Analysis of genetic diversity in farmers’ rice varieties in Sierra Leone using morphological and AFLP® markers

The objective of the current research was to investigate the status of rice genetic resources in post-war Sierra Leone using both morphological and amplified fragment length polymorphism (AFLP) data. Specifically, we aimed at investigating farmers’ rice genetic resources for homogeneity and differentiation, and at examining the genetic identity of similarly named varieties, including varieties within Sierra Leone, and between Sierra Leone and Guinea. This research was also motivated by the assumption that genetic erosion might have occurred as a result of the civil war. To determine the level of diversity and genetic relationships among farmers’ varieties of rice recently collected in Sierra Leone, two methods were used using subsets of the collected samples: (1) Using morphological data, 74 samples of 29 different varieties were analysed to investigate the relationship between (a) varieties grown in two districts in Sierra Leone, and (b) the two main cultivated species, Oryza sativa and Oryza glaberrima. A dendrogram largely clustered the varieties according to region and to the species to which the varieties belonged. (2) Using AFLP data, three separate investigations were conducted: (a) 33 samples of 10 varieties were investigated to evaluate diversity within and between varieties. The results indicated that the rice varieties possess different levels of intra-variety variation, whereas inter-variety diversity was high enough to distinguish one variety from the other. In particular, an AMOVA analysis revealed that 38 % of the total variation occurred within varieties, and 62 % between varieties. (b) 37 samples of 18 different varieties were investigated to determine the consistency of naming of varieties by farmers. The results showed that there was consistency in the naming by farmers of traditional varieties, but inconsistency in the naming of newly acquired varieties and cultivars. (c) 12 samples were investigated to check the identity of varieties carrying identical names collected in two separate regions, Sierra Leone and the neighbouring country of Guinea. The results indicated no close genetic relationships between the varieties found in Sierra Leone and Guinea despite similarities in the names given to these varieties by farmers, indicating the influence of different cultivation practices in the two countries.     

Microsatellites and RAPD Markers to Study Genetic Relationships Among Cowpea Breeding Lines and Local Varieties in Senegal

Genetic diversity in local cowpea varieties and breeding lines from Senegal were studied using random amplified polymorphic DNA (RAPD) and microsatellite (SSR) techniques. Among the 61 RAPD primers used, twelve show polymorphism. Fifteen of the 30 microsatellite primer pairs were polymorphic, detecting one to nine alleles per locus. The RAPD and SSR data were analyzed both separately and in combination to assess relationships among genetic lines. Although RAPD provided information on levels of genetic diversity, microsatellite markers are most effective in determining the relationship among cowpea accessions and varieties. The SSR results support the genetic diversification of cowpea in Senegal and underscore their potential in elucidating patterns of germplasm diversity of cowpea in Senegal. An erratum to this article is available at .     

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.     

Exploration of intra- and inter-population genetic diversity in <Emphasis Type="Italic">Hedysarum coronarium</Emphasis> L. by AFLP markers

Amplified fragment length polymorphism (AFLP) markers were used to characterize the genetic diversity within and among natural populations and cultivars of Hedysarum coronarium. Twelve populations within Tunisia were evaluated with three AFLP primer combinations. A total of 207 reproducible bands was detected of which 178 (86%) were polymorphic. The great discriminative power of AFLP markers and their ability to represent genetic relationships among Hedysarum plants was demonstrated. Genetic diversity within and among populations was assessed through Principal Component Analysis (PCA) and cluster analysis by using the Neighbor-joining clustering algorithm. AFLP technology has provided evidence of a high degree of intra- and inter-population genetic diversity in H. coronarium. AFLP banding patterns provided molecular markers correlated with the plants’ geotropism. In addition, AFLP markers can differentiate wild accessions from cultivars. Moreover, geographical origins did not correspond to population clustering.     

A glimpse into the past: Strampelli’s bread wheats legacy

More than 100?years ago, before the rediscovery of Mendel’s laws of inheritance, Nazareno Strampelli started a deliberate crossing programme among Italian and foreign bread wheat genotypes that led to the constitution of over 100 varieties and allowed Italy to significantly increase wheat production. Several varieties enjoyed worldwide popularity and were instrumental in the success of many other breeding programmes. To better understand the reasons of these accomplishments, 84 accessions, representing 50 Strampelli varieties, were characterized for glutenin storage proteins and AFLP patterns, in order to confirm their identification and to assess their genetic diversity. The molecular markers analysis confirmed the correct attribution of most accessions and highlighted the broad genetic variation existing among Stampelli’s varieties. Some genotypes, deemed incompatible with the available pedigree data, were removed from the final analysis. A limited within-variety diversity among genotypes was probably due to incomplete homogeneity and stability of Strampelli materials, but also to the use of heterogeneous local populations as parents.     

AFLP Analysis of Genetic Diversity in Indian Soybean [Glycine max (L.) Merr.] Varieties

AFLP technique was used to assess genetic diversity in 72 soybean varieties under cultivation in India. Selected 12 AFLP primer pairs produced 1319 products of which 1257 were polymorphic (95%). Wide variations were observed for the number of amplification products, percent polymorphism and average polymorphism information content (PIC). The Jaccard's similarity indices (J) based on the AFLP profiles of the 72 soybean varieties were subjected to UPGMA cluster analysis. The dendrogram generated revealed four major clusters, which were strongly supported by the high bootstrap values obtained from analyses of 1000 bootstrap samples. In addition, the Mantel's test for cophenetic correlation with r = 0.955 indicated very good fit of the varieties to a group in the cluster analysis. Some correspondence between the clustering pattern and the pedigree, place of release or target area of the variety was observed. Overall moderately high genetic diversity was observed which appears to be due to the higher genetic diversity prevalent in 12 of the varieties included in three diverse clusters and was indicative of the need to include more diverse germplasm in the soybean improvement programs.     

Genetic diversity analysis of hulless barley from Shangri-la region revealed by SSR and AFLP markers

For adding the hulless barley resources of Shangri-la region to the global barley resource library, a basic work was done by us to assess their genetic diversity of this region. The genetic diversity of 60 hulless barley samples collected from three counties in Shangri-la region of Yunnan Province, were studied using SSR (simple sequence repeats) and AFLP (amplified fragment length polymorphism) markers. A total of 70 alleles were detected for 19 pairs of SSR primers, and 525 band containing 464 polymorphic bands were revealed for 5 pairs of AFLP primers. The value of polymorphism information content (PIC) ranged from 0.03 to 0.86 for SSR primers. The total numbers of alleles were 51, 55, 43 in three populations and the polymorphic bands were 188, 205 and 141. The genetic distances and genetic identity among the three populations showed their close relationship. The gene diversity among populations relative to the total population diversity (Gst) was 0.13 for SSR markers and 0.02 for AFLP markers and indicated that just 13 and 2% variations were among populations, respectively. The UPGMA cluster analysis revealed that all of the samples grouped randomly rather than clustered into distinct groups corresponding to their populations, row types and spring/fall types. We concluded that there was high genetic diversity in the population of Shangri-la region and the formation of diversity was related to complex environment and inhabitants’ traditional practices.     

Identification and genetic relationships of kenaf (Hibiscus cannabinus L.) germplasm revealed by AFLP analysis

Kenaf (Hibiscus cannabinus L.) is one of the world's most economically important fiber crops. In order to identify different varieties, and investigate its diversity and genetic relationships, twenty-three kenaf accessions and two accessions of its relative, roselle (H. sabdariffa var. altissima), were analyzed by morphological characterization and AFLP fingerprinting. It is very difficult to identify kenaf accessions based merely on morphological characters, due to their limited variation. For the AFLP study, a total of 505 polymorphic markers (out of 560) were produced by six selected AFLP primer combinations. The AFLP fingerprinting was effective in identifying all kenaf accessions included in the study. Kenaf and roselle are independent species with close relationships, and great genetic diversity was also detected among the kenaf accessions with different origins, based on the analysis of the AFLP markers. The AFLP analysis strongly supports the opinion that kenaf originated in Africa. It also demonstrated that the dissemination of kenaf was from Africa through Asia to Central and North America.     

Analysis of Genetic Diversity and Relationships in Waxy Rice (Oryza sativa L.) using AFLP and ISSR Markers

Opaque endosperm is the main phenotypic indicator for waxy rice, but other phenotypic and genotypic variation among waxy rice accessions has largely been ignored. Previous studies showed that wide diversity in starch physiochemical properties exists in both indica and japonica waxy rices, especially for starch gelatinization temperature (GT) which could be divided into a high- and a low-GT group. In the present study, amplified fragment length polymorphism (AFLP) and inter-simple sequence repeat (ISSR) molecular markers were employed to examine genetic diversity and relationships of 56 waxy rice accessions. A total of 358 AFLP fragments were amplified with five primer combinations, showing a high level of polymorphism (78.3%). A total of 190 ISSR bands were generated with a single primer and a primer pair, showing a very high level of polymorphism (92.2%). The genetic distance matrices obtained from the two sets of markers were significantly correlated (r = 0.731, P = 0.004). The dendrogram generated with combined AFLP and ISSR markers could clearly differentiate the indica and japonica groups. Newly released varieties and breeding lines within each subspecies tended to be clustered together, whereas landraces were more distantly placed in the dendrogram. Only one AFLP band was found specific to the indica type, while no specific bands were found for starch GT. The implications for the conservation and breeding of waxy rice are discussed.     

Analysis of genetic diversity in a sweet potato (Ipomoea batatas L.) germplasm collection from Tanzania as revealed by AFLP

Sweet potato (Ipomoea batatas L.) is the fifth most important crop in the developing countries after rice, wheat, maize and cassava. The amplified fragment length polymorphism (AFLP) method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection of Sokoine University of Agriculture, Morogoro and Sugarcane Research Institute, Kibaha, Tanzania. AFLP analysis of 97 sweet potato accessions using ten primer combinations gave a total of 202 clear polymorphic bands. Each one of the 97 sweet potato accessions could be distinguished based on these primer combinations. Estimates of genetic similarities were obtained by the Dice coefficient, and a final dendrogram was constructed with the un-weight pair-group method using arithmetic average. AFLP-based genetic similarity varied from 0.388 to 0.941, with a mean of 0.709. Cluster analysis using genetic similarity divided the accessions into two main groups suggesting that there are genetic relationships among the accessions. Principal Coordinate analysis confirmed the pattern of the cluster analysis. Analysis of molecular variance revealed greater variation within regions (96.19%) than among regions (3.81%). The results from the AFLP analysis revealed a relatively low genetic diversity among the germplasm accessions and the genetic distances between regions were low. A maximally diverse subset of 13 accessions capturing 97% of the molecular markers diversity was identified. We were able to detect duplicates accessions in the germplasm collection using the highly polymorphic markers obtained by AFLP, which were found to be an efficient tool to characterize the genetic diversity and relationships of sweet potato accessions in the germplasm collection in Tanzania.     

Genetic diversity of cowpea [<Emphasis Type="Italic">Vigna unguiculata</Emphasis> (L.) Walp.] in four West African and USA breeding programs as determined by AFLP analysis

Cowpea is an important grain legume and hay crop of many tropical and subtropical regions, especially in the dry savanna region of West Africa. The cowpea gene pool may be narrow because of a genetic bottleneck during domestication. Genetic variation within specific breeding programs may be further restricted due to breeding methods, ‘founder effects’ and limited exchange of germplasm between breeding programs. Genetic relationships among 60 advanced breeding lines from six breeding programs in West Africa and USA, and 27 landrace accessions from Africa, Asia, and South America were examined using amplified fragment length polymorphism (AFLP) markers with six near infrared fluorescence labeled EcoRI + 3/1bases/MseI + 3/1bases primer sets. A total of 382 bands were scored among the accessions with 207 polymorphic bands (54.2%). Despite a diverse origin, the 87 cowpea accessions shared a minimum 86% genetic similarity. Principal coordinates analysis showed clustering of breeding lines by program origin, indicating lack of genetic diversity compared to potential diversity. Accessions from Asia and the Americas overlapped and were distinct from West African breeding lines, indicating that germplasm from Asia and the Americas have common origins outside West Africa. US and Asian breeding programs could increase genetic variability in their programs substantially by incorporating germplasm from West Africa, while national programs in West Africa should consider introgression of Asian germplasm and germplasm from other parts of Africa into their programs to ensure long-term gains from selection.     

Social and environmental influences on tartary buckwheat (<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis> Gaertn.) varietal diversity in Yunnan,China

Effective conservation strategies aimed to protect crop genetic resources require multiple sources of information. We used a combination of AFLP genotyping and farmer surveys to understand the extent, distribution and management of tartary buckwheat (Fagopyrum tataricum Gaertn.) diversity in its center of origin in Yunnan Province, China. We found genetic evidence of gene flow in tartary buckwheat throughout the study area, with small but statistically significant regional and village-level components. We also found genetic differentiation by seed color. Although most farmers reported exchanging seed in localized kinship networks, our results imply homogenizing gene flow is occurring. Yi ethnic farmers tend to plant more buckwheat than non-Yi farmers, and we found that in some communities, Yi farmers serve as seed sources for farmers of other ethnicities. Different tartary buckwheat varieties did not have different end uses; rather farmers maintained varietal diversity in order to protect crop yield and quality. Individual farmers’ seed exchange practices reflect their ideas about components of seed quality, as well as priorities in protecting buckwheat yield. From the standpoint of genetic resources conservation, the presence of a culturally rich farmer exchange network and hierarchical structuring of tartary buckwheat genetic diversity demonstrates the importance of maintaining an interlinked community of tartary buckwheat farmers in Yunnan.     

Genetic diversity among varieties of Chia (Salvia hispanica L.)

Chia, Salvia hispanica L., was a staple crop in pre-Columbian Mesoamerica. Despite the great potential of the species as an oilseed crop, little research related to domesticated and wild varieties exists. A study was undertaken to assess genetic diversity among 38 wild and domesticated accessions of S. hispanica collected throughout Mesoamerica by using RAPD markers. Genetic diversity was higher among wild varieties (H _G= 0.15) than all domesticated varieties (H _G= 0.10) and modern commercial domesticated varieties (H _G= 0.02), suggesting a slight loss of diversity accompanying domestication and a near lack of diversity in modern commercial varieties. In addition, the preliminary results indicate that the center of genetic diversity is in the highlands of western Mexico.     

Classification of elite cassava varieties (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) cultivated in Benin Republic using farmers’ knowledge,morphological traits and simple sequence repeat (SSR) markers

Cassava (Manihot esculenta Crantz) is an important food security crop or resource for poor rural communities particularly in Africa. The crop’s ability to produce high yields even under poor conditions and storability of its roots underground for longer periods or until needed makes it a model ‘food security crop’. In Benin Republic, cassava has been recognized as one of the major crop contributing towards dynamic value chains generating incomes for small-holder farmers. The crop is grown all over the country, however, the increased production are mainly recorded from far south and central parts of the country. Genetic improvement of cassava in Benin Republic is limited because of poor knowledge of genetic diversity present within the country. The main objective of this study was to assess the genetic diversity and relationships among elite cassava varieties collected from different regions of Benin using fluorescently labelled simple sequence repeat (SSR) markers and to compare the results with farmer’s knowledge and morphological traits. A total of 96 cultivars collected from major cassava growing areas such as Southern and Central Benin were classified into 24 different groups using farmers’ knowledge, while classification based on 18 morphological traits resulted in five groups. In total, sixteen SSR markers were tested for molecular analysis of the ninety-six cassava varieties. Among the sixteen, twelve SSR markers gave good banding pattern and were used to genotype the varieties. An average of 3.58 and 0.47 for number of alleles and polymorphism information content respectively was observed. The observed heterozygosity (H_o) ranged from 0.23 to 1.0 with an average of 0.66 indicating moderate level of diversity among the cultivars. Based on the proportion of shared alleles and hierarchical clustering, the 96 elite cassava varieties were classified as 74 unique varieties. Principal component analysis and analysis of molecular variance revealed no significant variation between the regions thus, explaining regular exchange of planting materials among cassava farmers across various regions. The moderate level of genetic diversity in famer’s field, revealed in the present study, is a good indication of the need for broadening the genetic base of cassava in Benin Republic and establishing a formal breeding program in the country.     

Genetic diversity of Syrian pistachio (<Emphasis Type="Italic">Pistacia vera</Emphasis> L.) varieties evaluated by AFLP markers

Pistachio (Pistacia vera L.) is a strategic nut tree species in the Middle East which holds comparative advantage over other fruit trees in view of its hardiness, income generation opportunities and benefits for the ecosystem. Yet pistachio cultivation depends on a very narrow genetic base, in spite of the existence of many varieties still marginally exploited. Syria is an important center of diversity for pistachio. A country wide ecogeographic survey in this country was carried out to determine the extent of pistachio genetic diversity and its use. As a whole, 114 accessions were collected from 37 farms to assess diversity at morphological and molecular level. Molecular evaluation was carried out using Amplified Fragment Length Polymorphism (AFLP) technique and performed using seven primer pair combinations. Results from the studies allowed the identification of 25 pistachio female varieties in Syria, some of which unique and described for the first time. Three groups of pistachio diversity were identified by cluster analysis which provides useful information about the distribution of genetic diversity in Syria for enhanced use and sustainable conservation.     

Identification of AFLP Markers that Discriminate Between Cultivated Cotton and the Hawaiian Island Endemic, <Emphasis Type="Italic">Gossypium tomentosum</Emphasis>Nuttall ex Seeman

Interspecific gene flow from crop species into wild relatives may compromise the genetic integrity of native species and in the case of transgenic crops lead to the escape of transgenes into natural populations. Approximately 72% of the upland cotton (Gossypium hirsutum L.) acreage grown in the United States in 2000 utilized transgenic cultivars. The closest relative of G. hirsutum is G. tomentosum Nuttall ex Seeman, endemic to the Hawaiian archipelago. Because these two species are fully interfertile, cultivation of transgenic G. hirsutum in the Hawaiian Islands is restricted. We investigated the possibility of identifying AFLP genetic markers that are diagnostic for each species and thus could be used in future studies to detect introgression between them. In addition, we were interested in comparing levels and geographic patterns of AFLP diversity in G. tomentosum to previous estimates using allozyme data. AFLP analysis led to the detection of 11 and 16 species-specific markers for G. tomentosum and G. hirsutum, respectively. These species-specific AFLP markers will be useful for detecting gene flow between G. hirsutum and G. tomentosum that has occurred in the past and thus might occur in the future if the restrictions on cultivation of transgenic G. hirsutum are relaxed in the Hawaiian Islands. Little genetic diversity and limited geographic patterning were discovered using AFLP markers, consistent with data from previous allozyme studies.     

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.     

Intra-specific DNA polymorphism in pineapple (<Emphasis Type="Italic">Ananas comosus</Emphasis> (L.) Merr.) assessed by AFLP markers

Pineapple (Ananas comosus (L.) Merr.) cultivars, often derived from somatic mutations, are propagated vegetatively. It has been suggested by isozyme data that there is little genetic variation among Smooth Cayenne cultivars. A thorough investigation of the genetic variation within the cultivated speciesAnanas comosus, particularly among commercial cultivars, will provide critical information needed for crop improvement and cultivar protection. One-hundred and forty-eight accessions ofA. comosus and 14 accessions of related species were evaluated with AFLP markers. The average genetic similarity ofA. comosus was 0.735 ranging from 0.549 to 0.972, suggesting a high degree of genetic variation within this species. With AFLP markers, discrete DNA fingerprints were detected for each commercial cultivar, breeding line, and intra-specific hybrid. Self-incompatibility, high levels of somatic mutation, and intraspecific hybridization may account for this high degree of variation. However, major cultivar groups of pineapple, such as Cayenne, Spanish, and Queen, could not be distinctively separated. These cultivar groups are based on morphological similarity, and the similar appearance can be caused by a few mutations that occurred on different genetic background. Our results suggest that there is abundant genetic variation within existing pineapple germplasm for selection, and discrete DNA fingerprinting patterns for commercial cultivars can be detected for cultivar protection. The genetic diversity and relationships of fourAnanas species are also discussed.     

Highly polymorphic AFLP markers as a complementary tool to ITS sequences in assessing genetic diversity and phylogenetic relationships of sweetpotato (Ipomoea batatas (L.) Lam.) and its wild relatives

Comparative analyses of genetic diversity and phylogenetic relationshipsof sweetpotato (Ipomoea batatas (L.) Lam.) and its wildrelatives in Ipomoea series Batataswere conducted using amplified fragment length polymorphism (AFLP) and sequencedata from the internal transcribed spacer (ITS) region of the ribosomal DNA. LowITS divergence among thirteen species of ser. Batatasresulted in poorly resolved relationships. More variable AFLP characters werefound to be more efficient in characterizing genetic diversity and phylogeneticrelationships at both intra- and interspecific levels within ser.Batatas. Highly informative AFLP fingerprints of 36accessions representing 10 species of ser. Batatas weregenerated using only six primer combinations. Of the species examined,I. trifida was found to be the mostclosely related to I. batatas, whileI. ramosissima andI. umbraticola were the most distantlyrelated to I. batatas. The highlypolymorphic AFLP markers are a valuable tool in assessing genetic diversity andphylogenetic relationships of sweetpotato and its wild relatives.     

Analysis of genetic diversity in Indian robusta coffee genepool (<Emphasis Type="Italic">Coffea canephora</Emphasis>) in comparison with a representative core collection using SSRs and AFLPs

Genetic diversity among 40 accessions (Coffea canephora) of robusta coffee genepool available in India was determined in comparison with 14 representative samples from a C. canephora core collection and three accessions of C. congensis, using amplified fragment length polymorphism (AFLP) and simple sequence repeats (SSR) markers. Both these molecular approaches were able to generate unique fingerprints for each of the accessions analysed. All the 12 SSR primers used in the present study were found polymorphic, with an average of six alleles per primer pair. Comparative analysis revealed the higher amount of diversity in representatives from a core collection than in the Indian genepool. Moreover, a total of 205 polymorphic AFLP bands were scored in all the 57 accessions analysed. The genetic relationship among 57 accessions was compared on the basis of SSR and AFLP polymorphisms. Genetic similarity dendrograms showed high correlation between the two marker systems. This study clearly established the high amount of diversity present in core samples, which is not represented in Indian genepool. Furthermore, the three accessions of C. congensis did not exhibit any significant diversity from other robusta accessions supporting the school of thought that C. congensis forms a biotype of C. canephora. The potential use of SSRs and AFLP markers in genetic diversity analysis for better ex situ management and also for exploitation of diversity in breeding programmes is discussed.