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1.
CienciaUAT ; 18(1): 6-24, jul.-dic. 2023. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1513968

RESUMO

RESUMEN El Bosque Mesófilo de Montaña (BMM) del centro de Veracruz, México, representa un paisaje alterado por actividades antrópicas, por lo que es necesario evaluar el potencial evolutivo y adaptativo de las aves refugiadas en el sitio, las cuales se enfrentan a un paisaje con un gradiente heterogéneo. El objetivo de este estudio fue determinar la diversidad de aves en fragmentos de BMM y vegetación secundaria (VS), en el predio Finca La Pastoría, Huatusco, Veracruz, así como, asociar su presencia y/o alimentación a cada hábitat evaluado. Se identificaron las especies y número de individuos en 14 sitios de observación de aves, con el método de muestreo basado en conteo por puntos con radio fijo de 30 m. Se registraron 100 especies pertenecientes a 33 familias y 15 órdenes. En el BMM se identificaron 916 individuos, correspondientes a 89 especies, y en VS 331 individuos de 54 especies, encontrando diferencias significativas de diversidad de aves entre coberturas de muestreo. Destacan los registros de Dendrortyx barbatus, Leptotila verreauxi y Vireo griseus, por ser endémicas. La primera está clasificada en peligro de extinción, mientras que la segunda se encuentra sujeta a protección especial y la tercera amenazada. También se registraron Pionus senilis, especie amenazada; Falco peregrinus, Micrastur semitorquatus, Passerina ciris, Psarocolius montezuma, Myadestes occidentalis y Amazona albifrons, sujetas a protección especial. Este estudio brinda información sobre cómo la avifauna hace uso diferencial de dos coberturas de vegetación, la cual puede servir para generar estrategias sustentables para el manejo y conservación del bosque.


ABSTRACT The Cloud Forest (CF) in central Veracruz, Mexico, represents a landscape that has been altered by anthropic activities. Therefore, it is necessary to evaluate the evolutionary and adaptive potential of the birds sheltered in the site, which face a landscape with a heterogeneous gradient. The objective of the study was to describe the diversity of birds in fragments of CF and secondary vegetation (VS), in the property "Finca La Pastoría", Huatusco, Veracruz. The species and number of individuals in 14 bird watching sites were identified, with the sampling method based on counting points with a fixed radius of 30 m. 100 species from 33 families and 15 orders were recorded. In the CF, 916 individuals were identified, corresponding to 89 species, and in VS 331 individuals of 54 species, finding significant differences in bird diversity between sampling coverages. The records of Dendrortyx barbatus, Leptotila verreauxi and Vireo griseus stand out for being endemic and classified as endangered and threatened, respectively. Furthermore, Pionus senilis, a threatened species, as well as Falco peregrinus, Micrastur semitorquatus, Passerina ciris, Psarocolius montezuma, Myadestes occidentalis and Amazona albifrons, subject to special protection, were also recorded. This study provides information on how the birds make differential use of two vegetation covers, which can be used to generate sustainable strategies for forest management and conservation.

2.
PLoS One ; 17(6): e0269896, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35700205

RESUMO

Maize (Zea mays L.) is native to Mexico, in which wide genetic diversity can be found; however, maize is at risk of genetic erosion, and agroforestry systems (ASs) can be a strategy for conservation and sustainable use of this crop. The objective of this study was to evaluate the variation in the morpho-agronomic characteristics of three native maize races, Tuxpeño, Olotillo × Tuxpeño and Ratón × Tepecintle, cultivated in different AS in a tropical climate of Veracruz, Mexico, as well as its association with microclimatic conditions. In 2019, experiments were established in the localities La Gloria and La Luisa, Veracruz, where the three maize races are cultivated, in a randomized complete block design with three replications in a 3 × 4 factorial scheme (three native maize races and three AS arrrays, plus monoculture). Ten morpho-agronomic variables were recorded in each experiment and were analyzed by analysis of variance (ANOVA; Tukey's post-hoc test, all p ≤ 0.05) and principal component analysis (PCA). Six morpho-agronomic characteristics showed significant differences for the race × system interaction. Consistently standing out both in the Myroxylon with 2.8 m × 2.0 arrays and in the monoculture was the Olotillo × Tuxpeño race, as there were no variations (p ≥ 0.05) in 50% of its morpho-agronomic characteristics. The first three PCs explained 87.7% of the cumulative variance, determined by five variables of the ears, three of the grain and plant height, which were associated with temperature; therefore, the microclimatic conditions of the studied ASs are associated with the morpho-agronomic characteristics of the native maize races. The results show that ASs could be a strategy for the conservation and use of native corn germplasm and could allow the diversification of sustainable production for rural farmers.


Assuntos
Clima Tropical , Zea mays , Grão Comestível/genética , México , Zea mays/genética
3.
Animals (Basel) ; 12(4)2022 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-35203164

RESUMO

In the indigenous communities of central Veracruz, herds of creole sheep have been established and managed through traditional practices of crossing, but their genetic characteristics have never been examined in order to evaluate their state of endogamy, and to help the management programs to protect this genetic resource. The objective of the present study was to characterize the genetic diversity of three populations of creole sheep managed by indigenous communities in the central region of Veracruz, Mexico. Indigenous family producers of creole sheep were located and blood samples taken from 90 individual sheep from the municipalities of Tehuipango, Astacinga and Tlaquilpa, Veracruz. In the laboratory, the genomic DNA was extracted and genetic diversity characterized using four microsatellites (ILSTS11, ILSTS5, SRCRSP9 and OarFCB128) amplified by PCR and visualized on polyacrylamide gels. The four microsatellites were highly informative (PIC = 85%) and presented values of 0.6 to 0.81 of heterozygosity, with an average number of 16 alleles. According to the Hardy-Weinberg equilibrium model, three of the loci were not significant (p < 0.05), presumably this means that they do not deviate significantly from H-W predictions and there was slight genetic differentiation (FST = 0.025), along with a slight decrease in homozygotes (FIS = -0.021). According to the analysis of variance, 99% of the total variation was hosted at the individual level. It is concluded that the three creole sheep populations still present genetic diversity at the four loci and non-random pairings have occurred.

4.
Pathogens ; 10(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946626

RESUMO

The tick Amblyomma mixtum is an ectoparasite of veterinary and public health importance because of its role as a vector of zoonotic pathogens. However, little is known about A. mixtum intraspecific variability and if morphological differentiation exists between populations across its geographic range. This study aimed to determine by electron microscopy the morphological variability of A. mixtum populations in the state of Veracruz, which has a large livestock population among states in Mexico. Forty male and 40 female A. mixtum collected from the 10 natural regions of Veracruz state were analyzed microscopically to accomplish main component analysis for each sex. Clusters were calculated with the out-tree method and a dendrogram produced to group the specimens according to their morphometric characteristics. Using 10 main components, 77% of the morphological variation of the ticks was explained. This is a reflection of scarce intraspecific variation between females. The dendogram for females grouped six clusters of specimens with similar characteristics. Morphometric variability in males was described using eight main components. Limited intraspecific variation was also observed between males. In males, the dendogram yielded six groups with similar morphometric characteristics. Morphometric analyses confirmed that the only species from the Amblyomma cajennense complex that are parasites to livestock in Veracruz state is A. mixtum. The eryxenous nature of A. mixtum combined with the frequent movement of livestock hosts may contribute to the apparent homogeneous phenotype of this tick species in Mexico.

5.
Rev. biol. trop ; 67(4)sept. 2019.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1507544

RESUMO

El tomate (Solanum lycopersicum) es una de las principales hortalizas en el mundo debido a las importantes ganancias económicas que genera su comercialización; sin embargo, a pesar de que la especie es ampliamente cultivada en el mundo, su diversidad genética se considera restringida. Esto hace que su resistencia a plagas y enfermedades en las variedades actualmente cultivadas sea baja. Existe la forma silvestre S. l. var ceraciforme que se distribuye desde Suramérica (centro de origen) hasta México (área de domesticación), específicamente en la vertiente del Golfo de México en Veracruz. Como objetivo, se quiso identificar patrones de diversificación ambiental con los que se pudiesen inferir procesos de adaptación de las poblaciones en el área de domesticación con respecto a su centro de origen. Asimismo, se planteó proponer medidas de conservación y rescate del tomate S. l. var. cerasiforme. Se realizaron modelos de nicho ecológico (MNE) con Maxent versión 3.4.1 (evaluados con AUC y ROC-parcial) para determinar la idoneidad de las condiciones ambientales, incluyendo proyecciones del centro de domesticación al área de origen y viceversa. Esto se realizó con base en ocho variables de temperatura y precipitación. Los registros de tomate fueron tomados de fuentes bibliográficas y trabajo de campo. Seguidamente, se realizó la prueba de comparación de nichos (equivalencia y similitud), propuesta por Broennimann et al. (2012), para evaluar la similitud de condiciones ambientales en ambas regiones. Posteriormente, se realizó un análisis de varianza seguido de una prueba de comparación de medias (Tukey, P ≤ 0.05) con las ocho variables ambientales utilizadas. Los valores de AUC (0.93 y 0.80) y ROC-parcial obtenidos (1.86 y 1.71; P = 0.0001) de los MNE muestran que fueron buenos modelos predictores. Se observó que en el centro de México existen condiciones ambientales similares a las del centro de origen, a diferencia de la vertiente del Golfo de México donde son diferentes. La prueba de equivalencia mostró que la comparación ambiental entre ambas regiones es menos equivalente que lo esperado por azar (P = 0.003). Mientras tanto, la otra prueba indica que la similitud que existe entre ambas regiones también se puede obtener por azar (P = 0.683). También, se encontraron diferencias significativas en tres variables de temperatura y precipitación. En conclusión, el centro de origen y de domesticación de S. l. var. cerasiforme tienen características ambientales en común a pesar de la distancia geográfica, pero existen zonas geográficas (vertiente del Golfo de México en Veracruz) en el área de domesticación con condiciones ambientales diferentes a las de su centro de origen y con un potencial importante como bancos de germoplasma.


The tomato (Solanum lycopersicum) is one of the main horticultural crops in the world because of the important economic benefits that its commercialization generates. Even though the species is widely cultivated in the world, it is susceptible to pests, diseases, and environmental stresses due to the loss of its genetic diversity. There is a wild form called S. l. var ceraciforme that is distributed from South America (its center of origin) to Mexico (its area of domestication), specifically on the slope of the Gulf of Mexico in Veracruz. Due to the large genetic diversity of these wild tomatoes, it is important to improve its crop. The objective of this investigation was to identify patterns of environmental diversification of the tomato, infer the processes of adaptation of the populations in the area of domestication with respect to their center of origin and propose measures of conservation and variation of S. l. var. cerasiforme. We generated two ecological niche models (MNE) with Maxent version 3.4.1 (evaluated with AUC and partial-ROC) to determine the suitability of environmental conditions including their respective projections from the domestication center to the area of origin and vice versa. We used eight variables of temperature and precipitation. Additionally, we included tomato records from bibliographical sources and fieldwork. We also used the niche comparison test (equivalency and similarity) proposed by Broennimann et al. (2012) to evaluate the similarity of environmental conditions in both regions. Subsequently, we carried out an analysis of variance followed by a mean comparison test (Tukey, P ≤ 0.05) with all environmental variables measured. The values of AUC (0.93 and 0.80) and partial-ROC (1.86 and 1.71, P = 0.0001) of the MNE showed that they were good predictive models. We observed that, in the center of Mexico, there are environmental conditions similar to those of the center of origin, unlike the slope of the Gulf of Mexico where they are different. The equivalency test showed that the environmental comparison between both regions is less similar than expected by chance (P = 0.003). The similarity test indicated that the existing similarity between both regions can also be obtained by chance (P = 0.683). We also found significant differences in three temperature and precipitation variables. In conclusion, we determined that the center of origin and domestication of S. l. var. cerasiforme has similar environmental characteristics despite the geographic distance; nevertheless, there are geographical zones (the Gulf of Mexico in Veracruz) in the area of domestication with different environmental conditions. Those places have the potential to contain valuable germplasms.

6.
Rev Biol Trop ; 60(1): 425-36, 2012 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-22458236

RESUMO

Crocodylus moreletii, an extinction threatened species, represents an emblem for tropical ecosystems in Mexico. Surprisingly, there is a lack of information about their genetic constitution, which should be evaluated for a proper management ex situ and for making decisions on the release of crocodiles into natural habitats. The aim of this study was to characterize and compare the genetic variability of four populations of C. moreletii (two wild versus two born ex situ). Through PCR were amplified seven microsatellite polymorphic loci, however a heterozygote deficit, diminished by the presence of null alleles, was found in the populations (average Ho=0.02). The AMOVA indicated that the highest proportion of genetic variability is within populations, and a limited genetic differentiation among populations (average F(ST)=0.03), probably due to high inbreeding index (average F(IS)=0.97). When comparing the genetic variability between and within other crocodilian species, we found that in C. moreletii is well below those reported. We concluded that the limited genetic variability in ex situ born populations is probably due to a founder effect derived from the social structure of their progenitors, and by the bottleneck effect, inferred by the limited effective population size, that historically characterizes their natural distribution in wild populations.


Assuntos
Jacarés e Crocodilos/genética , Variação Genética/genética , Genética Populacional , Repetições de Microssatélites/genética , Alelos , Jacarés e Crocodilos/classificação , Animais , Feminino , Frequência do Gene , Endogamia , Masculino , México , Reação em Cadeia da Polimerase
7.
Rev. biol. trop ; 60(1): 425-436, Mar. 2012. graf, tab
Artigo em Espanhol | LILACS | ID: lil-657790

RESUMO

Genetic variability in captive populations of Crocodylus moreletii (Crocodylia: Crocodylidae) using microsatellites markers. Crocodylus moreletii, an extinction threatened species, represents an emblem for tropical ecosystems in Mexico. Surprisingly, there is a lack of information about their genetic constitution, which should be evaluated for a proper management ex situ and for making decisions on the release of crocodiles into natural habitats. The aim of this study was to characterize and compare the genetic variability of four populations of C. moreletii (two wild versus two born ex situ). Through PCR were amplified seven microsatellite polymorphic loci, however a heterozygote deficit, diminished by the presence of null alleles, was found in the populations (average H O=0.02). The AMOVA indicated that the highest proportion of genetic variability is within populations, and a limited genetic differentiation among populations (average F ST=0.03), probably due to high inbreeding index (average F IS=0.97). When comparing the genetic variability between and within other crocodilian species, we found that in C. moreletii is well below those reported. We concluded that the limited genetic variability in ex situ born populations is probably due to a founder effect derived from the social structure of their progenitors, and by the bottleneck effect, inferred by the limited effective population size, that historically characterizes their natural distribution in wild populations.


Crocodylus moreletii representa un emblema para los ecosistemas tropicales de México pero actualmente está amenazada por extinción. Sorprendentemente, hay una falta de información de su constitución genética, que debe ser evaluada para un manejo apropiado ex situ y para toma de decisiones en la liberación de cocodrilos a su hábitat natural. El objetivo del estudio fue caracterizar y comparar la variabilidad genética de cuatro grupos poblacionales de C. moreletii (dos silvestres y dos nacidas ex situ). Mediante PCR se amplificaron siete loci de microsatélites polimórficos, sin embargo se encontró déficit de heterocigotos en las poblaciones (promedio H O=0.02) mermado por la presencia de alelos nulos. El AMOVA indicó que la mayor proporción de variabilidad genética se encuentra dentro de las poblaciones y una limitada diferenciación genética entre poblaciones (promedio F ST =0.03), probablemente debida al alto índice de endogamia (promedio F IS=0.97). Al comparar la variabilidad genética inter e intra especies de cocodrilianos, encontramos que en C. moreletii está muy por debajo de los reportados. Se concluye que la limitada variabilidad genética de las poblaciones nacidas ex situ probablemente se debe al efecto fundador derivado de la estructura social de sus progenitores, y de las poblaciones silvestres, por el efecto cuello de botella, inferido por el limitado tamaño efectivo de población que presentó históricamente en su distribución natural.


Assuntos
Animais , Feminino , Masculino , Jacarés e Crocodilos/genética , Genética Populacional , Variação Genética/genética , Repetições de Microssatélites/genética , Alelos , Jacarés e Crocodilos/classificação , Frequência do Gene , Endogamia , México , Reação em Cadeia da Polimerase
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