Genetic variability in melon based on microsatellite variation

A set of 18 simple‐sequence repeat (SSR or microsatellite) markers was used to study genetic diversity in a collection of 27 melon (Cucumis melo L.) accessions, representing a broad range of wild and cultivated melons. The materials studied were highly polymorphic for SSRs and a total of 114 alleles were detected (average of 6.3 alleles per locus). Cluster analysis suggests the division of these accessions into two major groups, largely corresponding to the division of C. melo in the two subspecies agrestis and melo. The assignment of the accession to the subspecies was generally in agreement with published reports, except for those corresponding to the ‘dudaim’ and ‘chito’ cultivar groups, which, according to the observed SSR variability, should be included in subspecies agrestis. Based on cluster analysis, five groups of accessions were defined. The two most divergent groups include mainly accessions from the Mediterranean which form one group, and accessions from China, Japan, Korea and India forming the other. Both groups shared a low level of intra‐accession variation compared with the other groups, which suggests an erosion of their genetic variability because of drift and/or inbreeding. The remaining accessions, mainly from Central Africa and India, were more variable and may be an important source of genetic variation for melon breeding.     

Inter and intra-population variability of <Emphasis Type="Italic">Jatropha curcas</Emphasis> (L.) characterized by RAPD and ISSR markers and development of population-specific SCAR markers

Jatropha curcas (Euphorbiaceae) is an oil-bearing species with multiple uses and considerable potential as a bioenergy crop. The present investigation has been undertaken to assess the extent of genetic diversity in a representative set of 42 accessions of J. curcas encompassing different crop growing regions in India along with a non-toxic genotype from Mexico as a prelude for utilization of promising and genetically divergent materials in the breeding programmes. Molecular polymorphism was 42.0% with 400 RAPD primers and 33.5% with 100 ISSR primers between accessions indicating modest levels of genetic variation in the Indian germplasm. The within-population variation based on RAPD polymorphism was 64.0% and was on par with the inter-population variation. Polymorphic ISSR markers have been identified that could differentiate the Indian accessions from the Mexican genotype and two of them were converted to SCAR markers. The SCAR primer pair ISPJ1 amplified a 543 bp fragment in all the Indian populations, while ISPJ2 with a specific amplicon of 1,096 bp was specific to the Mexican genotype. Population-specific bands have been identified for the accession from Kerala (2 RAPD markers), Neemuch-1 from Rajasthan (1 each of RAPD and ISSR markers) and the non-toxic genotype from Mexico (17 RAPD and 4 ISSR markers), which serve as diagnostic markers in genotyping. The study indicates an immediate need for widening the genetic base of J. curcas germplasm through introduction of accessions with broader geographical background.     

Variation in some agronomically important characters in a germplasm collection of beet (Beta vulgaris L.)

Summary A geographically representative selection of germplasm of Beta vulgaris, section Beta has been assessed for characteristics important in sugarbeet breeding, including downy mildew resistance, resistance to aphid colonisation and infection by the beet virus yellow complex. The occurrence of maintainer lines for cytoplasmic male-steriles was also investigated. Desirable qualities were found in some accessions, including nothern European wild vulgaris ssp. maritima and some old multigerm cultivars of fodder beets.     

Molecular diversity and genome-wide linkage disequilibrium patterns in a worldwide collection of <Emphasis Type="Italic">Oryza sativa</Emphasis> and its wild relatives

Genetic diversity analysis within a species is vital for understanding evolutionary processes at the population and genomic levels. We report a detailed study of molecular diversity, polymorphism and linkage disequilibrium in three groups of rice (Oryza) germplasm accessions based on 176 SSR markers. The first group included 65 rice (O. sativa L.) accessions introduced from seven countries, including five regions of China. The second group included 58 US rice varieties released in the past 25 years. The third group consisted of 54 accessions of rice wild relatives represented by ten different species. The number of alleles per SSR marker ranged from 4 to 32 with a mean of 16 alleles and the polymorphism information content values ranged from 0.43 to 0.91 with a mean of 0.70. The variation in SSR alleles was a significant contribution to the genetic discrimination of the 177 accessions within the three Oryza groups. Analysis of molecular variance identified deviation from Hardy–Weinberg equilibrium. Principal coordinates analysis clearly separated the accessions into their respective three groups. Neighbor-joining phylogenetic cluster reflects the ordination of each accession. Linkage disequilibrium (D′) averaged 0.75 in wild Oryza spp., and about 0.5 in both US and international O. sativa accessions. Our results showed that LD among adjacent loci in both O. sativa and Oryza spp. accessions is strong enough to be detecting marker-trait association via genome-wide scans.     

Assessment of genetic variability in grapefruits (Citrus paradisi Macf.) and pummelos (C. maxima (Burm.) Merr.) using RAPD and SSR markers

The genetic variability of 38 grapefruit (Citrus paradisi Macf.) and three pummelos (C. maxima (Burm.) Merr..) accessions was evaluated using RAPD, and single sequence repeat (SSR) analyses. Approximately49% of the 198 RAPD were polymorphic, and 4.6 alleles per SSR loci were identified. PIC values changed from 0.093 to 0.450. A UPGMA phenetic tree was constructed and two main grapefruit groups were identified. The grapefruit accessions `do Cabo' and `Siamesa-Filipinas'clustered very close to the pummelos in Group A. The Group B consisted of three sub-groups, which comprised all of the other grapefruit accessions. The majority of grapefruit accessions showed a narrow genetic base suggesting that the observed morphological polymorphism within the group must be associated with somatic mutations, which were not detected by these molecular markers. This revised version was published online in August 2006 with corrections to the Cover Date.     

Molecular marker diversity and bacterial wilt resistance in wild <Emphasis Type="Italic">Solanum commersonii</Emphasis> accessions from Uruguay

Solanum commersonii is a wild tuber-bearing species native to Uruguay with high potential for use in potato breeding programs. Little is known about the genetic diversity within this wild species and the relationship with the resistance to the bacterial pathogen Ralstonia solanacearum. We studied 30 S. commersonii clonal accessions, 20 of which were collected from geographically different areas across the country, while the other ten were grown from seeds from a single plant. Resistance against R. solanacearum was tested and different levels of resistance were found, ranging from delayed wilting to asymptomatic reactions. The genetic variation and the relationships among individuals in this germplasm collection were studied by different molecular markers: Random Amplified Polymorphic DNA (RAPD), Amplified Fragment Length Polymorphism (AFLP) and Microsatellites or Simple Sequence Repeats (SSR). AFLP markers generated the largest number of total and polymorphic fragments per assay unit while SSR revealed the highest frequency of polymorphic bands (100%), followed by AFLP (96.2%) and RAPD (89.4%). In contrast, when comparing the number of different genetic profiles generated, the SSR markers exhibited the lowest discriminatory power. The clustering pattern obtained with the three marker systems showed a similar distribution of the S. commersonii germplasm revealing a high correlation between the three methods employed. All three dendrograms grouped most of the accessions into two main clusters, containing the same accessions regardless of the marker type. Bacterial wilt resistant accessions were present in both clusters. Accessions originated from different seeds of the same plant were grouped within one of the major clusters, and differed in the response to R. solanacearum revealing segregation of resistance. Furthermore, the distribution in two main clusters showed high correspondence with the geographical origin of the accessions, from the north and south of the country, and with the subspecies malmeanum and commersonii morphologically identified.     

Random amplified polymorphic DNA (RAPD) variation in Fagopyrum tataricum Gaertn. accessions from China and the Himalayan region

The diversity among 52 landraces and cultivars of tartary buckwheat (Fagopyrum tataricum Gaertn.) and one accession of its wild ancestor, F. tataricum ssp. potanini Batalin, from diverse geographic origins was examined using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers. Eighteen primers produced a total of 240 fragments, of which 153 (63.75%) were monomorphic and 87 (36.25%) polymorphic bands. UPGMA-based pairwise Jaccard’s coefficient of similarity was used to deduce the relationships among 53 genetically diverse accessions. The similarity between cultivated tartary buckwheat accessions ranged from 0.61 to 1.00. Four distinct clusters were formed which corresponded well with the geographic distribution of the tartary buckwheat. Nepalese accessions showed maximum diversity followed by Chinese accessions. Tartary buckwheat accessions from the Himalayan region of northwestern India revealed a narrow gene pool. The wild buckwheat accession did not group with any of the three cultivated tartary buckwheat groups, and formed its own single-entry group. Genetic similarity (0.59) of Chinese buckwheat accessions with the wild ancestor reaffirmed that cultivated tartary buckwheat originated in the Yunnan province of northwestern China. Consistent with some earlier reports, our study demonstrated the usefulness of the RAPD technique for the characterization of plant genetic resources and assessment of diversity between species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetic variability measures among Bromus catharticus Vahl. populations and cultivars with RAPD and AFLP markers

The objectives of this study were to optimize RAPD and AFLP techniques in B. catharticus, and to determine the genetic variability of populations and commercial prairie grass cultivars with the aforementioned molecular markers. Two populations with contrasting morphological characteristics were evaluated from individual and bulked DNA samples using RAPD markers. Both analyses showed a similar information about inter population variability. Each accession was sampled by a single leaf bulk of 10 plants. Accession similarities were established with 276 RAPD and 714 AFLP bands using Jaccard similarity coefficient. The dendrogram of the accessions using RAPD markers showed that they shared high similarity values (>94%). A similar result was obtained with AFLP markers (similarity values >98%), revealing a narrow genetic basis in the analyzed accessions. Consequently, molecular characterization of germplasm should be considered in addition to morphological criteria, to choose the parental genotypes for breeding programs of this forage crop. The AFLP technique was more efficient to detect DNA polymorphism in our experiments and unique fingerprints were detected for all the accessions. RAPD is a simple and non expensive technique, suitable to estimate genetic similarity. This revised version was published online in August 2006 with corrections to the Cover Date.     

Assessment of the degree of genetic variation in beet based on RFLP analysis and the taxonomy of Beta

Summary Clones derived from Beta vulgaris and Beta maritima were assayed for their ability to detect restriction fragment length polymorphisms (RFLPs) in different beet accessions. The clones able to detect polymorphism were used as genetic markers to assess the degree of genetic variation existing between and within different species of the genus Beta. The data support the current taxonomy of the Beta vulgaris section, while the great genetic similarity found between Beta webbiana and Beta procumbens indicates that they could belong to the same species.Enough variation was found between Beta vulgaris cultivars, allowing the isolation of a sufficient number of genetic markers for the construction of detailed genetic maps.     

Inter and intra-species Inter Simple Sequence Repeat (ISSR) variations in the genus Cicer

Intra and inter-species ISSR variation and use of ISSR markers in determination of genetic relationship were investigated in an accession collection representing twoperennial and six annual Cicerspecies. Screening of Ciceraccessions with SSR primers revealed highly reproducible amplicon profiles with relatively high multiplex ratios. Many of the primers generated amplicon profiles with which not only the differences among species can readily be identified, but also polymorphisms within species could be detected more efficiently. PCR products at 150 gel positions detected using six SSR primers in Cicer accessions were treated as dominant DNA markers and utilized to compute the distances among accessions and species. Cluster analysis of accessions and species revealed groupings that corroborate our previous studies of relationships based on allozyme and AFLP analysis. Consistent with the AFLP analysis carried out in the same accession collection, ISSR-based groupings indicated that perennial C. incisumis genetically close to the annuals of the second crossability group (C. pinnatifidum,C. bijugum, C. judaicum) while C. reticulatum is the closest wild species to the cultivated chickpea. ISSR-based variation estimates were relatively higher when compared to previous estimates computed from RAPD and AFLP data. Technically, ISSR analysis combines the PCR-based targeting of microsatellite-associated polymorphisms with no prior sequence requirement and stringent PCR conditions. Similarly, when compared to AFLP analysis, it is less technically demanding allowing to survey polymorphic loci in the genome. Thus, ISSR-PCR technology is a reliable, fast, and cost-effective marker system that can be used to study genetic variation and genetic relationships in the genusCicer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Selection of wild Cicer accessions for the generation of mapping populations segregating for resistance to ascochyta blight

In order to determine genetically diverse parents for the generation of mapping populations segregating for resistance to ascochyta blight in wild Cicer species, the genetic diversity between a selection of resistant and susceptible accessions was assessed using molecular markers. Twenty Cicer accessions — comprising eight C. reticulatum accessions, six C. echinospermum accessions, five C. bijugum accessions, and one C. arietinum accession — were compared using a combination of seven RAPD primers and seven ISSR primers. A total of 231 polymorphic bands were scored and used to determine the genetic distances between accessions using Jaccard similarity coefficients. The most genetically diverse parents for the generation of intraspecific and interspecific populations segregating for resistance to ascochyta blight are reported. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sources of resistance to diseases of sugar beet in related Beta germplasm: II. Soil-borne diseases

Between 580 and 700 accessions of related cultivated and wild species of the genus Beta were assessed for resistance to four soil-borne diseases of sugar beet: two seedling damping-off diseases caused by the fungi Aphanomyces cochlioides and Pythium ultimum and two diseases of more mature plants, Rhizoctonia root and crown rot, caused by the fungus R. solani, and Rhizomania, caused by Beet necrotic yellow vein virus (BNYVV), a furovirus transmitted by the plasmodiophorid Polymyxa betae. Analysis of resistance data (assessed on an international standardised 1–9 scale of Resistance Scores) indicated that the highest levels of resistance ({RS} 2) to A. cochlioides and P. ultimum were to be found amongst accessions of the more distantly related sections Corollinae (93% of accessions tested) and Procumbentes (10%), respectively; although useful levels could also be found in the more closely related, and sexually compatible, section Beta (1–6%). Resistance to Rhizoctonia was also found in section Beta (5–7%), depending on whether field or glasshouse tests were used, but there was little evidence of generally high levels of resistance to Rhizomania among accessions of this section. None of the accessions of sections Corollinae and Procumbentes exhibited any notable resistance to Rhizoctonia. However, all sections Procumbentes and some sections Corollinae (4%) accessions were highly resistant to Rhizomania. Individuals with high levels of resistance to Rhizomania were identified from within some section Beta and Corollinae accessions, in which there was evidence of segregation.     

Genetic relationship of Mediterranean mandarins (Citrus deliciosa Tenore) using RAPD markers

Summary Random amplified polymorphic DNA (RAPD) analysis was carried out to evaluate polymorphism and genetic similarity between 39 Mediterranean mandarin genotypes. One hundred eleven amplification products were identified using 21 random primers. An average of 2.2 RAPD markers was obtained for each primer, corresponding to 42% of the amplification products. Genotype-specific RAPD markers were also found, mainly in known hybrids. UPGMA cluster analysis revealed the low level of genetic variation between accessions of Mediterranean mandarins, whereas their hybrids with other Citrus species showed greater genetic dissimilarity. Twenty accessions yielded very similar patterns, suggesting either that they could be a single clone, or that the technique was not able to detect genomic variation. However, for the other specimens genetic polymorphism can easily be detected by RAPD, although the genetic variation between accessions was quite low. The large number of hybrids and the low polymorphism between accessions support the hypothesis that Mediterranean mandarins are all true hybrid of Common mandarins (Citrus reticulata Blanco).     

Estimation of between and within accession variation in selected Spanish melon germplasm using RAPD and SSR markers to assess strategies for large collection evaluation

The population structure of 15 Spanish melon (C. melo L.)accessions, mostly of Group Inodorus, was assessed by the analysis of 16individuals of each accession using 100 random amplified polymorphic DNA (RAPD) bands produced by 36 primers, and allelic variation at 12microsatellite (SSR) loci (23 alleles). A relatively high level of polymorphism (25.6%) was detected using RAPD markers, and eight SSR loci (66.7%) were useful in discriminating accessions. Cluster analysis using RAPD- and SSR-based genetic distance estimates resulted in similar and consistent groupings of most of the accessions studied. The mean genetic distance and standard error among accessions estimated by RAPD variation was 0.421 ± 0.099, and mean SSR-based genetic distance estimate was 0.285 ± 0.141. Albeit many dominant markers examined were fitted to a 3:1 test ratio, deviation from this ratio and from Hardy-Weinberg expectations for many SSR loci suggests that some populations were in genotypic disequilibrium. Moreover, a higher level of genetic variation was observed between Cassaba market classes than within accessions, suggesting that, depending upon the accession, allelic fixation has occurred in these populations. The relatively high level of heterogeneity observed (different band morphotypes and cluster grouping within a particular market class), however, indicates that the Spanish melons examined possess a relatively broad genetic background. An appraisal of accession population structure such as the one reported herein indicates that bulk sampling techniques coupled with molecular analysis techniques that employ a unique array of discriminating markers can provide information leading to effective strategies for diversity analyses of large collections. This revised version was published online in August 2006 with corrections to the Cover Date.     

Comparative analysis of cultivated melon groups (Cucumis melo L.) using random amplified polymorphic DNA and simple sequence repeat markers

Random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers were used to characterize genetic relationships among 46 accessions in two C. melo L. subsp. melo (Cantalupensis, Inodorus) and subsp.agrestis (Conomon, and Flexuosus) groups. Genetic distance (GD) estimates were made among and between accessions in four melon market classes [Galia, Ogen, Charentais, and Shipper (European and U.S. types)] of Cantalupensis, one market class of Inodorus (Cassaba and Honey Dew), one accession of Conomon, and one accession of Flexuosus by employing three GD estimators; simple matching coefficient, Jaccard's coefficient, and Nei's distance-D. Differences detected among 135 RAPD bands and 54 SSR bands (products of 17 SSR primers) were used to calculate GD. Band polymorphisms observed with 21 RAPD primers and 7 SSR primers were important (p =0.01) in the detection of genetic differences. Estimators of GD were highly correlated (p 0.0001; r_s = 0.64 to0.99) when comparisons were made between estimation methods within a particular marker system. Lower correlations (r_s = 0.17 to 0.40) were detected (P > 0.001) between marker systems using any one estimator. The GD of the Conomon and Flexuosus accessions was significantly different (p> 0.001)from the mean GD of all the market classes examined. The mean GD (Jaccard's coefficient) among accessions of Ogen, Galia, Cassaba, Charentais, European shipper, and U.S. shipper groups was 0.11 ± 0.04, 0.33± 0.09, 0.21 ± 0.04, 0.26 ± 0.10, 0.17± 0.05 and 0.22 ± 0.08, respectively. Market classes were distinct (p > 0.001), such that GDs between Galia and other accessions were the largest(mean GD 0.34 to 0.35), and GDs between Ogen and other accessions were the smallest (mean GD 0.29 to 0.30). Contrasts between the U.S. shipper cultivar Top Mark and accessions within any market class was relatively large (mean GD = 0.42 ± 0.06). Empirical estimations of variances associated with each marker type in the accessions examined indicated that, per band, lower coefficients of variation can be attained in the estimation of GD when using RAPDs compared to SSRs. Nevertheless, the genetic relationships identified using these markers were generally similar. The disparity between the analyses of the two markers made may be related to the amount of genome coverage which is characteristic of a particular marker system and/or its efficiency in sampling variation in a population. Results of RAPD marker analysis suggest that 80 marker bands were adequate for assessing the genetic variation present in the accessions examined. This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessment of genetic relatedness of the genera Ananas and Pseudananas confirmed by RAPD markers

Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132 (89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated. The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular and morpho-physiological characterization of sea,ruderal and cultivated beets

Beta vulgaris genetic resources are essential for broadening genetic base of sugar beet and developing cultivars adapted to adverse environmental conditions. Wild beets (sea beets, B. vulgaris spp. maritima and their naturalized introgressions with cultivated beets known as ruderal beets) harbor substantial genetic diversity that could be useful for beet improvement. Here, we compared molecular and morpho-physiological traits of wild beets collected on the Adriatic coast of Italy with sugar beet using eight primer-pairs amplifying 194 polymorphic fragments and four root traits (glucose and fructose content in the root tip, root elongation rate, number of the of root tips, total root length and its distribution among diameters ranges). Genetic diversity was higher in the sea beet accession, which may be due to the highly variable selection pressures that occur in heterogeneous ecological niches, compared with the ruderal and cultivated beets. Sea and sugar beet accessions showed contrasting root patterns in response to sulfate deprivation: sugar beet showed an increase of reducing sugars in the root tips and higher root elongation rate, and the sea beet accession showed an increase in root tip number, total root length and fine root length (average diameter < 0.5 mm). The ruderal beet showed intermediary responses to sea and sugar beet accessions. AFLP and morpho-physiological cluster analyzes showed sea, ruderal and cultivated beets to be genetically distinct groups. The results of this study indicate variability in response to sulfate deprivation is present in undomesticated beets that could be deployed for sugar beet improvement.     

Agro-morphological characterisation of common vetch and its close relatives

The Vicia sativa aggregate, which includes the common vetch, is a complex of six closely related tax a which combines cultivated, weedy and wild forms. In this study 454 accessions with an emphasis on Mediterranean and Central Asian accessions have been compared for 22 key agro-morphological and phonological characters. The agronomic potential of the different members of the aggregate is assessed and useful variation existing in the collection is determined. Geographic patterns of the agronomic variation are studied to determine sources of useful variation. In both sub sp. cordata and sub sp. sativa accessions were found which had higher yields than the checks, consisting of three promising accessions. Sub sp. macrocarpa needs a longer growing season than the other tax a to reach its full potential. The other three tax a in the aggregate all had quite low yields. Important variation in shattering of pod sand in tolerance to moderate frost and resistance to the Sitona weevil was found in most subspecies of the aggregate. Variation in phenological characters appeared to be related to the latitude from which the accession was collected. This revised version was published online in July 2006 with corrections to the Cover Date.     

RAPD analysis of interspecific relationships in presumably apomictic Cotoneaster species

A few of the approximately 300 Cotoneaster species described are diploid but the majority appear to be polyploid. The occurrence of apomixis inpolyploid Cotoneaster species has been reported but never proven with genetic markers. We have used 76 polymorphic RAPD markers to investigate the breeding system and phenetic grouping of some critical taxa, including a total of 19 plant accessions representing 13 mostly European species in the series Cotoneaster. Three to four individual plants, raised from seed from the same original plant, were analyzed for each of three accessions to investigate the possible occurrence of apomictic seed set. Absolutely congruent RAPD profiles were encountered among seedlings from one accession, whereas we found one or two marker differences among seedlings from the other two accessions. Genetic similarities among the different accessions were analyzed with a UPGMA-derived dendrogram. The most deviant taxon was the Chinese C. albokermesinus. A group withC. soczavianus and C. tomentosus was rather isolated from the remainder, as was also C. kullensis. Among the remaining taxa, two well supported clusters were found: (1) C. antoninae and C. uralensis, and (2) C. integerrimus and C. raboutensis, whereas the other five species (C. canescens, C. niger, C. scandinavicus, C. juranus, C. cambricus) formed a poorly supported cluster with no clear substructuring. A principal coordinate analysis yielded results that were in good correspondence with the dendrogram. Again C. albokermesinus appears to be totally isolated from the other species. In addition, two well-defined and rather isolated groups were found: (1) C. tomentosus and C. soczavianus, and (2) C. antoninae and C. uralensis, with the remainder comprising a loosely defined group. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evaluation of genetic variation in Lachenalia bulbifera (Hyacinthaceae) using RAPDs

RAPD (randomly amplified polymorphic DNA) analyses were carried out on 21 accessions of Lachenalia bulbifera (Cyrillo) Engl. Five pre-selected primers produced an average of 88% polymorphisms. Fifteen of the 21 accessions could be identified using the five primers. In a pairwise comparison genetic distance values ranging from 0.11 to 1.08 were obtained. These values reveal a high amount of variation within the species. The genetic distance values within the tetraploid and hexaploid groups on the south coast were low, but values were high between the groups on the south coast and those on the west coast. A dendogram was constructed from the RAPD banding profiles, using UPGM cluster analysis. The dendogram clusters certain accessions together. These clusters are supported by their geographical locality and chromosome data. The hexaploid group, tetraploid group and octoploid group on the south coast are respectively clustered together. It is concluded that RAPDs can be used to assess the genetic variation at an intra-specific level in Lachenalia. This revised version was published online in July 2006 with corrections to the Cover Date.