Genetic Diversity of Darnel (Lolium Temulentum L.) in Malo, Ethiopia Depends on Traditional Farming Systems

ABSTRACT: In the present study, we investigated the influence of social and environmental factors in the genetic diversity of tomato landraces in the South-Central region of Mexico. A total of 30 tomato landraces, collected in 18 villages with different ethnolinguistic affiliations, were analyzed. We reported that the genetic diversity of tomato landraces is associated with the ethnolinguistic group, weather, and soil-type present in the region studied. Our results showed that there are morphological differences between landraces grown by different ethnolinguistic groups; however, there was also evidence of morphological similarities between landraces from groups with different ethnolinguistic affiliations. Finally, different selection criteria, mainly fruit color, size and shape, plays an important role in the phenotypic divergence among landraces grown in different traditional farming systems.

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Defining and identifying crop landraces

Plant Genetic Resources ◽

10.1079/pgr200591 ◽

2005 ◽

Vol 3 (3) ◽

pp. 373-384 ◽

Cited By ~ 195

Author(s):

Tania Carolina Camacho Villa ◽

Nigel Maxted ◽

Maria Scholten ◽

Brian Ford-Lloyd

Keyword(s):

Genetic Diversity ◽

Crop Improvement ◽

Farming Systems ◽

Traditional Farming ◽

Crop Species ◽

High Genetic Diversity ◽

Working Definition ◽

Landrace Diversity ◽

Cultivated Plant ◽

Historical Origin

Awareness of the need for biodiversity conservation is now universally accepted, but most often recent conservation activities have focused on wild species. Crop species and the diversity between and within them has significant socioeconomic as well as heritage value. The bulk of genetic diversity in domesticated species is located in traditional varieties maintained by traditional farming systems. These traditional varieties, commonly referred to as landraces, are severely threatened by genetic extinction primarily due to their replacement by modern genetically uniform varieties. The conservation of landrace diversity has been hindered in part by the lack of an accepted definition to define the entity universally recognized as landraces. Without a definition it would be impossible to prepare an inventory and without an inventory changes in landrace constituency could not be recognized over time. Therefore, based on a literature review, workshop discussion and interviews with key informants, common characteristics of landraces were identified, such as: historical origin, high genetic diversity, local genetic adaptation, recognizable identity, lack of formal genetic improvement, and whether associated with traditional farming systems. However, although these characteristics are commonly present they are not always all present for any individual landrace; several crop-specific exceptions were noted relating to crop propagation method (sexual or asexual), breeding system (self-fertilized or cross-fertilized species), length of formal crop improvement, seed management (selection or random propagation) and use. This paper discusses the characteristics that generally constitute a landrace, reviews the exceptions to these characteristics and provides a working definition of a landrace. The working definition proposed is as follows: ‘a landrace is a dynamic population(s) of a cultivated plant that has historical origin, distinct identity and lacks formal crop improvement, as well as often being genetically diverse, locally adapted and associated with traditional farming systems’.

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Yam: a neglected and underutilized crop in Brazil

Horticultura Brasileira ◽

10.1590/s0102-05362011000100003 ◽

2011 ◽

Vol 29 (1) ◽

pp. 16-20 ◽

Cited By ~ 8

Author(s):

MVBM Siqueira

Keyword(s):

Cropping Systems ◽

Farming Systems ◽

Traditional Farming ◽

Local Varieties ◽

Adequate Information ◽

Brazil Current ◽

Underutilized Crop ◽

Dioscorea Species ◽

Colonization Period ◽

Traditional Communities

In Brazil current studies and investments on yams are incipient. Similarly, the literature in recent decades lacks adequate information on this group of plants. The existing literature, on its turn, requires more than ever to be revised and organized. Yams have joined the so-called "neglected" group of crops for several reasons, but particularly because they are associated with poor and traditional communities. Many vegetables introduced in Brazil during the colonization period have adapted to different cropping systems, yams being an excellent example. This diversity resulted very widespread, yet poorly recognized in the country. In turn, the gardens using traditional farming systems continue to maintain and enhance yam local varieties. Studies from other countries, with an emphasis on characterization and genetic breeding, brought to light an urgent need for Brazil to invest in yams as a food rich in carbohydrates, even to the point of alterations in food public policy. Reversal of the yam's current stigma is both a challenge to the scientific community and to the population as a whole. This paper aims to raise pertinent questions about Dioscorea species, an important key group for many communities in tropical countries, yet still unrecognized as so in Brazil.

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Genetic variation in native and farmed populations of Tambaqui (Colossoma macropomum) in the Brazilian Amazon: regional discrepancies in farming systems

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-376520130007 ◽

2013 ◽

Vol 85 (4) ◽

pp. 1439-1447 ◽

Cited By ~ 8

Author(s):

Jonas Aguiar ◽

Horacio Schneider ◽

Fatima Gomes ◽

Jeferson Carneiro ◽

Simoni Santos ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Dna Sequences ◽

Amazon Basin ◽

Farming Systems ◽

Wild Populations ◽

The West ◽

Colossoma Macropomum ◽

Breeding Stock ◽

History Of

The tambaqui, Colossoma macropomum, is the most popular fish species used for aquaculture in Brazil but there is no study comparing genetic variation among native and farmed populations of this species. In the present study, we analyzed DNA sequences of the mitochondrial DNA to evaluate the genetic diversity among two wild populations, a fry-producing breeding stock, and a sample of fish farm stocks, all from the region of Santarém, in the west of the Brazilian state of Pará. Similar levels of genetic diversity were found in all the samples and surprisingly the breeding stock showed expressive representation of the genetic diversity registered on wild populations. These results contrast considerably with those of the previous study of farmed stocks in the states of Amapá, Pará, Piauí, and Rondônia, which recorded only two haplotypes, indicating a long history of endogamy in the breeding stocks used to produce fry. The results of the two studies show two distinct scenarios of tambaqui farming in the Amazon basin, which must be better evaluated in order to guarantee the successful expansion of this activity in the region, and the rest of Brazil, given that the tambaqui and its hybrids are now farmed throughout the country.

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Research Concerning Cucumber (Cucumis Sativus L. Mill) Genetic Diversity

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Agriculture ◽

10.15835/buasvmcn-agr:6531 ◽

2011 ◽

Vol 68 (2) ◽

Author(s):

Aurel MAXIM ◽

Mignon ŞANDOR ◽

Lucia MIHALESCU ◽

Ovidiu MAXIM ◽

Oana MARE ROŞCA

Keyword(s):

Genetic Diversity ◽

Biological Diversity ◽

Genetic Erosion ◽

Farming Systems ◽

Convention On Biological Diversity ◽

Cultivated Plants ◽

Cucumis Sativus L ◽

Local Varieties ◽

Industrial Farming ◽

The University

During the second part of the twentieth century the cultivated plants have been faced with genetic erosion, because of the expandinding industrial farming systems. The sustainable agriculture can not exist without a rich genetic diversity. After the United Nations Conference from Rio de Janeiro (1992), when the Convention on Biological Diversity was adopted, a series of acts and european references that protect agrobiodiversity had emerged. Between 2007 and 2010, at the University of Agricultural Sciences and Veterinary Medicine a program which aims to identify and conserve local vegetable varieties was conducted. Out of 290 cultivars, 171 (58.9%) were genuine local varieties. There were collected 12 cucumber cultivars from the following counties: Salaj (7), Cluj (3), Bistrita-Nasaud (1) and Satu-Mare (1). The morphologic caractheristics proved that all this 12 cultivars were authentic and valuable local varieties. The local varieties were agronomical, biological and biochemical characterized, both in field and laboratory. The seeds achieved from those 12 local varieties were preserved in the Suceava Gene Bank, from where stakeholders (farmers, agronomists, researchers) can obtain seeds.

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Traditional farming systems in south-eastern Turkey: the imperative of in situ conservation of endangered wild annual Cicer species.

Crop wild relative conservation and use ◽

10.1079/9781845930998.0243 ◽

2009 ◽

pp. 243-248

Author(s):

S. Abbo ◽

C. Can ◽

S. Lev-Yadun ◽

M. Ozaslan

Keyword(s):

In Situ Conservation ◽

Farming Systems ◽

Traditional Farming ◽

South Eastern ◽

Eastern Turkey ◽

Cicer Species

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Abundance and distribution of Ixodid tick species infesting cattle reared under traditional farming systems in Tanzania

African Journal of Agricultural Research ◽

10.5897/ajar2016.12028 ◽

2017 ◽

Vol 12 (4) ◽

pp. 286-299 ◽

Cited By ~ 6

Author(s):

Ibrahim Kerario Isack ◽

Muleya Walter ◽

Chenyambuga Sebastian ◽

Koski Marja ◽

Hwang Seong-Gu ◽

...

Keyword(s):

Tick Species ◽

Farming Systems ◽

Ixodid Tick ◽

Traditional Farming ◽

Abundance And Distribution

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Genomics of sorghum local adaptation to a parasitic plant

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1908707117 ◽

2020 ◽

Vol 117 (8) ◽

pp. 4243-4251 ◽

Cited By ~ 3

Author(s):

Emily S. Bellis ◽

Elizabeth A. Kelly ◽

Claire M. Lorts ◽

Huirong Gao ◽

Victoria L. DeLeo ◽

...

Keyword(s):

Genetic Diversity ◽

Local Adaptation ◽

Species Interactions ◽

Balancing Selection ◽

Control Plant ◽

Farming Systems ◽

Striga Hermonthica ◽

Loss Of Function ◽

Trade Offs ◽

Genome Wide

Host–parasite coevolution can maintain high levels of genetic diversity in traits involved in species interactions. In many systems, host traits exploited by parasites are constrained by use in other functions, leading to complex selective pressures across space and time. Here, we study genome-wide variation in the staple crop Sorghum bicolor (L.) Moench and its association with the parasitic weed Striga hermonthica (Delile) Benth., a major constraint to food security in Africa. We hypothesize that geographic selection mosaics across gradients of parasite occurrence maintain genetic diversity in sorghum landrace resistance. Suggesting a role in local adaptation to parasite pressure, multiple independent loss-of-function alleles at sorghum LOW GERMINATION STIMULANT 1 (LGS1) are broadly distributed among African landraces and geographically associated with S. hermonthica occurrence. However, low frequency of these alleles within S. hermonthica-prone regions and their absence elsewhere implicate potential trade-offs restricting their fixation. LGS1 is thought to cause resistance by changing stereochemistry of strigolactones, hormones that control plant architecture and below-ground signaling to mycorrhizae and are required to stimulate parasite germination. Consistent with trade-offs, we find signatures of balancing selection surrounding LGS1 and other candidates from analysis of genome-wide associations with parasite distribution. Experiments with CRISPR–Cas9-edited sorghum further indicate that the benefit of LGS1-mediated resistance strongly depends on parasite genotype and abiotic environment and comes at the cost of reduced photosystem gene expression. Our study demonstrates long-term maintenance of diversity in host resistance genes across smallholder agroecosystems, providing a valuable comparison to both industrial farming systems and natural communities.

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