RESUMO
PREMISE OF THE STUDY: The poinsettia (Euphorbia pulcherrima) is the world's most economically important potted plant, but despite its preeminence it is not clear which wild populations are ancestral to the varieties cultivated around the world. Tradition holds that the U.S. envoy to Mexico J. R. Poinsett collected the progenitors of the over 300 varieties in global cultivation on an 1828 excursion to northern Guerrero State, Mexico. It is unknown whether the contemporary cultivars are descended from plants from Guerrero or whether germplasm from other parts of poinsettia's 2000 km long distribution entered into cultivation during the nearly 200 yr of subsequent poinsettia horticulture. METHODS: To identify the wild populations that likely gave rise to the cultivars and test this historical account, we sequenced plastid and nuclear DNA regions and modeled poinsettia's potential distribution. KEY RESULTS: The combination of nuclear and plastid haplotypes characterizing cultivars was found only in northern Guerrero. Distribution modeling indicated that suitable habitat conditions for wild poinsettias are present in this area, consistent with their likely wild status. CONCLUSIONS: Our data pinpoint the area of northern Guerrero as the cultivated poinsettia's probable ancestral region, congruent with the traditional account attributing the original collections to Poinsett. Abundant genetic variation likely offers raw material for improving the many shortcomings of cultivars, including vulnerability to cold, stem breakage, and pathogens such as Pythium and Phytophthora. However, genetic differences between populations make conservation of all of poinsettia's diversity difficult.
Assuntos
Euphorbia/genética , Jardinagem/história , Conservação dos Recursos Naturais , DNA de Plantas/genética , Ecossistema , Gliceraldeído-3-Fosfato Desidrogenases/genética , História do Século XIX , México , Filogeografia , Plastídeos/genética , Análise de Sequência de DNA , Clima TropicalRESUMO
Declining profitability of agriculture and/or higher prices of forest products and services typically drive an increase in forest cover. This article examines changes in forest cover in Candelaria Loxicha, Mexico. Forest cover increased in the area as a result of coffee cultivation in coffee forest-garden systems. Dependence on forest products and services, and not prices of forest products, drive the process in our study site. Low international coffee prices and high labor demand outside the community might pull farmers out of agriculture, but they do not completely abandon the lands. A diversification in income sources prevents land abandonment and contributes to maintaining rural populations and coffee forest gardens.
Assuntos
Agricultura , Café , Conservação dos Recursos Naturais , Economia , Agricultura Florestal , Agricultura/economia , Agricultura/educação , Agricultura/história , Coffea , Café/economia , Café/história , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/história , Conservação dos Recursos Naturais/legislação & jurisprudência , Produtos Agrícolas/economia , Produtos Agrícolas/história , Economia/história , Economia/legislação & jurisprudência , Meio Ambiente , Agricultura Florestal/economia , Agricultura Florestal/educação , Agricultura Florestal/história , Agricultura Florestal/legislação & jurisprudência , Jardinagem/economia , Jardinagem/educação , Jardinagem/história , História do Século XX , História do Século XXI , México/etnologia , Saúde da População Rural/história , População Rural/história , ÁrvoresRESUMO
This is a reconstruction of the career of the Most Reverend Dom Frei Cipriano de São José and the historical garden he built for his palace in Mariana, Minas Gerais, in the late eighteenth and early nineteenth centuries. The grounds, which, like most of their counterparts in Minas Gerais, contained an orchard and kitchen garden, underwent a major reform to fit the mold of the classical European garden. Orderly and showing aesthetic concern, they were an admirable space at the end of the colonial period, representing as they did the enlightened metropolitan elite's growing interest in natural history and botany. A variety of documental sources were used to reconstruct the history of the grounds and the career of the person behind their design, the enlightened Dom Frei Cipriano de São José.