Dinâmica evolutiva de Cucurbita argyosperma do centro mesoamericano de domesticação por meio de marcadores moleculares SSR

The objective of this work was to evaluate the evolutionary dynamics of the wild-weedy-domestic gene pool of Cucurbita argyrosperma squash by estimating the levels of genetic diversity and gene flow in the putative area of its domestication. Nine populations were collected, and DNA was extracted from young leaves harvested separately from approximately 20 individuals in each population. The DNA fragments were amplified with eight pairs of SSR primers and separated by electrophoresis in 5% denaturing polyacrylamide gels. Genetic diversity and the amount of gene flow were estimated in the populations, and Bayesian grouping was used to determine the levels of gene infiltration and probability of ancestry. The ethnobotanical exploration indicated that the evolutionary dynamics in the area occurred under five different ecological scenarios. Eighty-seven alleles with 75% to 100% polymorphic loci were identified. The greater genetic diversity in the weedy-domestic populations may have been the product of recombination due to the high gene flow between these populations promoted by pollinators and human selection. There is high gene flow between the wild and cultivated populations of C. argyrosperma in its domestication centre, highlighting the importance of conserving and maintaining these genetic resources. O objetivo deste trabalho foi avaliar a dinâmica evolutiva do pool genético silvestre-arvense-doméstico da abóbora (Cucurbita argyrosperma) ao estimar os níveis de diversidade genética e o fluxo gênico em sua provável área domesticação. Foram coletadas nove populações, tendo-se extraído o DNA de folhas jovens de cerca de 20 plantas de cada população. Os fragmentos de DNA foram amplificados por meio de oito pares de iniciadores de sequência simples repetida (SSR) e separados por eletroforese em 5% de gel de desnaturação de poliacrilamida. Estimaram-se a diversidade genética e o fluxo gênico para as populações, e utilizou-se o agrupamento bayesiano para determinar os níveis de infiltração gênica e probabilidade de ancestralidade. A investigação etnobotânica mostrou que a dinâmica evolutiva na área ocorreu em cinco cenários ecológicos diferentes. Foram identificados 87 alelos com 75 e 100% de loci polimórficos. A maior diversidade genética nas populações arvense-domésticas pode ter sido resultante da recombinação devido ao alto fluxo gênico entre estas populações, ocasionado pelos polinizadores e pela seleção humana. Há grande fluxo gênico entre as populações silvestres e cultivadas de C. argyrosperma no centro de domesticação, o que indica a importância da conservação e da manutenção destes recursos genéticos

Potencial hortícola de los zapotes negros, <i>Diospyros</i> spp. (Ebenaceae)

Se exploró el potencial hortícola del género Diospyros (Ebenaceae) mediante análisis biogeográficos, climáticos, morfológicos y etnobotánicos. Los análisis geográficos permitieron identificar las áreas óptimas para la conservación y el aprovechamiento de 20 especies. Con aquellas conocidas como Zapotes Negros, D. nigra y D. Conzattii, se aplicó un análisis climático. Por último se estudió la variabilidad morfológica asociada al nivel de manejo en tres zonas de México. Veracruz y Península de Yucatán fueron las áreas donde convergen el mayor número de especies. Las adaptaciones climáticas de los zapotes estudiados les permiten ser cultivados comercialmente en gran parte del país. D. nigra reveló diferencias significativas entre los individuos silvestres, tolerados, fomentados y cultivados: asociados principalmente a la firmeza del pericarpio, el tiempo de maduración y el tamaño del arilo. Características útiles para promover el consumo y facilitar el transporte.The horticultural potential of the Diospyros spp. (Ebenaceae) was explored using biogeographic, climatic, morphological and entnobotanical analyzes. The geographical analysis allowed identification of optimal areas for conservation and use of 20 species. The two species known as Black Sapot, D. nigra and D. conzattii, were selected for climate analysis. Finally, morphological variability of individuals associated with level management was studied in three areas of Mexico and associated with aspects an components of the domestication process. Veracruz and the Yucatan were the places where the largest number of species and sections of the genus converge. Climatic adaptation of the studied sapots allow them to be grown commercially in a large part of the country. Significant differences were exhibited among wild, tolerated, promoted, and cultivated D. nigra individuals. These differences were associated with pericarp firmness, time of maturation and size of aryl. Useful featurs to promote consumtion and facilitate transport.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Potencial hortícola de los zapotes negros, <i>Diospyros</i> spp. (Ebenaceae)

Se exploró el potencial hortícola del género Diospyros (Ebenaceae) mediante análisis biogeográficos, climáticos, morfológicos y etnobotánicos. Los análisis geográficos permitieron identificar las áreas óptimas para la conservación y el aprovechamiento de 20 especies. Con aquellas conocidas como Zapotes Negros, D. nigra y D. Conzattii, se aplicó un análisis climático. Por último se estudió la variabilidad morfológica asociada al nivel de manejo en tres zonas de México. Veracruz y Península de Yucatán fueron las áreas donde convergen el mayor número de especies. Las adaptaciones climáticas de los zapotes estudiados les permiten ser cultivados comercialmente en gran parte del país. D. nigra reveló diferencias significativas entre los individuos silvestres, tolerados, fomentados y cultivados: asociados principalmente a la firmeza del pericarpio, el tiempo de maduración y el tamaño del arilo. Características útiles para promover el consumo y facilitar el transporte.The horticultural potential of the Diospyros spp. (Ebenaceae) was explored using biogeographic, climatic, morphological and entnobotanical analyzes. The geographical analysis allowed identification of optimal areas for conservation and use of 20 species. The two species known as Black Sapot, D. nigra and D. conzattii, were selected for climate analysis. Finally, morphological variability of individuals associated with level management was studied in three areas of Mexico and associated with aspects an components of the domestication process. Veracruz and the Yucatan were the places where the largest number of species and sections of the genus converge. Climatic adaptation of the studied sapots allow them to be grown commercially in a large part of the country. Significant differences were exhibited among wild, tolerated, promoted, and cultivated D. nigra individuals. These differences were associated with pericarp firmness, time of maturation and size of aryl. Useful featurs to promote consumtion and facilitate transport.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Impact of Human Management on the Genetic Variation of Wild Pepper, Capsicum annuum var. glabriusculum

Management of wild peppers in Mexico has occurred for a long time without clear phenotypic signs of domestication. However, pre-domestication management could have implications for the population's genetic richness. To test this hypothesis we analysed 27 wild (W), let standing (LS) and cultivated (C) populations, plus 7 samples from local markets (LM), with nine polymorphic microsatellite markers. Two hundred and fifty two alleles were identified, averaging 28 per locus. Allele number was higher in W, and 15 and 40% less in LS and C populations, respectively. Genetic variation had a significant population structure. In W populations, structure was associated with ecological and geographic areas according to isolation by distance. When LM and C populations where included in the analysis, differentiation was no longer apparent. Most LM were related to distant populations from Sierra Madre Oriental, which represents their probable origin. Historical demography shows a recent decline in all W populations. Thus, pre-domestication human management is associated with a significant reduction of genetic diversity and with a loss of differentiation suggesting movement among regions by man. Measures to conserve wild and managed populations should be implemented to maintain the source and the architecture of genetic variation in this important crop relative

Cocoteros en las Américas

It has been clearly established that the Portuguese introduced coconuts to the Cape Verde islands in 1499, and these supplied the Atlantic coasts and the Caribbean in the 1500s. By contrast, early 16th century reports of coconuts on the Pacific coast of Panama are controversial. Recent DNA analysis of modern coconut populations there shows them to be similar to Philippine varieties, agreeing with morphometric analysis. Hence, coconuts must have been brought by boat from the western Pacific, but no archaeological, ethnobotanical or linguistic evidence for pre-Columbian coconuts has been found. Thus, the most parsimonious explanation is that coconuts were introduced to Panama after Spanish conquest, as supported by DNA analysis and historical records of Spanish voyages. New collections along the Pacific coast, from Mexico to Colombia, are increasing the sampling for genetic analysis, and further work in the Philippines is suggested to test probable origins. Unless new archaeological discoveries prove otherwise, the strong hypothesis of Philippine origin should direct future research on the sources of American Pacific coast coconuts. © 2013 The New York Botanical Garden

Coconuts in the Americas [Cocoteros en las Americas]

It has been clearly established that the Portuguese introduced coconuts to the Cape Verde islands in 1499, and these supplied the Atlantic coasts and the Caribbean in the 1500s. By contrast, early 16th century reports of coconuts on the Pacific coast of