Diversity and distribution patterns of enset landraces in Sidama, Southern Ethiopia

Diversity and distribution of enset landraces (clones) were investigated in 300 randomly selected peasant households at ten different locations in the Sidama region of Ethiopia using presence-or-absence data. A total of 86 named landraces were recorded, making the region an area of remarkably high enset landrace diversity. A substantial fraction of the landraces had a restricted distribution range and low abundance while a number were moderately common with the remaining few being cosmopolitan. Regional distribution was positively correlated with local abundance, such that more widespread landraces were also typically more abundant (r = 0.78, p < .01). Landrace diversity was not evenly distributed throughout the region, the highest diversity being recorded in mountain areas (r = 0.71, p < .05). Farmers exchange planting materials extensively, resulting in a fairly high (up to 70%) coefficient of similarity among sites. Implications for the collection and conservation of enset genetic resources are discussed.     

Genetic diversity analysis of yams (Dioscorea spp.) cultivated in China using ISSR and SRAP markers

Yam (Dioscorea spp.) is widely cultivated in China and many landraces are maintained by local farmers. However, there is little information available about their diversity and species identity. In this study, inter simple sequence repeat (ISSR) and sequence related amplified polymorphism (SRAP) techniques were used to assess genetic diversity within 21 yam landraces from seven cultivated populations. We observed high level of polymorphism among these landraces, specifically, 95.3 % for ISSR and 93.5 % for SRAP. Analysis of molecular variance revealed a significantly greater variation among the four yam species (40.39 %) and their populations (35.78 %) than within the populations (23.83 %). The unweighted pair group method arithmetic averages clusters and principal component analysis for 21 landraces formed four well-separated groups containing landraces of each of the four species, namely, Dioscorea opposita Thunb., Dioscorea alata L., Dioscorea persimilis Prain et Burkill, and Dioscorea fordii Prain et Burkill. The ISSR and SRAP primers were highly discriminatory among the 21 landraces; all 21 landraces could be easily differentiated using these primers. The average mean of gene flow (Nm = 0.1081) estimated from high genetic differentiation (Gst = 0.8222) suggested that gene flow among the populations was relatively restricted. The lack of genetic diversity within individual yam species suggests that it is critical to develop long-term strategies for enhancing genetic diversity within various yam species.     

Genetic erosion of Ethiopian tetraploid wheat landraces in Eastern Shewa,Central Ethiopia

Ethiopia is a centre of diversity and hosts rich genetic resources of tetraploid wheats. Through time, the wheat materials were subject to genetic erosion. Closer investigation was made to assess the status of loss, and identify the possible causes by studying two districts from East Shewa. Information from primary and secondary sources was reviewed and analysed. Farmers identified 26 tetraploid wheat landraces (21 from Akaki and 17 from Ejere), which were once widely grown in the area. Of these, only six were currently available. Compared to the formerly available number of landraces, the loss of diversity in the study area was estimated to be 77%. In the Ejere locality, the loss was 100% before the launching of the on farm landrace conservation programme, and for Akaki it was 95%. Major factors that contributed to the loss include: (1) introduction and expansion of bread wheat varieties; (2) expansion of tef; (3) lack of a mechanism to re-supply seeds of tetraploid wheat landraces; (4) decline in size of landholdings; (5) changes in land use and cropping patterns; (6) lack of policy support; and (7) expansion of improved tetraploid wheat varieties. The lessons from this study underscore the importance of strengthening the local seed supply system as a prerequisite for sustaining on farm conservation of landraces. Moreover, it is necessary to initiate diversity studies focusing on the distribution and status of tetraploid wheat landraces across the country. Complementing these by molecular analyses is essential in order to assess the genetic distinctness of the landraces.     

Landraces in central Italy: where and why they are conserved and perspectives for their on-farm conservation

Four hundred and twenty-seven landraces belonging to different plant species (forages, cereals, pulses, garden crops and fruit trees) were found on-farm in central Italy during exploration and collecting missions carried out since 1981. Open field crops are mostly grown under modern agricultural techniques by relatively young farmers on quite large farms for Italian standards. Garden crops are mostly grown by elderly farmers, running small farms or home gardens and using traditional farming systems which include the use of mechanical tools for soil preparation and occasionally the use of chemical fertilisers. There is no unique situation in on-farm conservation and management in the investigated area: the main factors involved appear to be a fragmented habitat and the presence of relatively elderly farmers. Most landraces are directly used by farmers' families, but a part is sold at local and wider markets. The main reasons why these landraces have been maintained on-farm are: their resistance/good productivity under difficult or harsh climatic conditions, traditional reasons or organoleptic peculiarities, which make them highly valued and expensive on the local and city markets and/or simply because they are appreciated by the families. Three example cases of effective on-farm conservation are presented. Social problems seem to be the main cause of genetic erosion. Perspectives and constraints to on-farm conservation and management are briefly discussed.     

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.     

Farmers’ Perception and Genetic Erosion of Tetraploid Wheats Landraces in Ethiopia

Assessing genetic erosion has been suggested as the first priority in any major effort to arrest loss of genetic diversity. In Ethiopia, although it is generally accepted that significant amount of genetic erosion has occurred and is still occurring, there is little data on its amount and extent. Thus, this study is conducted to quantify the extent of genetic erosion in Ethiopian tetraploid wheat landraces and to identify major causes of genetic erosion. To this end, a field survey of 126 farmers, randomly selected over five districts in eastern, south-eastern and central highlands of Ethiopia during 2001/2002 and 2002/2003 main cropping seasons was undertaken. Questioner was used to collect primary data from farmers who are potentially rich sources of information on genetic erosion at the variety level. Additional data were collected through key informant interviewing. Moreover, resampling was made from Tulo, Chiro and Harar Zuriya districts in eastern Ethiopia. Analysis of history profiles from primary and secondary data indicated a reduction in the use of local varieties over years. Triticum polonicum and T. turgidum are becoming very localized, and therefore, they are under greater threat of extinction. Using the calculation scheme: gene erosion=100%−gene integrity, i.e., the still extant landraces, genetic erosion was calculated for the three different areas where resamplings were made. Genetic erosion of 100% was observed both in T. durum and T. dicoccon in Tulo district. Likewise, genetic erosion of 85.7, 100 and 77.8%, respectively, was calculated for T. durum, T. turgidum and T. dicoccon in Chiro district. In Harar Zuriya, a genetic erosion of 88.9% for T. durum and 100% both in T. turgidum and T. dicoccon was detected. Number of farmers growing landraces of tetraploid wheats drastically decreased in all surveyed areas in the past decades. Displacement of landraces by other crops was the prominent factor for ending landrace cultivation. Farmers’ preference to yield potential and cash crops subsequently reduced the chance of maintaining landraces. Institutional factors like access to credit and the extension advice have influenced farmers’ decision regarding cultivar choice. In all surveyed areas, the most important initial source of seed of improved wheat varieties is the seed credit from the Ministry of Agriculture which uses a ‘plant now, pay later’ scheme to promote the distribution of improved varieties and fertilizers. The problem of genetic erosion through inappropriate maintenance of ex situ collections was also recognized and discussed.     

Yam (Dioscorea ssp.) domestication by the Nago and Fon ethnic groups in Benin

Guinea yams (Dioscorea cayenensis-rotundata complex; D. rotundata Poir. and D. cayenensis Lam.) have been described as resulting from a process of domestication of wild yams of the section Enantiophyllum by African farmers. Although currently practised by few farmers, the process of yam domestication is still on-going in Benin. In order to document the practices used and the indigenous knowledge maintained by Nago and Fon farmers, 27 villages were surveyed. In total, 57 farmers domesticating yam were identified, and 68 yams newly domesticated (or in domestication) were collected. Fon and Nago farmers domesticate yam mainly to widen the genetic basis of the existing diversity or for simple curiosity. Among the three wild yams species (D. abyssinica Hochst. ex Kunth, D. praehensilis Benth. and D. burkilliana J. Miège) used, D. praehensilis is the most important and the most exploited. Tuber of the wild yams are collected either in the bush (most often near the village) or in the forests (far from the village) during hunting. The domestication process consists of bringing into cultivation selected individuals which go through intense vegetative multiplication and selection procedures (over a lengthy but variable period of time) that induce morphological and biochemical changes in the plant mainly at the tuber level. Individuals resulting from these manipulations were found to be, either similar or identical to known landraces or completely new based on both morphological and isozyme analysis. Because it leads to some new cultivars, this process of domestication has potential in yam breeding and appears to be a strategy that could be useful to breeders, while developing a methodology for participatory breeding of yam.     

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.     

Trade-offs between on-farm varietal diversity and highly client-oriented breeding — a case study of upland rice in India

On-farm varietal diversity is now highest in marginal agricultural environments because, unlike the case in more favourable areas, modern varieties have not been a sufficiently attractive option for farmers to replace their landraces. However, the continued survival of landraces on farm is dependent on the continuing failure of plant breeding to provide better alternatives. Highly client-oriented breeding can produce suitable modern varieties for areas that were dominated by landraces. We examine here the case of the adoption of two upland rice varieties in three states in eastern India, Jharkhand, West Bengal and Orissa, where our surveys had confirmed low adoption of modern varieties in the upland ecosystem. The two new upland varieties were readily accepted by farmers who rapidly adopted them on large proportions of their land. On-farm diversity is maintained by the need to trade-off among varieties but once a variety with overall superiority was found this incentive was removed. The new varieties from the client-oriented breeding did not have weaknesses that farmers had to trade-off against their landraces so they were more likely to replace them. They also replaced older modern varieties. Farmers had previously maintained them along with landraces because they had to trade-off the higher yield of Kalinga III against the more stable yield of landraces or the higher yield of Vandana against the higher gain quality of the landraces. Only mean count per household could be used to test the significance of the differences between individual years. In all states, this revealed a significant reduction in landrace diversity with the adopting farmers when the addition of the two new varieties was not considered. Trends across years for mean varietal count, total count and Shannon–Wiener index showed a significant decline in Orissa, irrespective of whether the two new varieties were included in the analysis or not. In Jharkhand there was a significant decline only for mean count when the new varieties were not included. In Orissa, it was possible to test if rare landraces were as readily replaced as more common ones. Landrace replacement was unmitigated by increasing rarity yet the most rare landraces have the highest priority for genetic conservation. Some landraces were completely replaced by the farmers in the sample despite a diverse variety portfolio being a risk-reducing strategy in a region where there is a high risk of crop failure. There was little environmental heterogeneity in the marginal, drought-prone areas to slow this decline. The new varieties had an impact on the farming system because sometimes farmers brought additional upland into cultivation. They also introduced these varieties into more favourable, medium land. The strategy of releasing two new upland varieties met with some success in maintaining diversity.     

Characterization of a flint maize (Zea mays L. convar. mays) Italian landrace: I. Morpho-phenological and agronomic traits

Maize (Zea mays L.) landraces have the highest genetic variation and adaptation to the natural and anthropological environment where they have evolved. Surveying both qualitative and quantitative morphological traits of existing landraces may be useful in maintaining their genetic diversity and preserving them from genetic erosion. Our research deals with the morpho-phenological and agronomic characterization of a flint maize landrace, named 'Nostrano di Storo', still grown in an inland hilly environment in the low valley of Chiese River in Trentino, North-Eastern Italy. The majority of plants from twenty field populations proved to belong, with few exceptions (NSt2, NSt9, NSt11), to a single population. It means that the plant material long grown in this area and maintained by local farmers through yearly selection forms a single landrace within which some populations (i.e. NSt1, NSt3, NSt4, NSt7, NSt10, NSt18, NSt19, NSt20) could be considered as most representative and taken as 'core'. This is supported by the fact that the genetic variability was much higher within than between field populations: half of the plant and ear traits investigated did not show any significant difference between populations whereas all traits but two showed highly significant differences within populations. Selection carried out over the years by each farmer according to his own criteria produced little genetic differentiation within the original population. Gene flow among farmer populations, most likely occurred through both pollen dispersion to neighboring cultivated fields and seed exchange among farmers, may help to explain the low genetic differentiation. This information is useful for both planning conservation and recognizing the landrace as a unique germplasm source of specific geographic origin.     

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.     

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.     

Maize diversity in southern Brazil: indication of a microcenter of <Emphasis Type="Italic">Zea mays</Emphasis> L.

‘Microcenters of diversity’ are restricted geographical areas within which a significant diversity of genetic resources is accumulated. Maize genetic variability, one of the largest among cultivated species, particularly in far western Santa Catarina, southern Brazil, has shown a rich store of landraces, conserved on farm by small-scale farmers. Thus, this study aimed to characterize the diversity of Zea mays L. landraces in two municipalities of this micro-region in Santa Catarina, as well as its geographic distribution, developing the census of diversity as a methodological proposal. Diagnosis was made according to the farmers’ knowledge. The field survey was conducted in 70 rural communities involving 2049 farms. The methodology allowed identifying 136 populations of wild relatives, of which some belong to the species Zea luxurians (Durieu and Ascherson) Bird, and 1513 populations of maize landraces, comprising 1078 of popcorn, 337 of common maize, 61 of sweet maize and 37 of flour maize. The identification of 59 morphological groups, the high use, adaptive and agronomic values, and the Shannon index (H′), estimated according to the grain shape (0.79), endosperm type (0.73), size (0.87), color (1.40), and morphological group (3.16), showed at set a considerable diversity distribution conserved on farm in this micro-region. Landrace richness and the presence of wild relative species, associated with the local human activity and sociocultural aspects, allowed to characterize the far western Santa Catarina as a ‘microcenter of diversity’ of Zea mays L.     

Water yam (Dioscorea alata L.) diversity pattern in Brazil: an analysis with SSR and morphological markers

Substantial progress was made in the last decade in understanding the diversity in Dioscorea species. However, most of the studies so far concentrated in the ‘yam belt in Africa’. We present a genetic diversity and structure analysis among commercial and local varieties of water yam (Dioscorea alata L.) in Brazil using microsatellite and morphological markers. Twelve microsatellite primers were used to generate DNA profiles of 72 local varieties and 17 commercial accessions of water yam collected in four different regions in Brazil. Also, four morphological traits were evaluated on individual plants under field conditions. The morphological characterization showed considerable diversity. High polymorphism was found with 100 % polymorphism observed for 11 primers and a discriminating power value of 0.92, on average. We did not observe a strong population structure among sampling regions, while most of the genetic diversity was concentrated within regions (95.9 %). Analysis of the relationship between accessions did not clearly separate the local and commercial genotypes. However, the molecular analyses of D. alata showed high intraspecific diversity in local accessions from different regions in Brazil, with the highest Shannon index value (H′ = 0.41) for the Southeast region. These results confirmed an admixture of accessions in all sampling regions, consistent with the lack of a significant correlation between geographic and genetic distances, suggesting that farmers exchanged water yam materials extensively. The genetic diversity can be explained by the result of a continuous exchange of accessions by farmers throughout Brazil.     

Development of Core Collection in Pigeonpea [<Emphasis Type="Italic">Cajanus cajan</Emphasis> (L.) Millspaugh] using Geographic and Qualitative Morphological Descriptors

Pigeonpea is an important pulse crop grown by smallholder farmers in the semi-arid tropics. Most of the pigeonpea cultivars grown to date are selections from the landraces, with a narrow genetic base. With the expansion of the crop to newer areas, problems of local importance are to be addressed. Hence, an economically feasible and faster germplasm evaluation mechanism, such as a core collection, is required. This article describes the development of core collection from 12,153 pigeonpea accessions collected from 56 countries and maintained at ICRISAT, Patancheru, India. The germplasm accessions from 56 countries were placed under 14 clusters based primarily on geographic origin. Data on 14 qualitative morphological traits were used for cluster formation by Ward’s method. From each cluster ≈10% accessions were randomly selected to constitute a core collection comprising 1290 accessions. Mean comparisons using Newman–Keuls test, variances’ comparisons by Levene’s test, and comparison of frequency distribution by χ²-test indicated that the core collection was similar to that of the entire collection for various traits and the genetic variability available in the entire collection is preserved in the core collection. The Shannon–Weaver diversity index for different traits was also similar for both entire and core collection. All the important phenotypic associations between different traits available in the entire collection were preserved in the core collection. The core collection constituted in the present study facilitates identification of useful traits economically and expeditiously for use in pigeonpea improvement.     

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.     

Analysis of korarima (<Emphasis Type="Italic">Aframomum corrorima</Emphasis> (Braun) P.C.M. Jansen) indigenous production practices and farm based biodiversity in southern Ethiopia

Korarima (Aframomum corrorima (Braun) P.C.M. Jansen) production is declining mainly due to destruction of the plant’s natural habitat. A survey was conducted in the three major korarima growing administrative zones, Gamo Gofa, Debub Omo and Kaffa in southern Ethiopia to assess indigenous production practices, wealth status, farm based biodiversity and household characteristics using participatory rural appraisal (PRA) and semi-structured questionnaires. The wealth is unevenly distributed among households and not significantly different for korarima growers and non-korarima growers. Farmers acknowledged that shortage of shade trees; low yield and lack of improved varieties had contributed to decrease in production area (PA). A total of three distinct named korarima landraces were recorded, with a range from one to three on individual farms implying low farm based biodiversity. More households grew enset (Ensete ventricosum (Welw.) Cheesman) in Gamo Gofa and Kaffa while maize (Zea mays L.) was grown by nearly all households in Debub Omo. Only a few households grew korarima. Most of the household characteristics significantly affected the PA of korarima. The correlation coefficients indicated that the relationship of household characteristics were significant. Findings of this study suggest that the maintenance of shade trees on the main farm field is the main requirement for korarima production.     

Analysis of indigenous production methods and farm-based biodiversity of amochi (<Emphasis Type="Italic">Arisaema schimperianum</Emphasis> Schott) in two sub-zones of Southern Ethiopia

For the first time we report that diverse types of Arisaema schimperianum Schott locally called amochi, are grown and managed as an off-season food crop in Southern Ethiopia. Participatory Rural Appraisal (PRA) and formal survey studies on 204 households were conducted over two consecutive years (2003–2004) in Chencha and Dita sub zones of Southern Ethiopia, to identify indigenous production methods and farm based biodiversity of amochi. Amochi is propagated from seed tubers and tuber parts left in the soil from the preceding harvest and grow during the dry season, February to June. Average share of proportion in the annual household consumption from amochi tubers was 9% and 4% for Chencha and Dita respectively. Uncooked amochi is irritating in contact to skin and mouth. Fifteen amochi types were identified in Dita and 12 in Chencha. They differ in the level of irritation, maturity and yield. Rich farmers with large family size as a working force, large farm size to support larger number of livestock that is source of farmyard manure, have farms with larger diversity of amochi than their poor counterparts, suggesting that its diversity is influenced by house hold characteristics and favoured under relatively fertile soil conditions. In both sub zones women had better experience in identifying amochi types than men. Further study is needed to identify chemical contents; and genetic variation using morphologic and molecular traits, in order to develop a strategy to assess and utilise the existing genetic diversity.     

Molecular diversity of Omani wheat revealed by microsatellites: II. Hexaploid landraces

For millennia, wheat (Triticum spp.) has been grown in traditional aflaj-irrigation systems of remote mountain oases in Oman. However, little is known about the diversity of the ancient landraces used. Given recent reports about the occurrence of novel germplasm in such material, the objective of this study was to evaluate the genetic diversity of hexaploid wheat (Triticum aestivum L.) landraces in relation to their geographic origin using microsatellites. The collection covered most of the cultivation areas in northern Oman where wheat landraces are growing. Total genomic DNA was extracted from six pooled plants representing each accession. A total of 161 wheat accessions were assayed using 35 microsatellite loci in which a total of 305 polymorphic bands were recorded for the 35 microsatellites. The polymorphic information content (PIC) across the 35 microsatellite loci ranged from 0.02 to 0.89 with an average of 0.50. A heterozygosity percentage value of 9.09 was determined and the highest level recorded for accessions from the Batinah district. Rare alleles averaged 1.85 with the highest value being from the Dakhilia district. The results indicated a significant correlation between gene diversity and number of alleles across districts. The correlation coefficient between these two variables over the 35 loci was 0.657, whereby correlation coefficients of 0.718, 0.706, 0.657 and 0.651, respectively, were found for the Batinah, Dhahira, Dakhilia and Sharqia materials. Genetic distances indicated that all landraces were closely related. The cluster analysis discriminated most of the landraces accessions. However, it failed to achieve region-specific groupings of landraces. The present study demonstrated the presence of high diversity in Omani landraces and also indicated the effectiveness of microsatellites to describe it.