32 research outputs found

    Independent Origins of Cultivated Coconut (Cocos nucifera L.) in the Old World Tropics

    Get PDF
    As a portable source of food, water, fuel, and construction materials, the coconut (Cocos nucifera L.) played a fundamental role in human migrations and the development of civilization across the humid tropics. Here we investigated the coconut's domestication history and its population genetic structure as it relates to human dispersal patterns. A sample of 1,322 coconut accessions, representing the geographical and phenotypic diversity of the species, was examined using ten microsatellite loci. Bayesian analyses reveal two highly genetically differentiated subpopulations that correspond to the Pacific and Indo-Atlantic oceanic basins. This pattern suggests independent origins of coconut cultivation in these two world regions, with persistent population structure on a global scale despite long-term human cultivation and dispersal. Pacific coconuts show additional genetic substructure corresponding to phenotypic and geographical subgroups; moreover, the traits that are most clearly associated with selection under human cultivation (dwarf habit, self-pollination, and “niu vai” fruit morphology) arose only in the Pacific. Coconuts that show evidence of genetic admixture between the Pacific and Indo-Atlantic groups occur primarily in the southwestern Indian Ocean. This pattern is consistent with human introductions of Pacific coconuts along the ancient Austronesian trade route connecting Madagascar to Southeast Asia. Admixture in coastal east Africa may also reflect later historic Arab trading along the Indian Ocean coastline. We propose two geographical origins of coconut cultivation: island Southeast Asia and southern margins of the Indian subcontinent

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

    Get PDF
    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

    Microsatellite diversity and genetic structure among common bean (Phaseolus vulgaris L.) landraces in Brazil, a secondary center of diversity

    Get PDF
    Brazil is the largest producer and consumer of common bean (Phaseolus vulgaris L.), which is the most important source of human dietary protein in that country. This study assessed the genetic diversity and the structure of a sample of 279 geo-referenced common bean landraces from Brazil, using molecular markers. Sixty-seven microsatellite markers spread over the 11 linkage groups of the common bean genome, as well as Phaseolin, PvTFL1y, APA and four SCAR markers were used. As expected, the sample showed lower genetic diversity compared to the diversity in the primary center of diversification. Andean and Mesoamerican gene pools were both present but the latter gene pool was four times more frequent than the former. The two gene pools could be clearly distinguished; limited admixture was observed between these groups. The Mesoamerican group consisted of two sub-populations, with a high level of admixture between them leading to a large proportion of stabilized hybrids not observed in the centers of domestication. Thus, Brazil can be considered a secondary center of diversification of common bean. A high degree of genome-wide multilocus associations even among unlinked loci was observed, confirming the high level of structure in the sample and suggesting that association mapping should be conducted in separate Andean and Mesoamerican Brazilian samples

    Sustainability of the traditional management of Agave genetic resources in the elaboration of mezcal and tequila spirits in western Mexico

    No full text
    Over the last 30 years, cultivation of Agave tequilana Weber var blue for industrial production of tequila, has generated soil erosion, chemical pollution, displacement of traditional food crops and traditional Agave landraces used for preparing "mezcals" in the Appellation of Origin Tequila area. It is also associated with harmful cycles 8-10 years long of surplus-shortfall availability of raw material. Mezcal is the common traditional name given in Mexico to spirits like tequila, prepared with Agave tissue. We examined the traditional strategies of management of the Agave genetic resources for elaborating mezcal and tequila spirits by people of southern Jalisco, Mexico, analyzing the bases of their sustainable management, compared with management of the industrial tequila system. We found that mezcal spirits are prepared with different landraces of A. angustifolia Haw. and A. rhodacantha Trel. which are cultivated as living fences within the "milpa", the traditional Mesoamerican multi-crop system. The whole system allows simultaneous production of agricultural, livestock and forest resources, permitting the adjustment of mezcal production to demand. Agave borders and terraces are laid out perpendicular to slopes to increase rainfall capture and filtration, and decrease soil erosion. The high species richness creates niche heterogeneity, substantially reducing pest and disease incidence. Genetic and morphological analyses indicated that traditional management and selection of A. angustifolia landraces have produced high genetic diversity (HBT = 0.438 ± 0.003) and structure (θB = 0.408) when compared with wild populations (HBT = 0.428 ± 0.015; θB = 0.212). Morphological differentiation is associated to artificial selection pressures. Differential precocity of Agave landraces and scaled planting favors continuous, year round spirit production. Growers directly market their mezcals, and a portion of the profits is reinvested in the parcel to ensure system continuity. The technological advantages of the traditional mezcal system could attenuate some challenges caused by the tequila industrial agriculture. © 2012 Springer Science+Business Media Dordrecht

    Sympathetic activity and response to ACE inhibitor (enalapril) in normotensive obese and non-obese subjects

    No full text
    Over the last 30 years, cultivation of Agave tequilana Weber var blue for industrial production of tequila, has generated soil erosion, chemical pollution, displacement of traditional food crops and traditional Agave landraces used for preparing "mezcals" in the Appellation of Origin Tequila area. It is also associated with harmful cycles 8-10 years long of surplus-shortfall availability of raw material. Mezcal is the common traditional name given in Mexico to spirits like tequila, prepared with Agave tissue. We examined the traditional strategies of management of the Agave genetic resources for elaborating mezcal and tequila spirits by people of southern Jalisco, Mexico, analyzing the bases of their sustainable management, compared with management of the industrial tequila system. We found that mezcal spirits are prepared with different landraces of A. angustifolia Haw. and A. rhodacantha Trel. which are cultivated as living fences within the "milpa", the traditional Mesoamerican multi-crop system. The whole system allows simultaneous production of agricultural, livestock and forest resources, permitting the adjustment of mezcal production to demand. Agave borders and terraces are laid out perpendicular to slopes to increase rainfall capture and filtration, and decrease soil erosion. The high species richness creates niche heterogeneity, substantially reducing pest and disease incidence. Genetic and morphological analyses indicated that traditional management and selection of A. angustifolia landraces have produced high genetic diversity (HBT = 0.438 0.003) and structure (?B = 0.408) when compared with wild populations (HBT = 0.428 0.015; ?B = 0.212). Morphological differentiation is associated to artificial selection pressures. Differential precocity of Agave landraces and scaled planting favors continuous, year round spirit production. Growers directly market their mezcals, and a portion of the profits is reinvested in the parcel to ensure system continuity. The technological advantages of the traditional mezcal system could attenuate some challenges caused by the tequila industrial agriculture. " 2012 Springer Science+Business Media Dordrecht.",,,,,,"10.1007/s10722-012-9812-z",,,"http://hdl.handle.net/20.500.12104/44878","http://www.scopus.com/inward/record.url?eid=2-s2.0-84871957066&partnerID=40&md5=07ac844837a6210040555de2ad91f7b7",,,,,,"1",,"Genetic Resources and Crop Evolution",,"3

    Diversity and structure of landraces of Agave grown for spirits under traditional agriculture: A comparison with wild populations of A. angustifolia (Agavaceae) and commercial plantations of A. tequilana

    No full text
    Traditional farming communities frequently maintain high levels of agrobiodiversity, so understanding their agricultural practices is a priority for biodiversity conservation. The cultural origin of agave spirits (mezcals) from west-central Mexico is in the southern part of the state of Jalisco where traditional farmers cultivate more than 20 landraces of Agave angustifolia Haw. in agroecosystems that include in situ management of wild populations. These systems, rooted in a 9000-year-old tradition of using agaves as food in Mesoamerica, are endangered by the expansion of commercial monoculture plantations of the blue agave variety (A. tequilana Weber var. Azul), the only agave certified for sale as tequila, the best-known mezcal. Using intersimple sequence repeats and Bayesian estimators of diversity and structure, we found that A. angustifolia traditional landraces had a genetic diversity (H BT = 0.442) similar to its wild populations (HBT = 0.428) and a higher genetic structure (?B = 0.405; ?B =0. 212). In contrast, the genetic diversity in the blue agave commercial system (HB = 0.118) was 73% lower. Changes to agave spirits certification laws to allow the conservation of current genetic, ecological and cultural diversity can play a key role in the preservation of the traditional agroecosystems
    corecore