was domesticated by the Maya people, from A. angustifolia, since pre-Hispanic times. It is one of the most important natural hard fibers worldwide because of its good quality and adaptation to ecologically restricted agrohabitats. This cultivar has maintained great economic and cultural value in the state of Yucatan. Ethnobotanical, morphological, and isozyme evidence were compiled to discuss the origin and evolution of henequen by human selection, the germplasm diversity available in the cultivated populations and that of the wild populations from which it could have arisen. Results suggested the occurrence of a drastic erosion of the genetic diversity maintained by the Maya, as a consequence of its cultivation under large plantations established at the beginning of this century for the cordage industry. At present, only three varities are cultivated: Sak ki (SK), Yaax ki (YK) and Kitam ki (KK), these last two in very small populations. SK and YK differ from wild populations in four syndromes of domestication: gigantism, greater fibrosity, less thorniness, and less reproductive capacity. KK is very similar to the wild types. Isozyme analysis indicated that wild populations have relatively high levels of variation, whereas all individuals of each henequen variety were identical. A parsimony analysis indicated two lineages: that of SK and YK, cultivated cordage plants selected for stronger and longer fibers, whose sister group is the tropical deciduous forest ecotype (SF); and that of ali other wild populations, which also included KK, the cultivated textile plants selected for finer fibers, and nearly extint in Yucatan. These  results support the hypothesis of the yucatecan origin of SK and YK from the SF ecotype, as well as the recent introduction of KK. Methodology used is discussed as well as research perspectives in this theme.

scholarly journals Identification of medicinal plant Schisandra chinensis using a potential DNA barcode ITS2

2013 ◽  
Vol 82 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Xian-kuan Li ◽  
Bing Wang ◽  
Rong-chun Han ◽  
Yan-chao Zheng ◽  
Hai-bo Yin Yin ◽  
...  
Keyword(s):  
Dna Barcode ◽  
Population Level ◽  
Species Level ◽  
Its2 Region ◽  
Schisandra Chinensis ◽  
Success Rates ◽  
Wild Populations ◽  
Efficient Tool ◽  
Different Populations ◽  
Cultivated Populations

To test whether the internal transcribed spacer 2 (ITS2) region is an effective marker for using in authenticating of the <em>Schisandra chinensis</em> at the species and population levels, separately. And the results showed that the wild populations had higher percentage of individuals that had substitution of C→A at site 86-bp than the cultivated populations. At sites 10-bp, 37-bp, 42-bp and 235-bp, these bases of the <em>Schisandra sphenanthera</em> samples differed from that of <em>S. chinensis</em>. Two species showed higher levels of inter-specific divergence than intra-specific divergence within ITS2 sequences. However, 24 populations did not demonstrate much difference as inter-specific and intra-specific divergences were concerned. Both <em>S. chinensis</em> and <em>S. sphenanthera</em> showed monophyly at species level, yet the samples of different populations shown polyphyly at population level. ITS2 performed well when using BLAST1 method. ITS2 obtained 100% identification success rates at the species level for <em>S. chinensis</em>, with no ambiguous identification at the genus level for ITS2 alone. The ITS2 region could be used to identify <em>S. chinensis</em> and <em>S. sphenanthera</em> in the “Chinese Pharmacopoeia”. And it could also correctly distinguish 100% of species and 100% of genera from the 193 sequences of <em>S. chinensis</em>. Hence, the ITS2 is a powerful and efficient tool for species identification of <em>S. chinensis</em>.

Paleoecological and archaeological implications of a Late Pleistocene/Early Holocene record of vegetation and climate from the Pacific coastal plain of Panama

2003 ◽  
Vol 59 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Dolores R. Piperno ◽  
John G. Jones
Keyword(s):  
Tropical Forest ◽  
Late Pleistocene ◽  
Coastal Plain ◽  
Deciduous Forest ◽  
Early Holocene ◽  
Tropical Deciduous Forest ◽  
Human Occupation ◽  
Core Sediment ◽  
The Pacific ◽  
Holocene Record

AbstractA phytolith record from Monte Oscuro, a crater lake located 10 m above sea level on the Pacific coastal plain of Panama, shows that during the Late Pleistocene the lake bed was dry and savanna-like vegetation expanded at the expense of tropical deciduous forest, the modern potential vegetation. A significant reduction of precipitation below current levels was almost certainly required to effect the changes observed. Core sediment characteristics indicate that permanent inundation of the Monte Oscuro basin with water occurred at about 10,500 14C yr B.P. Pollen and phytolith records show that deciduous tropical forest expanded into the lake’s watershed during the early Holocene. Significant burning of the vegetation and increases of weedy plants at ca. 7500 to 7000 14C yr B.P. indicate disturbance, which most likely resulted from early human occupation of the seasonal tropical forest near Monte Oscuro and the development of slash-and-burn methods of cultivation.

Wood Specific Gravity in Species from Two Tropical Forests in Mexico

IAWA Journal ◽  
1987 ◽  
Vol 8 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Josefina Barajas-Morales
Keyword(s):  
Specific Gravity ◽  
Tropical Forests ◽  
Tropical Rainforest ◽  
Deciduous Forest ◽  
Woody Species ◽  
T Test ◽  
Tropical Deciduous Forest ◽  
Wood Specific Gravity ◽  
Dry Deciduous Forest

The specific gravity of 220 woody species, half of them from a tropical rainforest, half from a tropical deciduous forest was measured. The two groups were compared using a Student t-test. The results show highly significant differences in specific gravity between the species from the two areas: woods from the dry deciduous forest tend to be much heavier than those from the rainforest.

Successional Change and Resilience of a Very Dry Tropical Deciduous Forest Following Shifting Agriculture

Biotropica ◽  
2008 ◽  
Vol 40 (4) ◽  
pp. 422-431 ◽  
Author(s):  
Edwin Lebrija-Trejos ◽  
Frans Bongers ◽  
Eduardo A. Pérez-García ◽  
Jorge A. Meave
Keyword(s):  
Deciduous Forest ◽  
Tropical Deciduous Forest ◽  
Shifting Agriculture ◽  
Successional Change

Dry Season Den Use by Pygmy Spotted Skunk (Spilogale pygmaea) in a Tropical Deciduous Forest of Mexico

Biotropica ◽  
2009 ◽  
Vol 41 (3) ◽  
pp. 347-353 ◽  
Author(s):  
Lisette Cantú-Salazar ◽  
Mircea G. Hidalgo-Mihart ◽  
Carlos A. López-González ◽  
Alberto González-Romero
Keyword(s):  
Deciduous Forest ◽  
Dry Season ◽  
Tropical Deciduous Forest ◽  
Den Use

scholarly journals The genome of the blind soil-dwelling and ancestrally wingless dipluran Campodea augens, a key reference hexapod for studying the emergence of insect innovations

2019 ◽  
Author(s):  
Mosè Manni ◽  
Felipe A. Simao ◽  
Hugh M. Robertson ◽  
Marco A. Gabaglio ◽  
Robert M. Waterhouse ◽  
...  
Keyword(s):  
Draft Genome ◽  
Gene Families ◽  
Sister Group ◽  
Sensu Stricto ◽  
Comparative Genomic ◽  
Gene Repertoire ◽  
Animal Group ◽  
Origin And Evolution ◽  
Genomic Analyses ◽  
Metabolism Gene

AbstractThe dipluran two-pronged bristletail Campodea augens is a blind ancestrally wingless hexapod with the remarkable capacity to regenerate lost body appendages such as its long antennae. As sister group to Insecta (sensu stricto), Diplura are key to understanding the early evolution of hexapods and the origin and evolution of insects. Here we report the 1.2-Gbp draft genome of C. augens and results from comparative genomic analyses with other arthropods. In C. augens we uncovered the largest chemosensory gene repertoire of ionotropic receptors in the animal kingdom, a massive expansion which might compensate for the loss of vision. We found a paucity of photoreceptor genes mirroring at the genomic level the secondary loss of an ancestral external photoreceptor organ. Expansions of detoxification and carbohydrate metabolism gene families might reflect adaptations for foraging behaviour, and duplicated apoptotic genes might underlie its high regenerative potential.The C. augens genome represents one of the key references for studying the emergence of genomic innovations in insects, the most diverse animal group, and opens up novel opportunities to study the under-explored biology of diplurans.

scholarly journals Inventario florístico del Cerro El Cebú y zonas adyacentes en la Reserva de la Biosfera El Triunfo (Polígono V), Chiapas, México

2017 ◽  
pp. 21
Author(s):  
Jorge Martínez-Meléndez ◽  
Miguel Ángel Pérez-Farrera ◽  
Oscar Farrera-Sarmiento
Keyword(s):  
Plant Communities ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Deciduous Forest ◽  
Cloud Forest ◽  
Biosphere Reserve ◽  
Red List ◽  
Tropical Deciduous Forest ◽  
Oak Forest

A total of 502 species that belong to 115 families and 301 genera were recorded for Mt. El Cebu and adjacent zones in Polygon V of the El Triunfo Biosphere Reserve. The most speciose families were Orchiclaceae, Fabaceae, Asteraceae, Bromeliaceae and polypodiaceae with 58, 29, 28, 17, and 17 species, respectively. Six plant communities were recognized in the area, among which the cloud forest was the most diverse with 234 species, followed by pine-oak fore st with 150 species, and the tropical rain forest with 127. The oak forest and the tropical deciduous forest were less diverse, with 71 and 39 species, respectively. Only 13 species are included in the Mexican red list of endangered taxa.

scholarly journals Componentes fenológicos del sistema de cruzamiento monoico de Cnidoscolus spinosus (Euphorbiaceae) en Jalisco

2017 ◽  
pp. 1
Author(s):  
Stephen H. Bullock
Keyword(s):  
Deciduous Forest ◽  
Tropical Deciduous Forest ◽  
Western Mexico ◽  
Mature Period ◽  
Individual Trees ◽  
Female Flowers

A hierarchy of phenological features defines the opportunities for breeding in a population of Cnidoscolus spinosus in a tropical deciduous forest in western Mexico. On any one tree, inflorescences develop in rough synchrony and all present flowers of both sexes. Only female flowers develop at the lowest ranks of ramification but only males develop later. Overlap of the mature period of flowers of both sexes is uncommon on one inflorescence of between inflorescences : individual trees are functionally female or male at any moment. lnter-tree synchrony may thus reduce successful breeding. Asynchrony is achieved in part by differences in the onset of flowering, but also by variance in the lenght of individual flowering cycles. The occurrence of two or three cycles per tree during one season for the population increases its breeding opportunities.

scholarly journals Análisis de crecimiento de tres especies de Caesalpinia (Leguminosae) de la selva baja caducifolia de Chamela, Jalisco

2017 ◽  
pp. 5
Author(s):  
Emmanuel Rincón ◽  
Pilar Huante ◽  
Mariana Álvarez-Añorve
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Deciduous Forest ◽  
Growth Period ◽  
Growth Patterns ◽  
Tropical Deciduous Forest ◽  
Total Biomass ◽  
Allocation Pattern ◽  
Location Patterns ◽  
Net Assimilation

The objective of this study is to assess the biomass allocation pattern s and growth characteristics of three species of Caesalpinia (Leguminosae) from the highly diverse and seasonal Chamela tropical deciduous forest , where the plant growth period is restricted to the rainy season. The studied species, although they are phylogenetically related, presented different biomass al location patterns and RGR during growth, in order to carry out a differential exploitation of resources and to promote their coexistence. There were differences in relative growth rate (RGR), root to shoot ratio (R/ S), net assimilation rate (E), biomass allocation patterns and total biomass and leaf area attained among the studied species. Caesalpinia eriostachys and C. platyloba showed similar growth patterns between them but contrasting with those of C. sclerocarpa. This suggests a temporal uncuopling of their maximum resource demand. RGR was determined to a greater extent by parameters related with E than by parameters related with the specific leaf area (SLA).

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