Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Background: Aporocactus is an epiphytic or saxicolous genus that is endemic to Mexico and has a distribution restricted to cloud forests and pine-oak forests. As with many cacti, Aporocactus presents taxonomic conflicts, especially regarding species delimitation, since five species in this genus have been described and accepted by some authors, while others accept only two species. Questions: How many species comprise Aporocactus? What are their relationships? Do these species show differences in their climatic preferences? Studied species: The five putative species in Aporocactus were investigated. Study site and dates: This study was conducted in 2015 and 2016. The collection sites were in Hidalgo, Puebla, Querétaro, Veracruz, and Oaxaca states, Mexico. Methods: In this study, phylogenetic analyses were performed using chloroplast DNA markers from different Aporocactus populations and related genera, and ecological niche modeling techniques were also employed. Results: The phylogenetic analyses indicated that Aporocactus is composed of only two species: A. flagelliformis and A. martianus. Additionally, the phylogenetic analyses corroborated that Aporocactus is an early diverging group related to Weberocereus and Selenicereus. Finally, niche modeling and niche identity testing indicated that the niches of the two species of Aporocactus are significantly differentiated and niches are more different than would be expected by chance. Conclusions: Despite being a genus with only two species, Aporocactus represents a useful model for investigating such topics as the ecology of pollination, genetic populations, and flower development to characterize the evolution of these specialized cacti.

Background: Acaciella (Mill.) Britton & Rose is a Neotropical genus, whose species were within the subgenus Aculeiferum (tribe Acacieae), due to morphological similarities. Molecular studies reflect a close phylogenetic relationship with the genus Calliandra (tribe Ingeae). At present, studies of floral development are lacking for Acaciella, which could provide morphological evidence related to the evolutionary history of both tribes. Questions: Will the floral development patterns of Acaciella angustissima be similar to those reported for species of Acacieae and Ingeae tribes? Studied species: Acaciella angustissima (Mill.) Britton & Rose Study site and dates: Pie de Vaca, Tepexi de Rodríguez, Puebla, Mexico, May 2014. Methods: Flower buds and mature inflorescences were collected and dissected for their observation with the scanning electron microscope. Results: Andromonoecious species with flowers in capitate inflorescences. The inflorescence maturation is acropetal and slightly asynchronous. The flowers are actinomorphic and have a floral nectary at the base of the filaments. The patterns of inception are simultaneous in the perianth and the androecium. The carpel inception is precocious, prior to the appearance of stamen buds, even in male flowers. Conclusions: A. angustissima has particular ontogenetic characteristics, such as the asynchronous maturation of the flower meristems in the inflorescence and the simultaneous emergence of the androecium. It shares with the tribe Ingeae the acropetal inception of the floral meristems in the inflorescence, and with Acacieae and Ingeae the simultaneous inception of the corolla and the precocious inception of the carpel.

Background: The morphometric and phenological variation of the wild common beans from Durango, Mexico has been little explored. The ex situ records of phenological and morphometric attributes, germination and yield of common bean from five wild populations of Durango, Mexico was determined. Besides, the in situ and ex situ comparison of morphometric characters of the same populations was carried out. Hypotheses: Genetic and environmental factors have contributed in a variable way to the phenotypic differentiation of wild common bean. Studied species: Phaseolus vulgaris L. Study site and dates: Five locations in Durango, Mexico. September 2018 to November 2019. Methods: Ex situ phenological, morphometric, germination and yield data were registered. Morphometric characters were compared in situ and ex situ. Data were subjected to ANOVA, principal components, cluster and canonical correspondence. Results: Most of the morphometric features of pods and seeds had a genetic determinism revealed. Altitude was the main environmental factor that determined patterns of interaction with provenance. Scarification favored higher germination potentials in wild beans than a cultivated variety analyzed as a reference. In general, the ex situ conditions stimulated the development of larger pods, seeds and leaves, and more seeds than the in situ conditions. Conclusions: Different attributes of the wild populations of P. vulgaris analyzed have responded variably to environmental changes, mainly in altitude, through genotype-environment interactions. That variation provides a basis for understanding the adaptive potential and supporting conservation programs and the development of cultivars. Translate stop   Translate stop   Translate stop  

Background: The plant community in southern Texas and the adjacent region in Mexico is Tamaulipan thornscrub (MET). However, the recently published proposals for quantitative hierarchical classification have evidenced the presence of more communities and the need for quantitative descriptions of these associations to determine their conservation status. Question: What is the structure and floristic composition of a semi-thorn shrubland in Reynosa’s northwestern region? Studied species: Tamaulipan low semi-thorn scrubland. Study site and dates: Hills in Reynosa’s northwestern region (Tamaulipas), Mexico. August 2018-July 2019. Methods: Abundance, height and coverage of each plant species were measured on 33 plots of 10 × 10 m. Horizontal structure was analyzed by Importance Value Index, vertical structure was estimated through a modification of the Pretzsch Index and in addition alpha diversity indices were calculated. Results: Richness was 55 species, within 54 genera and 25 families. The importance values were centered mainly in small, spineless shrub species (Lippia graveolens, Calliandra conferta, Turnera diffusa and Krameria ramosissima). The vertical structure presented four defined strata with 50 % of species equally represented in all strata and the remaining 50 % restricted to a single stratum (A = 2.86, Amax = 5.39, Arel = 52.98 %). The species with the highest proportional density were distributed only in stratum IV (0-1.12 m). Conclusions: The community is a clearly defined low semi-thorn scrubland. The structural characteristics indicate that it can be a possible transition plant association between MET and piedmont scrub. This reinforces the proposals of the recently published classification systems. Translate stop   Translate stop  

Background: Protective role of salicylic acid against drought has been widely reported, but its effects on Zinnia elegansremain unknown. Hypotheses: Foliar salicylic acid (SA) improves water status, pigments, and antioxidant systems of Zinnia plants under drought stress. Studied species: Z. elegans (cv. Dreamland) were purchased from Chanan Seeds Store Lahore, Pakistan. Study site and dates: MNS University of Agriculture, Multan, Punjab, Pakistan; March-May, 2018. Methods: After two weeks of transplanting, one set of seedlings was exposed to drought stress (60 % field capacity, FC) while other control set was maintained at 100 % FC. Foliar SA (100 mg L-1) was applied to plants at drought initiation. Results: Foliar SA treatment to water stressed plants (60 % FC) increased the leaf area (46.89 cm2), shoot and root lengths (25 cm and 26.67 cm, respectively), leaf relative water content (75.98 %); chlorophyll a (0.68 mg g-1), chlorophyll b (0.38 mg g-1) and carotenoid concentrations (1.10 mg g-1); and catalase (116.67 U min-1 mg-1 protein), guaiacol peroxide (72 U min-1 mg-1 protein) and superoxide dismutase (93 U min-1 mg-1 protein) activities. Conclusions: Foliar SA could be used to minimize impacts of water stress in Zinnia plants.

Background: Hechtioideae is a group of Bromeliaceae that is distributed in Megamexico III. In recent years, evolutionary relationships within this lineage have been studied, however, the biogeography of these plants have not yet been explored from a phylogenetic framework. The integration of geographic and phylogenetic information in the evolutionary study of organisms has facilitated the identification of patterns, as well as the exploration of new hypotheses that allow understanding the processes that have influenced the evolutionary history of lineages. Questions and/or Hypotheses: What is the biogeographic history of this lineage? How Hechtioideae has diversified over time? Results: The Neotropical region has the highest species richness of Hechtioideae and the Mexican Transition Zone is the area with the greatest phylogenetic diversity. This lineage presented its highest diversification rate during the late Miocene and Pleistocene (6.5-1 Ma). The ancestral area of the group corresponds to the Neotropical region and the Mexican Transition Zone. In addition, Hechtioideae spread across their current ranges through multiple dispersal events associated with climatic and geological events during the last 10 Ma. Conclusions: Hechtioideae is a group of recent origin whose evolutionary history has been strongly influenced by geological and climatic events over the past 10 Ma, such as the glacial and interglacial periods of the Pleistocene and the great tectonic and volcanic activity that led to the formation of the Trans-Mexican Volcanic Belt.

Background: In mezcal industry, Agave salmiana leaves are a crop residue and a potential source of fructans. Agave fructans are a soluble fiber that can act as prebiotic in gut microbiota. Questions and Hypotheses: The molecular weight distribution of agave fructans extracted from leaves of Agave salmiana depends on the region where agaves growth and on the subspecies. Studied species: Agave salmiana Otto ex Salm Dyck, spp. salmiana and Agave salmiana spp. crassispina. Study site: Twelve municipalities from Guanajuato México were sampled: Ocampo, San Felipe, San Diego de la Unión, Victoria, Xichú, Atarjea, Dolores Hidalgo, Doctor Mora, Santa Catarina, Tierra Blanca, San Miguel Allende and Comonfort. Methods: The base of the leaf close to the stem of Agave salmiana ssp. salmiana and A. salmiana ssp. crassispina plants, six years old, were harvested. Water soluble carbohydrates were extracted, the content molecular weight distribution of fructans was determined by HPLC-SEC. Results: An average of 0.7 % of soluble carbohydrates was recovered from the leaves. The molecular weight distribution of Agave salmiana fructans was: number average molecular weight: 3,209 g/mol; average molecular weight: 5,046 g/mol; number average degree of polymerization: 19; weight average degree of polymerization: 30. High polymerization degree fructans content was greater in Agave salmiana spp. salmiana (55 %) than in Agave salmiana spp. crassispina (47 %). Conclusions: The leaves of Agave salmiana contain a low proportion of high-molecular-weight fructans, compared to commercial agave fructans. The results demonstrated the technical feasibility to obtain fructans from Agave salmianaleaves.

Background: Plants and bees have coevolved throughout geological time, establishing a mutualistic relationship that results in feeding/resource obtention by bees and the reproductive success of angiosperms. Questions and Hypotheses: What is the floristic composition of the vegetation visited by bees in the Caatinga? How are pollen grains from Caatinga bee plant species characterized? Do pollen grains of bee plant species present characters that could be associated with the pollination process? Studied species: We studied the pollen grains of 45 bee plant species belonging to 41 genera and 23 angiosperm families. Among the studied species, 37 % are endemic to Brazil, and eight species are endemic to the Caatinga biome. Study site and dates: Apiary within the Caatinga biome, in the State of Bahia, Brazil. Climate warm semiarid. Fieldwork was carried out between August 2016 and June 2017. Methods: Plants in bloom and being visited by Apis mellifera were collected during biweekly field expeditions, herborized, identified, and deposited at the HUNEB herbarium. Pollen grains were acetolyzed, characterized, and microphotographed under light microscopy. Results: Forty-five bee plants were collected and classified according to field observations and specialized literature. Pollen morphology was variable, and nine species had their pollen morphology described for the first time. The apertures of the studied pollen grains were mainly tricolporate (44 %), pantoporate (15 %), and inaperturate (13 %), and exine ornamentation was mainly (micro)reticulate (46 %) and (micro)echinate (33 %). Conclusions: Our results suggest that bee plants present a set of palynological characters that may favor entomophily. Translate stop   Translate stop  

Background: Parasitic angiosperms obtain water or nutrients from a host. They are considered holoparasites if they obtain water and photosynthates, or hemiparasites if they obtain water and minerals. Hemipararasitic plants are divided into obligate parasites if they depend on the host during their entire life cycle; or facultative if they do not require the host to survive. Obligate hemiparasites include to mistletoes, which can also parasitize other mistletoes, thus being epiparasitic plants. For Mexico 14 families, 41 genera and 411 species of parasitic plants are considered. Questions: What is the diversity of parasitic angiosperms in Morelos? Studied species: Parasitic angiosperms. Study site and dates: Morelos state, Mexico. Methods: We reviewed 650 herbarium specimens from nine herbaria (ENCB, FCME, HUAP, HUMO, IEB, MEXU, RSA, UAMIZ, XAL) and 15 digital collections (ARIZ, ASU, CM, COLO, F, GH, IND, LL, MO, NMC, NY, RM, UCR, UTC, TEX). A total of 178 specimens were collected in nineteen municipalities. The names of each taxon were validated in Tropicos, The Plant List, and International Plant Names Index. Results: Eleven families, 22 genera, 60 species of parasitic plants were recorded in Morelos. Of total, 14 species are holoparasites, and 19 are facultative hemiparasites and 27 are obligate hemiparasites. Ten species of epiparasitic mistletoes were reported, with five new records of previously undocumented interactions. Conclusions: Parasitic plants represent 1.69 % of angiosperm richness in Morelos, 24 species are endemic to Mexico. The greatest diversity is found in the Natural Protected Areas. Translate stop   Translate stop  

Background: Obligate outcrossing species (such as dioecious species) are more vulnerable to habitat fragmentation than self-compatible hermaphrodite trees. Questions: What is the effect of restoration intervention in the populations of dioecious, monoecious, and hermaphrodite tree species in permanent agricultural landscapes? Study site and dates: 8-year-old restoration settings in the seasonally dry tropical forest in Sierra de Huautla Biosphere Reserve, Morelos, Mexico. Methods: We measure richness and density of dioecious, monoecious, and hermaphrodite tree species with Diameter at Breast Height ≥ 2.5 cm in perturbed, 8-year-old restoration settings (plantings and natural succession) and conserved habitats. Results: Overall habitats, 2,042 trees from 46 species in 18 families were identified; the highest percentage of species and trees were hermaphrodites (63 % of species and 78 % of trees), the lowest percentage of species were monoecious (9 %) and the lowest percentage of trees (10 %) were dioecious. In the plantings were registered the largest number of species (37 species) and in the conserved habitat the largest number of trees (852 trees). Density and richness of dioecious, monoecious, and hermaphrodite species did not differ by habitat, contrary to our predictions. For dioecious trees, the restored and conserved habitats showed similar composition heterogeneity. Composition of hermaphrodites in agricultural landscapes differed the most with the conserved habitat. Conclusions: Dioecious and monoecious species are favored in agricultural landscapes due to their use value. Selection of species for restoration plantings should consider sexual systems of trees to recover not only forest structure but also ecosystem function.