Examinando por Autor "Weber, John C."

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A multiple-species participatory domestication programme in the Peruvian Amazon: experiences and results to date
(2005-01) Cornelius, J.; Sotelo Montes, C.; Ugarte Guerra, Julio; Weber, John C.; Ricse Tembladera, Auberto
In 1995, the World Agroforestry Centre (ICRAF) and partners initiated a participatory agroforestry domestication programme in the Aguaytía Watershed and Alto Amazonas province of the Peruvian Amazon. The programme, aimed primarily at conservation-through-use of genetic diversity, began with formal, participatory prioritization, leading to selection of four species: bolaina blanca (Guazuma crinita Martius: Sterculiaceae),capirona (Calycophyllum spruceanum (Bentham) Hooker f. Ex Schumann)), guaba (Inga edulis C. Martius: Leguminosae (Mimosoideae)), peach palm (Bactris gasipaes Kunth: Palmae). Open-pollinated seed of each was collected from farmer-selected mother trees, and used in the establishment of a series of seedling seed orchards / progeny tests, the individual blocks of which were dispersed on lands of individual collaborating farmers. Almost ten years later these trials are beginning to produce seed, the Aguaytían famers have organized themselves into a wood and seed producers’ cooperative, the technology developed is being adopted more widely, and genetic results are becoming available. We describe the programme and its results in detail, with special emphasis on its innovative features. Subsequently, we evaluate success to date in relation both to initial objectives and the programme’s response to the evolving local forestry and development environment. Finally, we consider future priorities.
El balance entre la ganancia genética y la conservación en un programa de mejoramiento participativo: el caso del pijuayo (Bactris gasipaes kunth)
(Academic Publishers, 2006-01-31) Cornelius, J.; Clement, C.; Weber, John C.; Sotelo Montes, C.; Van Leeuwen, J.; Ugarte Guerra, Julio; Ricse Tembladera, Auberto; Arévalo López, L.
[ES] Encontrar un equilibrio entre la conservación de recursos genéticos y el mejoramiento genético puede ser difícil. El problema se explora en el presente artículo, en parte a través de un estudio de caso de un programa de mejoramiento genético participativo de pijuayo (Bactris gasipaes Kunth, Palmae), conducido en la Amazonía peruana por el Centro Mundial de Agroforestería (ICRAF) y el Instituto Nacional de Investigación Agraria del Perú (INIA). El pijuayo, que fue originalmente domesticado por los amerindios, produce un rango de materiales y productos comercializables, sin embargo, hoy, los frutos y los cogollos (palmito) constituyen los principales productos. Se describen las características de los clientes (agricultores pequeños de subsistencia y empresas con plantaciones agro-industriales) para estos productos y aquellos del proyecto ICRAF – INIA y se explora el impacto sobre la diversidad genética de futuras opciones de manejo. Sigue a esto una amplia discusión de las relaciones entre la ganancia genética y el mantenimiento de la diversidad genética para el mejoramiento y sus implicaciones. El programa ICRAF – INIA fue diseñado para enfatizar la conservación genética y la puntual distribución de germoplasma en vez de la ganancia genética. El análisis presentado aquí sugiere que con manejo cuidadoso la diversidad genética se puede conservar efectivamente a los largo de 20 generaciones de mejoramiento. No obstante, existe un conflicto fundamental entre la ganancia genética y la conservación genética. Consecuentemente, ningún programa de mejoramiento puede conservar toda la diversidad genética de procedencias locales (landrace) o especies y deben desarrollarse estrategias de manejo de recursos genéticos para resolver estos conflictos a través de decisiones informadas y explícitas. Se presentan algunas de tales estrategias correspondientes a diferentes niveles de énfasis o ganancia versus diversidad.--- [EN] Finding an equilibrium between genetic resources conservation and genetic improvement can be difficult. The problem is explored in this paper, partly through a case study of a participatory improvement programme of peach palm (Bactris gasipaes Kunth, Palmae), implemented in the Peruvian Amazon by the World Agroforestry Centre (ICRAF) and the Peruvian National Institute for Agricultural Research and Extension (INIEA). Peach palm, which was originally domesticated by Amerindians, produces a range of useful substance and marketable products, but today the fruit and heart-of-palm are the principal products. The characteristics of the clients (subsistence smallholders and agro-industrial plantation companies) for these crops and those of the ICRAF-INIEA project are described, and the impact on genetic diversity of future management options is explored. This is followed by a wider discussion of the relationships between genetic gain and maintenance of genetic diversity for improvement, and their implications. The ICRAF-INIEA programme was designed to emphasize genetic conservation and timely germplasm delivery rather than genetic gain. The analysis presented here suggests that, with careful management, genetic diversity can be effectively conserved through 20 generations of improvement. Nevertheless, there is a fundamental conflict between genetic gain and genetic conservation. Consequently, no improvement programme can conserve all of the genetic diversity of a landrace or species and genetic resource management strategies must be developed to resolve these conflicts through explicit and informed decisions. Some such strategies, corresponding to different levels of emphasis on gain versus diversity, are presented.
Participatory domestication of agroforestry trees: An example from the Peruvian Amazon
(Taylor and Francis Group, 2001-08-01) Sotelo Montes, Carmen; Vidaurre Arévalo, Héctor; Weber, John C.; Simons, Anthony; Dawson, Ian
Valuable tree genetic resources are declining around many farming communities in the Peruvian Amazon, limiting farmers' options for economic development. The International Centre for Research in Agroforestry is working with farming communities to increase productivity and long-term sustainability of their forests, and to empower them to conserve tree genetic resources. This paper describes some principles of participatory tree domestication, and how researchers are working with farmers to select improved planting materials, reduce the risk of poor tree adaptation, produce and deliver high-quality planting material, and scale up participatory tree domestication.
Preliminary Evidence for Domestication Effects on the Genetic Diversity of Guazuma crinita in the Peruvian Amazon
(MPDI, 2020-07-23) Tuisima Coral, Lady Laura; Hlásná Čepková, Petra; Weber, John C.; Lojka, Bohdan
Guazuma crinita, a fast-growing timber tree species, was chosen for domestication in the Peruvian Amazon because it can be harvested at an early age and it contributes to the livelihood of local farmers. Although it is in an early stage of domestication, we do not know the impact of the domestication process on its genetic resources. Amplified fragment length polymorphic (AFLP) fingerprints were used to estimate the genetic diversity of G. crinita populations in different stages of domestication. Our objectives were (i) to estimate the level of genetic diversity in G. crinita using AFLP markers, (ii) to describe how the genetic diversity is distributed within and among populations and provenances, and (iii) to assess the genetic diversity in naturally regenerated, cultivated and semi-domesticated populations. We generated fingerprints for 58 leaf samples representing eight provenances and the three population types. We used seven selective primer combinations. A total of 171 fragments were amplified with 99.4% polymorphism at the species level. Nei’s genetic diversity and Shannon information index were slightly higher in the naturally regenerated population than in the cultivated and semi-domesticated populations (He = 0.10, 0.09 and 0.09; I = 0.19, 0.15 and 0.16, respectively). The analysis of molecular variation showed higher genetic diversity within rather than among provenances (84% and 4%, respectively). Cluster analysis (unweighted pair group method with arithmetic mean) and principal coordinate analysis did not show correspondence between genetic and geographic distance. There was significant genetic differentiation among population types (Fst = 0.12 at p < 0.001). The sample size was small, so the results are considered as preliminary, pending further research with larger sample sizes. Nevertheless, these results suggest that domestication has a slight but significant effect on the diversity levels of G. crinita and this should be considered when planning a domestication program.