Phaseolus genetic diversity maintained on-farm in central Italy

Thirty-one Phaseolus vulgaris L. and fivePhaseolus coccineus L. landraces reproduced on-farm werefound in central Italy. They were mostly grown by elderly farmers who usuallyselect for a certain type of seed. Different varieties are often grown in eachlocation and on each farm. They are maintained on-farm because of a local marketrequest for high quality products or because of sticking to traditional familyuse in cooking (21.2 and 75.8% of recorded cases, respectively). Three AFLPprimer combinations were used to assess genetic variation among collectedmaterials, a wild accession of P.vulgaris and commercial varieties of both species. Theyrevealed a quite high percentage of polymorphism (90.2% of polymorphic bands asan average). A wide genetic variation was observed among collected materials andeach accession showed a unique pattern of polymorphism. WithinP. vulgaris, landraces werediscriminated in two main subgroups, the former including the accessions fromthe Mediterranean area around the Lake Trasimeno and the latter includingaccessions from the humid Mediterranean area within the Appennine Mountains.These findings demonstrate the peculiar genetic identity of the landracesstudied also in relationship to human and environmental selection pressures.Possible on-farm conservation strategies are briefly discussed in relationshipto the information collected.     

On-farm conservation of 12 cereal crops among 15 ethnic groups in Yunnan (PR China)

Due to the rapid diffusion of improved crop varieties, fewer and fewer landraces are being grown by farmers. The on-farm conservation of crop landraces has been proposed as means of conserving potentially important crop germplasm as an alternative to its ex situ conservation in gene banks, but the effectiveness of this approach is unproven. Particular attention is currently focused on producers sited in remote regions. Here, we report the outcomes of a survey focusing on the conservation and utilization of landraces of corn, rice, wheat, barley, buckwheat, broomcorn sorghum, Job’s tears (coix), oats and finger, foxtail, broomcorn and barnyard millets grown by 15 ethnic groups from Yunnan province (China). Many local varieties are still in existence through their utilization on-farm. The varietal richness per village sampled was estimated to be 3.5 (maximum of 17), with rice and maize being the most heterogeneous, and glutinous sorghum and barnyard millet the least. Varietal richness was significantly and positively correlated with the number of villages surveyed, the number of families and the head of population. The choice of crops and varieties maintained varied between the ethnic groups, with the more westerly and north westerly situated villages conserving the most landraces. The number of crop species used was negatively correlated with per capita annual income, while the correlation coefficient between varietal richness and per capita annual income was less pronounced. The major factors determining the level of on-farm conservation were remoteness, fragmentation of the arable area and cultural needs. The data provide baseline information for the elaboration of optimal strategies for in situ conservation and utilization of crop germplasm in China.     

Diversity, distribution and management of yam landraces (Dioscorea spp.) in Southern Ethiopia

Yam (Dioscorea spp.) is widely grown in many parts of Ethiopia and plays a vital role in local subsistence. Nevertheless, its diversity has not been studied in detail. A survey covering 339 farm households and eight districts was conducted in the major yam growing regions of Southern Ethiopia to investigate the diversity and distribution of yam landraces using structured and semi-structured questionnaires. A total of 37 named landraces were recorded, with a range from one to six (mean 2.9) on individual farms. Farmers’ decisions regarding the number and type of landraces maintained was influenced by tolerance of the landraces to drought, their maturity time and market demand. Most landraces had limited abundance and distribution, and only a few dominant landraces were widely grown. There was also variation amongst districts with respect to diversity, distribution and abundance of the landraces found. In the majority of the localities surveyed, farmers reported a decreasing trend in the number of landraces maintained on individual farms and in the overall yam production. Besides, in those limited areas where yam production is expanding, farmers are increasingly relying on a few selected landraces that mature early. Findings of this study suggest that local farmers in Wolayita and Gamo-Gofa zones maintain considerable yam diversity that remains to be further explored for sustainable utilization and conservation of the available genetic resources.     

Farmers’ adoption of maize (Zea mays L.) hybrids and the persistence of landraces in Southwest China: implications for policy and breeding

This paper examines changes in the distribution of maize hybrids and landraces in the mountainous areas of southwest China over 1998–2008, farmers’ reasons for cultivar adoption and the implications for national policies in relation to seed production and breeding, based on baseline data and a survey conducted in Guangxi, Yunnan and Guizhou. The study traced the dynamic changes in the adoption of hybrids and landraces in farmers’ fields, explored how individual farmer’s choices can influence local landrace distribution, and investigated the space for conducive policy and innovative action for on-farm conservation of maize genetic resources. The research showed that although there is strong farmers’ interest in accessing modern maize hybrids, farmers also express strong reasons for maintaining at least some of the landraces that satisfy local agronomic context and social preferences. Farmers recognized that hybrids have a number of advantages but they also indicated some disadvantages of the current available hybrids e.g. with respect to seed quality, local adaptability, taste and cost of seeds, but also lack of information on the performances of the new hybrids. Based on farmers’ reasoning and experiences, the requirements have been identified for improving yield combined with local preferences (agronomic, cultural and socio-economic). The paper concludes by identifying options for how China might seek to develop resilient seed systems for smallholder farmers in poor areas, under changing climatical conditions and volatile markets. Participatory Plant Breeding is among the options considered for bringing farmers’ needs into conservation and breeding strategies for improving local adaptation.     

Market-based incentives for conserving diversity on farms: the case of rice landraces in Central Tarai,Nepal

Market-based incentives are one means of encouraging farmers to grow landraces that are also of social value, thereby contributing to the conservation of crop genetic diversity on farms – and in principle, the cheapest. This study uses a participatory, market systems approach supplemented by baseline data from an ongoing project to analyze markets for rice landraces and modern varieties in Nepal. Nepal is located in the area of origin and diversity for Asian rice. With the exception of traditional Basmati rice (which is of high aromatic quality), most rice landraces are traded through small-scale informal channels. Traders earn higher profits handling modern varieties than landraces, with the exception of Basmati, which competes with modern varieties. The superior consumption qualities of Basmati are valued in markets, but conserving these landraces may not have great social value. Furthermore, farmers who grow Basmati are clearly better off than those who do not. Findings raise questions about the role of market-based incentives for conserving landraces on farms, the costs entailed in establishing a structure to generate them, and about efficiency vs. equity considerations in the design of conservation programs.     

Collecting maize (<Emphasis Type="Italic">Zea mays</Emphasis> L. convar. <Emphasis Type="Italic">mays</Emphasis>) with potential technological ability for bread making in Portugal

The Portuguese maize bread (“broa”) manufactured from traditional maize landraces still plays an important economic and social role on Central and Northern rural communities of the country. However the traditional maize landraces agricultural systems are changing. Local maize landraces are in risk of disappearing because of the progressive adoption of hybrid varieties not suitable for bread production. These changes are contributing to a major loss of genetic diversity. An expedition took place in the Central region of Portugal (Beira Interior and Beira Litoral) with the purpose of collecting enduring maize landraces with technological ability for bread production and to access the possibility of establishing a participatory plant breeding and conservation program. A total of 51 different maize landraces and 175 other varieties of associated crops were collected. Maize landraces showed to maintain high diversity and potential for improvement. The production relayed on small farms with polycrop, quality oriented, sustainable systems. A participatory plant breeding and conservation program would be possible on this region with the proviso that local authorities would be involved. This program would allow a higher valuation of these maize populations, contributing to halt the current loss of these unique Portuguese maize landraces.     

Phenotypic diversity and evolution of farmer varieties of bread wheat on organic farms in Europe

The contribution of farmers to the creation and maintenance of genetic diversity is beginning to receive more recognition in developed countries. Although the use of landraces and historic varieties has largely disappeared in countries with industrialized agricultural systems and formal seed markets, certain varieties with particular cultural significance have been continuously cultivated by farmers and other varieties have been preserved ex situ in genebanks. Recently, associations of organic farmers have become involved in the conservation and use of landraces and historic varieties (called farmer varieties in this article) because these varieties possess agronomic and quality traits that they have not found in modern varieties. In this study, eight farmer varieties of bread wheat from Europe selected by participating farmers were evaluated in on-farm trials during 3 years of cultivation. Each variety was grown on each farm, and phenotypic changes in each variety were measured the third year in a replicated split-plot trial on each farm comparing the version of each variety the farmer had multiplied to a sample of each variety from the region of origin. All varieties, including the two modern pureline varieties used as checks, showed statistically significant phenotypic changes over 3 years of multiplication. However, the magnitude of these changes was moderate and did not call into question varietal identity or distinctness. In addition, some traits of putative agronomic and adaptive importance, such as grain weight per spike and thousand kernel weight, did not respond positively to natural selection (environmental conditions and management practices) which suggests the necessity of farmer selection to maintain and improve varietal performance.     

Arkansas Discovery Farms: documenting water quality benefits of on-farm conservation management and empowering farmers

Arkansas Discovery Farms (ADFs) are private farms that collaborate with on-farm research, verification, and demonstration of farming's impact on the environment. We have nine ADFs representing livestock (broiler poultry and pasture grazed beef and sheep) and row crop agriculture (corn, cotton, rice, soybean, and wheat), where we collect water use and water quality data as a function of conservation management, using autosamplers equipped with edge-of-field H-flumes or weir flow structures, which measure and collect surface runoff. On the poultry farms, we are monitoring nutrient and sediment runoff originating immediately near poultry houses due to concerns with spillage of litter during bird removal and house clean out, as well as dust from tunnel ventilation. On a nearby farm we are assessing the impact of rotational grazing on water quality, soil organic matter, and soil health metrics. On the row crop farms we are assessing the impacts of conservation tillage and cover crops on soybean–corn rotations and cotton on nutrient and sediment runoff and the benefits of water harvesting and reuse of water conservation and quality. The information in this paper while preliminary, demonstrates how a state-wide on-farm demonstration program operates. Elevated nutrient and sediment runoff from around poultry production areas are decreased three-fold by directing runoff into ponds or through grassed waterways. While conservation tillage and cover crops do decrease nutrient and sediment runoff, no significant difference between conventional and conservation operations is yet to be realized. Importantly, ADF empowers farmers to proactively address environmental concerns. This paper discusses the development, guidance, principals, and goals of ADF and contrasts this with other farm monitoring projects, where the sources of nutrient impairment are the subject of ongoing litigation. Monitoring in divisive and transparent situations presents unique challenges with data ownership and release of findings, which can hinder productive outcomes of such monitoring.     

A Suitable Site for in situ (On-farm) Management of Plant Diversity in Traditional Agroecosystems of Western Himalaya in Uttaranchal State: A Case Study

There is a growing realisation world over that the introduction of modern agriculture has to be supplemented with measures to conserve biodiversity in situ if yield gains are to be stabilized. Hence, there is a growing interest from agricultural development specialists and conservation biologists for understanding the socioeconomic factors determining the conservation of biodiversity in situ. The present study was conducted with the objective of understanding the in situ (on-farm) conservation of agrobiodiversity in traditional agroecosystems taking the Urgam valley in north-western Himalaya of India, as a case study. An inventory was made of traditional crops and wild economic species for subsistence, and the structure of forest resource base, traditional knowledge related to resource management and use. Institutional and scientific challenges for in situ (on-farm) management of crop diversity were studied and are discussed in this paper. Complementarity of in situ (on-farm) conservation with ex situ conservation together with crop improvement in such marginal areas are suggested.     

Inferring seed exchange between farmers from population genetic structure of barley landrace Arabi Aswad from Northern Syria

Apart from their significance in genetic conservation, barley landraces are still favoured by local farmers in low-input farming systems. They often perform more predictably under adverse conditions than modern cultivars due to local adaptation. Increased seed exchange between farmers may put adaptation of local populations of barley landraces at risk. Isozyme markers were used to investigate differentiation and infer gene flow between local populations of barley landrace Arabi Aswad in Northern Syria. Inferred gene flow decreased exponentially with geographic distance and may imply that seed exchange between farmers is limited to a regional scale and diminishes over longer distance. Gene flow seems to be a suitable index for estimating seed exchange in highly inbreeding crop species such as barley. In the future, improved mobility of farmers and extension work may facilitate seed exchange over longer distances, and consequently jeopardise preservation of locally adapted landraces in barley.     

Farmers' valuation and conservation of crop genetic resources

This paper focuses on the value of landraces (traditional and local crop varieties) to farmers in centers of agricultural diversity. Additional information on the factors contributing to the private value which farmers assign to landraces may help to identify a strategy for ensuring the conservation of the crop genetic resources (CGRs) which are embodied in landraces while at the same time minimizing the costs. Economic and ethnobotanical approaches for examining the value of landraces complement one another. A formal economic approach establishes a framework for quantitative analysis while ethnobotanical methods provide qualitative data for assessing the likelihood that particular farmers or farm sectors will maintain landraces. Our research synthesizes the two approaches in order to examine farmer selection of local wheat landraces in relation to that of modern varieties in three provinces in western Turkey. Multiple farmer concerns (e.g. yield, risk, quality), environmental heterogeneity, and missing markets contribute to the persistence of landraces. Household characteristics informing variety choice will also affect the household's perceptions of the importance and value of landraces.     

Distribution, abundance and risk of loss of sorghum landraces in four communities in North Shewa and South Welo, Ethiopia

Field survey data of sorghum landrace populations grown by traditional farmers in four adjacent communities in the Ethiopian Highlands are used to analyze and project the local risk of loss of individual landraces under three scenarios: wild population, traditional farming and agricultural modernization. The risk of loss in the wild population scenario is based on landscape ecology theory which evaluates total population size, spatial distribution and patch occupancy, with high values for each factor and the sum of the factors decreasing the risk. This wild population analysis forms the basis for comparison with the other scenarios. In the traditional farming scenario, the deliberate actions of farmers must be taken into account through the recognition that the farmers favour various traits of the sorghum for specific reasons – yield, taste, storability, etc. – and will balance plant numbers according to quantity and quality requirements. In the agricultural modernization scenario, which includes the introduction of high-yield varieties and the tendency toward monocultures and agricultural chemical use, the traits of the landraces that are most likely to be displaced are hypothesized, as are those of the landraces that are likely to be retained on the basis of cultural or other factors. It is planned to follow up this baseline study with a long-term time-series study of the same communities to assess the validity of our projections.     

Local Organizations Involved in the Conservation of Crop Genetic Resources: Conditions for their Emergence and Success in Ethiopia and Kenya

Local organizations comprising of farmers, local formal and informal institutions, and public conservators can potentially be relevant options to confront the challenges of conserving indigenous crop varieties in developing countries. Although property rights and market failure problems experienced in crop genetic resources (CGRs) are different from other natural resources such as forests, wildlife, etc., such local organizations, and contractual arrangements within them, can be very instrumental in enhancing on-farm conservation. However, empirical investigations of such local organizations in order to determine the dimensions of their feasibility have been scarce. Against this background, this paper analyzes interactions of stakeholders in these local organizations and then explores the conditions for their emergence and success. The paper discusses field cases of on-farm conservation of traditional cereals and pulses from Ethiopia and indigenous vegetables from Kenya. It points out that local organizations conserving CGRs can be classified into different categories of contractual arrangements depending on certain driving factors that influence interactions of stakeholders and devolvement of decision-making authority. The paper further argues that these driving factors, which include accessibility to markets, presence of collective action or self-organizational capacity and provision of relevant CGRs conservation policies, form some of the key conditions determining the success of the case study organizations. The paper concludes by outlining policy implications on the structuring of such local organizations and the importance of certain factors in facilitating their emergence and success.     

Diversity in Phenotypic Profiles in Landrace Populations of Vietnamese Rice: A Case Study of Agronomic Characters for Conserving Crop Genetic Diversity on Farm

Phenotypic variation of agronomic characters in aromatic rice (Oryza sativa L.) was analyzed in order to elucidate the genetic diversity of the populations of rice landraces. Thirteen populations in Namdinh province, in the Red River Delta of Vietnam, were studied in both of farmers fields and an experimental field. Only small differences were found in agronomic characters among the populations, including populations containing different varieties. Variations among the populations in the frequency distributions of several characters suggested different degrees of diversity among the populations even among populations with the same variety name. The phenotypic profiles of farmers fields were different from those in an experimental field suggesting the environmental differences between them. One variety cultivated in the Myloc district had different phenotypic characters from the other varieties in the Haihau district more clearly in the experimental field. Since the small phenotypic variation in each of farm might be due to the genetic drift and selection by the farmers, on farm conservation of the landraces of rice is considered to be under a force to decrease phenotypic diversity. The present study suggests that the targeting several farms with different phenotypic profiles contribute to the conservation of regional genetic diversity of the landraces of rice.     

Towards a methodology for on-farm conservation of plant genetic resources

The signing of the Convention on Biological Diversity at the ``Earth Summit' in 1992, its ratification and its subsequent entering into force have highlighted the need for an approach to biodiversity conservation that employs both ex situ and in situ techniques in a complementary manner. Though much research has focused on ex situ techniques, less progress has been made in developing methodologies for the conservation of genetic diversity in situ. The definition of in situ conservation used in the Convention on Biological Diversity encompasses two distinct processes: conservation of wild species in genetic reserves and of crops on-farm. Of these two, the latter, where the genetic diversity of crop land races is conserved within traditional farming systems, has been the less studied and remains less well understood. While there are still relatively few practical examples of on-farm genetic resources conservation, most genetic diversity of immediate and potential use to plant breeders is found among land races, and there is evidence that it is being rapidly eroded. This paper attempts to set on-farm conservation within the context of plant genetic resource conservation as a whole, to introduces a possible generalised model for the conservation of genetic diversity on-farm and to promote debate around the science of on-farm conservation.     

Diversity between some Ethiopian farmer's varieties of barley and within these varieties among seed sources

Barley is one of Ethiopia's major crops. Cultivation is mostly by traditional varieties that are chosen by farmers for their suitability for end-use or their adaptation to specific farming systems. A collection of 155 barley lines was grouped in 13 varieties, according to the name given by the farmers. The collection was evaluated for simple agronomic traits and resistance to barley scald disease. A large level of diversity was found, mainly between varieties, but also within varieties between farms from which the samples originated. In spite of a certain degree of overlapping, these traditional farmer's varieties showed coherence for the characters measured. Earlier maturing varieties were found to be more susceptible to scald, but a number of accessions combined earliness with scald resistance. It is suggested that the traditional variety name be included, next to the physical characters of the collection site, as a parameter to explain the degree of diversity in Ethiopian barley germplasm evaluation. The cultivated area of a number of traditional barley varieties is declining rapidly and special collection missions are needed to preserve this germplasm.     

Changes of<Emphasis Type="Italic"> Sorghum bicolor</Emphasis> landrace diversity and farmers’ selection criteria over space and time,Ethiopia

Temporal and spatial changes of sorghum landrace diversity and related factors in five farming communities in north Shewa and south Welo, between 1992/1993 and 2000/2001, were studied in order to ascertain the stability of a range of factors that support the maintenance of the crop genetic diversity. The same farmers were interviewed and the same sorghum fields were surveyed both times. Over the 8-year period: the total area planted to sorghum decreased drastically in all five farming communities and a large percentage of the farmers in the communities (Hayk, 69%; Borkena, 68%; Epheson, 51%; Merewa Adere, 72%; and Bati, 54%) decreased the field size planted to sorghum, because of population growth, land redistribution policy, seasonal changes, and stagger cropping followed by interspecies crop displacement; landrace richness increased significantly in Merewa and Borkena, but decreased significantly in Bati, Epheson and Hayk; and farmers’ selection criteria, the reasons for growing specific landraces, increased significantly (10 in 1992/1993 vs. 22 in 2000/2001). Significant differences in field size distribution occur among the five farming communities. In 2000/2001, 22 “generalist” landraces (grown widely across three or more communities), and 46 “specialist” landraces (niche specific, restricted to certain microhabitats in one or two communities) were found. Landrace gains and losses from the farms surveyed in individual communities over the period are demonstrated.     

Participatory landrace selection for on-farm conservation: An example from the Central Valleys of Oaxaca, Mexico

On-farm conservation is recognized as a key component of a comprehensive strategy to conserve crop genetic resources. A fundamental problem faced by any on-farm conservation project is the identification of crop populations on which efforts should be focused. This paper describes a method to identify a subset of landraces for further conservation efforts from a larger collection representing the diversity found in the Central Valleys of Oaxaca, Mexico. Mexico is a center of origin and diversity for maize (Zea mays L.). The 17 landraces selected from an initial collection of 152 satisfy two criteria. First, they represent the diversity present in the larger collection. Second, they appear to serve the interests of farmers in the region. Data for applying the method were elicited through participatory as well as conventional techniques. They incorporate the complementary perspectives of both men and women members of farm households, and of plant breeders and social scientists.     

A case study of seed exchange networks and gene flow for barley (Hordeum vulgare subsp. vulgare) in Morocco

Local patterns of seed regeneration and trade that occur outside the formal breeding sector (seed exchange networks) can have a strong influence on the genetic diversity and evolution of traditional crop varieties. Despite this, little is known about the extent to which seed exchange networks influence gene flow and genetic structure in traditional crop varieties. Here we study barley (Hordeum vulgare subsp. vulgare) in rural communes of Northern Morocco in 2008 and 2009. We quantified seed regeneration and exchange by farmers within the seed exchange network using structured interviews. Using SSR markers, we also quantified the neutral genetic diversity and structure of a complex of traditional varieties referred to as Beldi that is managed in this exchange network. The majority of farmers (>88 %) report cultivating Beldi. Most seeds of Beldi (70–90 %) are maintained on-farm, while the remainder of seeds are obtained from local markets within the commune. Beldi has high genetic diversity and there is weak but significant genetic structure between communes (F_ST = 0.031). From SSR marker data there is evidence of a high level of gene flow between communes not reported in interviews. Seeds purchased in local markets likely represent seeds from a larger geographic region, leading to lower genetic structure among communes than expected based on the reported level of on-farm seed regeneration and local sourcing of seed. We discuss the implications of this seed exchange network for the conservation of traditional barley varieties in the study region.     

Conservation in a changing world: <Emphasis Type="Italic">in situ</Emphasis> conservation of the giant maize of Jala

Using survey data from Jala, Mexico, this case-study evaluates in situ maize conservation of the variety ‘Jala’ (Zea mays L.). Though historically ‘Jala’ was the dominant variety grown in the valley of Jala, today less than 20% of farmers grow it on only 5% of the maize area. Younger growers of the ‘Jala’ variety specialize in it, growing relatively large amounts for niche markets. Older, diversified farmers grow small areas for household use and to compete in a local contest. Conservation of the ‘Jala’ variety has been heavily influenced by shifting ideal concepts of maize, as determined by market and consumption demands and by a contest designed to promote in situ conservation. The current move away from nationalized purchasing may favor ‘Jala’s’ continued conservation.