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1.
Proc Natl Acad Sci U S A ; 115(3): E546-E554, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29295926

RESUMO

We examined how traditional farmers preserve the genetic diversity of a local common carp (Cyprinus carpio), which is locally referred to as "paddy field carp" (PF-carp), in a "globally important agricultural heritage system" (GIAHS), i.e., the 1,200-y-old rice-fish coculture system in Zhejiang Province, China. Our molecular and morphological analysis showed that the PF-carp has changed into a distinct local population with higher genetic diversity and diverse color types. Within this GIAHS region, PF-carps exist as a continuous metapopulation, although three genetic groups could be identified by microsatellite markers. Thousands of small farmer households interdependently obtained fry and parental carps for their own rice-fish production, resulting in a high gene flow and large numbers of parent carps distributing in a mosaic pattern in the region. Landscape genetic analysis indicated that farmers' connectivity was one of the major factors that shaped this genetic pattern. Population viability analysis further revealed that the numbers of these interconnected small farmer households and their connection intensity affect the carps' inherent genetic diversity. The practice of mixed culturing of carps with diverse color types helped to preserve a wide range of genetic resources in the paddy field. This widespread traditional practice increases fish yield and resource use, which, in return, encourages famers to continue their practice of selecting and conserving diverse color types of PF-carp. Our results suggested that traditional farmers secure the genetic diversity of PF-carp and its viability over generations in this region through interdependently incubating and mixed-culturing practices within the rice-fish system.


Assuntos
Agricultura/métodos , Carpas/genética , Variação Genética , Animais , China , Repetições de Microssatélites , Oryza/fisiologia , Filogenia
2.
J Environ Manage ; 280: 111714, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33303249

RESUMO

Human decisions, policies, and management strategies play an important role in structuring landscape patterns in a metropolitan area. Land-use/land-cover (LULC) changes can be considered probably the most important factor affecting the environment and the maintenance of landscape service flow. In particular, processes such as agricultural intensification, deforestation, urbanization and industrialization affect landscape heterogeneity in terms of composition and configuration. However, the multifunctional aspect of LULC as well as traditional agricultural practices can contribute to the maintenance of landscape service flow. This research aims to analyze and assess: (1) LULC dynamics and change from 1988 to 2019 within the metropolitan area of Córdoba (Argentina); (2) the effect of this change on landscape composition and configuration; (3) the flow of landscape services from 1988 to 2019, with the identification of hot-spots of landscape service provision. To analyze LULC dynamics and change within the study area, three Landsat images were utilized, while change detection analysis has been performed to identify the areas most affected by changes, the spatial distribution of change and the change trajectories of LULC classes in terms of landscape composition and configuration. Finally, the valuation of landscape service flow has been carried out by placing an economic value on the LULC classes, through the use of proxies. LULC pattern change has resulted in the expansion of extensive agriculture. The total variation from 1988 to 2019 has highlighted a significant reduction of Horticulture, Forests, and Grasslands, which have been converted into other classes (Urban and Extensive Agriculture). This conversion of LULC classes has had profound effects on landscape service flow, which guarantees the well-being of local communities. This research has contributed to the knowledge of where the hot-spots of landscape service' provision are located by helping landscape managers to identify suitable local policies able to preserve them, thus avoiding their loss, and enhancing landscape integrity, functionality, and resilience.


Assuntos
Monitoramento Ambiental , Urbanização , Agricultura , Argentina , Conservação dos Recursos Naturais , Florestas , Humanos
3.
Front Nutr ; 11: 1401715, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933886

RESUMO

The aim of this study was to analyze the impact of sociodemographic characteristics on willingness to try (WTT), regularly eat (WTE), or pay (WTP) for artificial meat, its expected societal challenges and general acceptance as well as its future potential development in Germany. Answers to an online questionnaire by 3,558 potential German adult consumers were evaluated. About 63% of the respondents thought this novel food was promising/acceptable. The vast majority (70%) stated that they would be willing to try it, with the most important drivers being ethics, curiosity and eco-friendliness. Around 57% of the participants said they would be willing to eat artificial meat regularly. Most of the respondents (40%) were willing to pay the same price for artificial as for conventional meat. In terms of its future potential, almost 75% of respondents believed that this new product would become commercialized in more than five years and that it was perceived as a solution that is both more ethical (67%) and more environmentally friendly (58%) than traditional meat. In addition, there were significant impacts of demographic factors on the willingness to engage with artificial meat. For example, high WTT and WTE were found among young male respondents (18-30 years of age), males that rarely consumed meat or had a low income (< €1,500). This also applied to the female respondents, who, however, belonged to higher income classes. Young German consumers with a high level of education or income up to €3,000 as well as consumers who did not eat meat had a high WTP for this novel food. In addition, respondents' positive opinion and acceptance of artificial meat had a positive influence on WTT and WTP. These results are important for the discussion of a paradigm shift in global meat production with respect to sustainability, demand for meat and the adoption of new food products.

4.
Waste Biomass Valorization ; 14(7): 2151-2166, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36540722

RESUMO

Purpose: Economic development of India mainly depends on agricultural sectors. The Indian traditional agricultural system is mainly based on chemical fertilizer to get better yield. The main motto of this research work is to change the traditional faith of Indian farmers and rural Indian economy. Methods: Bioprocessing of feather prepared from an efficient newly isolated bacterial strain, identified as Bacillus wiedmanni SAB10 is used to produce a nitrogen rich liquid fertilizer. The cell-free hydrolysate was prepared from submerged fermentation of poultry litter (1.25%, w/v) as sole media with supplemented as chicken feather (1%, w/v) in 79.41 h with pH 10.6. Results: Fermented hydrolysate contains a significant quantity of total amino acid (503.02 mg/L) with diversity (Cystine, Phenylalanine, Tyrosine, lysine, Valine, Proline and Alanine), total oligopeptides (4.65 mg/ml) and thiol content (58.09 µg/ml) which influence growth and yield (1.02 fold) of moong beans (Vigna radiata) plant in pot trials and as well as successfully scale up in field trials by the farmers. This liquid fertilizer not only makes plant healthy and has drought tolerance (proline content- 0.023 mg/g) capacity but also increases the grain quality by spraying the fertilizer on foliage with a ratio of 2:1 (Water: Feather hydrolysate) for two times (before the 1st flash and 2nd flash of flowering). Conclusion: Fermented feather hydrolysate is used full as a foliage fertilizer for the cultivation of moong beans. Some commercial properties and its eco-friendly, cost-effectiveness will make it a smart liquid fertilizer in near future. Supplementary Information: The online version contains supplementary material available at 10.1007/s12649-022-01982-9.

5.
J Ethnobiol Ethnomed ; 19(1): 39, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37710240

RESUMO

BACKGROUND: Agri-silvicultures (ASC) are biocultural practices procuring either the maintenance of wild diversity in predominantly agricultural spaces or introducing agrobiodiversity into forests. In the Mesoamerican region, ASC contribute to food sovereignty and territorial conservation and provide strategies for dealing with global changes. Previous inventories of ASC identified gaps in information about these systems in the Mexican Arid America region. This article raises the general question: How have human interactions between cultural, wild, and domesticated biodiversity in this territory? The particular questions in this paper are: (i) How have historical processes shaped human interactions between wild and domesticated biodiversity in the region? and (ii) What types of agri-silvicultures have emerged in Mexican Arid America since these relationships? METHODS: We trace a methodological border where archaeologists have identified the Mesoamerican region to define our study area as Arid America northern of this line in Mexico. We analyzed agriculturalization processes in Arid America through a historical review. Then, we carry out an inventory of Arid America ASC based on academic papers and other documented experiences. We constructed a spatial database and a typology to understand what kinds of agri-silviculture occur in the region. RESULTS: We identified several pre-Hispanic agri-silvicultural practices in the region, like hunting, fishing, terraces, gathering, and irrigation systems. The cultivation of native species of maize, beans, and squash even was registered. The Spanish colonization forced the agriculturization in arid northern Mexico, where itinerant hunting-gathering patterns predominated. In the twentieth century, the Green Revolution adopted this area as the principal setting for industrialized agriculture. The industrialized irrigated systems expansion and other political strategies provoked the simplification of productive landscapes. The practices that integrate wild and agricultural diversity systems were marginalized and invisibilized in such a context. Our research group proposes seven types of agri-silvicultural systems (natives agrisilvicultures, the oases agroforestry, Mesquite and Huisache ASC, homegardens and other traditional forms of agroforestry or agri-silvicultures). These agri-silvicultures provide food, medicine, fodder, and other contributions, as income to the families that practice them and protect native and exotic species. DISCUSSION AND CONCLUSION: The agriculturization of the arid environments initiated during Spanish colonization and the subsequent modernizing projects shaped dominant actors and ideologies in the arid north of Mexico. However, aridity has favored ancestral and agroecological relationships between cultures and biodiversity, emerging and subsisting Arid American agri-silvicultures. These agri-silvicultures deserve to be understood, adopted, and adapted to new contexts. They could be essential alternatives in the context of environmental changes.


Assuntos
Agricultura , Ração Animal , Humanos , Biodiversidade , Florestas , Povos Indígenas
6.
Heliyon ; 8(9): e10664, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36164510

RESUMO

This study aimed to characterise the floristic, structural composition of vegetation and soil status in the three land use types of protected area (PA), harvested woodland (HW) and traditional agriculture land (TA) in Salima District, Malawi. The HW and TA were further divided into categories based on the number of years the land was subjected to use as a disturbance i.e. into 1-5 years, 6-10 years, and 11+ years. Floristic data were collected on tree species, diameter at breast height (1.3 m from the ground) and regeneration categories of seedlings, saplings and poles. Soil samples were collected from the sampled plots where floristic data were collected. The study found 73 tree species from 58 genera and 31 families. High tree species diversity was recorded in HW used for over 11 years (p < 0.05). Tree species dominance depended on land use. Although the HW and TA showed an inverse J-shaped structure indicating stable tree populations, the HW had fewer big trees. The PA showed signs of ageing tree population shown by the bell-shaped structure. The study area was dominated by Sandy loam soils with very high porosity of above 40%. The more the years of disturbance, the higher the fertility loss within the TA in terms of organic matter and organic carbon but the reverse was true for nitrogen. The decrease in soil fertility loss was however, higher in TA as compared to HW and PA. To address the unstable structural status of some species in the land uses, deliberative silvicultural interventions should be introduced in the land uses. There is need to integrate fertility-improvement tree species and manure use in the agricultural land to improve soil fertility.

7.
J Ethnobiol Ethnomed ; 18(1): 30, 2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35392930

RESUMO

BACKGROUND: The Dong people mainly live in Hunan, Guangxi and Guizhou provinces, China, with a long history of glutinous rice cultivation, among which Kam Sweet Rice (KSR) is a group of rice landraces that has been domesticated for thousands of years by the Dong people. The core distribution area of KSR is Liping, Congjiang and Rongjiang County of southeast, Guizhou Province. Paddy fields, forests, livestock and cottages have formed a special artificial wetland ecosystem in local area, and the Dong people have also formed a set of traditional farming systems of KSR for variety breeding, field management, and soil and water conservation. However, this traditional agricultural management has not been reported at multiple levels based on landraces, species and ecosystems. METHODS: Fieldwork was conducted in ten villages in southeast Guizhou from 2019 to 2021. A total of 229 informants were interviewed from the villages. Semi-structured and key informant interviews were administered to collect ethnoecological data on the characteristics and traditional utilization of KSR, traditional farming systems and agricultural management of the Dong people. RESULTS: (1): A total of 57 KSR landraces were recorded as used by the Dong people in southeast Guizhou. We analyzed the cultural importance index (CII) of all KSRs. KSR with high CII often has a pleasant taste, special biological characteristics of cold resistance, disease and insect resistance and high utilization in the traditional culture of Dong people. (2) There is a clear division of labor between men and women in the breeding, seed retention, field management and grain storage management of different landraces of KSR in Dong communities. In order to resist natural disasters and insect pests, the cultivation of KSR is usually managed by multi-variety mixed planting. These agricultural management modes are the result of Dong people's understanding and adaptation to the local natural geographical environment, as well as the experience and wisdom crystallization of Dong people's long-term practice. (3) The traditional farmland of Dong People is a typical artificial wetland ecosystem that is planted with mixed KSR landraces with rich traditional wisdom. In addition, the economic benefit of the rice-fish-duck symbiotic system was 3.07 times that of hybrid rice alone; therefore, the rice-fish-duck system not only has the function of maintaining soil, water and ecological balance but also improves the income of Dong people. CONCLUSION: KSR is a special kind of rice that has been domesticated and cultivated by Dong people for thousands of years. Dong people have also formed traditional agriculture dominated by KSR cultivation. The traditional agricultural management of Dong people provides suitable habitats for flora and fauna with biodiversity protection, and convenient conditions for rational utilization and distribution of water resources were also provided. This traditional management mode is of great significance for environmental protection, climate change response, community resource management, sustainable utilization and agricultural transformation in modern society. Therefore, we call for interdisciplinary research in natural and social sciences, in-depth study of the ecological culture of ethnic areas, and sort out treasures conducive to the development of all mankind.


Assuntos
Oryza , Agricultura , Animais , Biodiversidade , China , Ecossistema , Feminino , Humanos , Melhoramento Vegetal , Solo , Paladar
8.
Front Public Health ; 10: 882943, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35615043

RESUMO

In the present age, the world agricultural heritage can inspire agroecology and sustainable agriculture. But various risks have threatened, eroded and forgotten this heritage, so dynamic conservation of this heritage is essential. In this study, "Qanat Irrigated Agricultural Heritage Systems, Kashan, Iran" which has been registered worldwide in the face of corona pandemic risks has been selected as a case study. In this qualitative research, in addition to field observations and documentary studies, 25 in-depth interviews and 39 semi-structured interviews with experts and key informants was done and grounded theory and content analysis have been used. In the process of interviews and analyzes based on "risk society theory", risks and wicked problems and related solutions have been identified and finally based on cultural theory, "clumsy solution space" has been summarized and presented for dynamic conservation. Based on the findings of this study, paying attention to a kind of reward for ecosystem services, developing online sales of agricultural products in rural areas of Kashan and also creating twinning with similar areas can help solve wicked problems. Also, paying more attention to the regulations for the protection of qanats, as well as the laws for home business insurance, can strengthen sustainable development in this rural area. Due to the wide range of different dimensions of agricultural heritage, it is suggested that in future research, clumsy solution spaces for each of these dimensions be created and developed separately.


Assuntos
COVID-19 , Ecossistema , Agricultura/métodos , COVID-19/epidemiologia , Humanos , Irã (Geográfico)/epidemiologia , Pandemias
9.
Front Plant Sci ; 10: 1161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31616452

RESUMO

Traditional crop varieties are an important source of genetic diversity for crop adaptation and modern breeding. Landraces of Asian (Oryza sativa) and African (Oryza glaberrima) rice have been well studied on the continents where they were domesticated. However, their history of cultivation in northern South America is poorly understood. Here, we reveal the rice diversity that is maintained by Maroons, descendants of enslaved Africans who fled to the interior forests of the Guianas ca. 300 years ago. We interviewed subsistence farmers who practice shifting cultivation along the Maroni and Lawa rivers that form the natural border between French Guiana and Suriname, and used ethnobotanical and morphological methods to identify around 50 varieties, of which 15 were previously undocumented. The genetic origin of these varieties was explored using the Angiosperms353 universal probe set. Despite the large distances between sites and relative inaccessibility of the area, phenotypic and genetic diversity did not display any geographic structure, which is consistent with knowledge of seed exchange among members of the same ethnolinguistic group. Although improved US cultivars were introduced in Maroon villages in the 1940s, these have not displaced the traditional landraces, which are cherished for their taste and nutritious qualities and for their importance in Maroon spiritual life. The unique agricultural and ritual practices of Maroons confirm their role as custodians of rice diversity, a role that is currently under threat from external pressures and encroaching globalization. We expect that the rice diversity uncovered in this study represents only a fraction of the total diversity in the Guianas and may constitute a large untapped resource that holds promise for future rice improvement. Further efforts to inventory and preserve these landraces will help to protect a precious cultural heritage and local food security.

10.
J Ethnobiol Ethnomed ; 12(1): 54, 2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27881142

RESUMO

BACKGROUND: Documenting the spectrum of ecosystem management, the roles of forestry and agricultural biodiversity, TEK, and human culture for food sovereignty, are all priority challenges for contemporary science and society. Ethnoagroforestry is a research approach that provides a theoretical framework integrating socio-ecological disciplines and TEK. We analyze in this study general types of Agroforestry Systems of México, in which peasants, small agriculturalist, and indigenous people are the main drivers of AFS and planning of landscape diversity use. We analyzed the actual and potential contribution of ethnoagroforestry for maintaining diversity of wild and domesticated plants and animals, ecosystems, and landscapes, hypothesizing that ethnoagroforestry management forms may be the basis for food sufficiency and sovereignty in Mexican communities, regions and the whole nation. METHODS: We conducted research and systematization of information on Mexican AFS, traditional agriculture, and topics related to food sovereignty from August 2011 to May 2015. We constructed the database Ethnoagroforestry based on information from our own studies, other databases, Mexican and international specialized journals in agroforestry and ethnoecology, catalogues and libraries of universities and research centers, online information, and unpublished theses. We analyzed through descriptive statistical approaches information on agroforestry systems of México including 148 reports on use of plants and 44 reports on use of animals. RESULTS: Maize, beans, squashes and chili peppers are staple Mesoamerican food and principal crops in ethnoagroforestry systems practiced by 21 cultural groups throughout Mexico (19 indigenous people) We recorded on average 121 ± 108 (SD) wild and domesticated plant species, 55 ± 27% (SD) of them being native species; 44 ± 23% of the plant species recorded provide food, some of them having also medicinal, firewood and fodder uses. A total of 684 animal species has been recorded (17 domestic and 667 wild species), mainly used as food (34%). CONCLUSIONS: Ethnoagroforestry an emergent research approach aspiring to establish bases for integrate forestry and agricultural diversity, soil, water, and cultural richness. Its main premise is that ethnoagroforestry may provide the bases for food sovereignty and sustainable ecosystem management.


Assuntos
Agricultura , Conservação dos Recursos Naturais , Ecossistema , Etnobotânica , Agricultura Florestal , Biodiversidade , México
11.
Ambio ; 44(8): 803-14, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25851484

RESUMO

Traditional agriculture benefits a rich diversity of plants and animals. The winter-flooded rice fields in the Qinling Mountains, China, are the last refuge for the endangered Asian crested ibis (Nipponia nippon), and intensive efforts have been made to protect this anthropogenic habitat. Analyses of multi-temporal satellite data indicate that winter-flooded rice fields have been continuously reduced across the current range of crested ibis during the past two decades. The rate of loss of these fields in the core-protected areas has unexpectedly increased to a higher level than that in non-protected areas in the past decade. The best fit (R (2) = 0.87) numerical response model of the crested ibis population shows that a reduction of winter-flooded rice fields decreases population growth and predicts that the population growth will be constrained by the decline of traditional winter-flooded rice fields in the coming decades. Our findings suggest that the decline of traditional rice farming is likely to continue to pose a threat to the long-term survival and recovery of the crested ibis population in China.


Assuntos
Agricultura , Aves/fisiologia , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Oryza , Animais , China , Ecossistema , Oryza/crescimento & desenvolvimento , Dinâmica Populacional
12.
Rev. peru. biol. (Impr.) ; 27(4): 509-516, Oct-Dec 2020. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1150089

RESUMO

Resumen En este trabajo se describe el modo de conservación in situ del sistema de producción y la diversidad fenotípica de papas nativas en los resguardos indígenas de la etnia de los Pastos. En el estudio se utilizaron dos metodologías: 1) una caracterización de los sistemas tradicionales de producción mediante investigación acción participativa en los resguardos indígenas de Males Córdoba y El Gran Cumbal y 2) una caracterización morfológica de las papas nativas mediante 26 descriptores cualitativos. Se encontró que el 16% de las familias cultivan al menos una variedad de papa nativa, distribuidas en zonas de subpáramo y páramos entre 2900 y 3500 m de altitud, en un agroecosistema de producción autóctono llamado "Shagra", con manejo tradicional de labranza mínima del suelo "Guachado" y áreas cultivadas inferiores a 600 m2. Se identificaron 38 variedades clasificadas en dos tipos, según los indígenas: chauchas y guatas, que representaron el 65 y el 35% respectivamente. Con el análisis de conglomerados se identificaron siete grupos discriminados por chauchas, guatas, lugar de procedencia y características morfológicas. Estas comunidades indígenas preservan el conocimiento ancestral y los recursos genéticos, cultivando una alta diversidad de papas nativas en asociación con cultivos andinos, lo que contribuye a la seguridad y soberanía alimentaria.


Abstract This paper describes the in situ conservation mode of the production system and phenotypic diversity of native potatoes in the indigenous reserves of the Los Pastos ethnic group. Two methodologies were used in the study: 1) a characterization of traditional production systems through participatory action research in the indigenous reservations of Males Córdoba and El Gran Cumbal, and 2) a morphological characterization of native potatoes through 26 qualitative descriptors. We found that 16% families cultivate at least one variety of native potato, distributed in sub-páramo and páramo areas between 2,900 and 3,500 m above sea level, in an autochthonous production agroecosystem named "Shagra", with traditional minimum soil tillage management ("Guachado") and cultivated areas less than 600 m2. Thirty eight varieties were identified and classified in two types, according to the indigenous people: chauchas and guatas, representing 65 and 35%, respectively. The cluster analysis identified seven groups, discriminated by chauchas, guatas, place of origin, and morphological characteristics. These indigenous communities preserve their traditional knowledge and genetic resources by growing a diversity of native potatoes in association with other Andean crops, which contributes to food security and sovereignty.

13.
Anc Sci Life ; 33(1): 60-70, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25161333

RESUMO

Plant propagation is critical to augment the resource and has been the main concern for farmers and planters through history. India has evolved the science of Vrksayurveda to address the above issue. An effort is made here to review Vrksayurveda literature related to nursery techniques. Different libraries were visited and relevant review material obtained by hand search and from databases. Interaction with Sanskrit scholars and eminent scientists working in the field of Vrksayurveda, as well as the efforts of the authors of this paper, helped in the selection of pertinent literature. In the absence of original texts, authentic translations of the publications were referred. A conscious decision was made to limit the search to the fields of seed storage, pretreatment and nutrition of seedlings. To have a comparative account recent trends and literature on nursery technology were also examined. This was supplemented by interviews with traditional organic farmers. Our survey revealed that the time period of the literature pertaining to Vrksayurveda ranges from BCE 1200 to the present times. The subject has evolved from morphological descriptions and uses of plants, in texts such as Rgveda and Atharvaveda, to treatises dedicated solely to the art of growing plants like Krsi-Parasara and Vrksayurveda. It is also evident that there were important periods when more works appeared across subjects such as water divining, soil types, seed collection and storage, propagation, germination and sprouting, watering regimen, pest, and disease control. The review revealed that valuable information pertaining to nursery techniques is available in Vrksayurveda, which can be used in the development of nursery protocol. This will not only help in effective organic nursery management, but also ensure the health and livelihood security of the communities involved and effective waste management.

14.
Genet. mol. biol ; 31(3): 725-733, 2008. graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-490062

RESUMO

We used simple sequence repeat (SSR) markers to investigate the genetic diversity of 78 sweet potato (Ipomoea batatas) accessions (58 landraces and 20 putative clones) from traditional agricultural households from 19 local communities in the Vale do Ribeira, São Paulo, Brazil. Eight SSR loci were assessed using 6 percent (w/v) polyacrylamide gels stained with silver nitrate and the accessions genotyped considering the presence or absence of bands. The results were subjected to analysis of molecular variance (AMOVA), and cluster and principal coordinate analyses. Spatial structure was assessed using Mantel's test to compare genetic and geographic distances. Each primer pair generated between three and ten clearly scorable polymorphic fragments. Cluster analyses showed a Jaccard's index from 0.3 to 1.0, indicating high genetic and intravarietal diversity. Accessions from all 19 communities were not spatially structured (r = 0.15, p < 0.054), with AMOVA indicating that most of the variability (58.2 percent) was distributed within households and only 18.1 percent of the variability was distributed between households within communities. The outcrossing mating system of sweet potato, and anthropic factors such as selection of different varieties and their maintenance within household small plots and home gardens, as well as an extensive exchange system between agriculturists, may all be contributing to these results.

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