Comparative genomics of Eucalyptus and Corymbia reveals low rates of genome structural rearrangement.

BACKGROUND: Previous studies suggest genome structure is largely conserved between Eucalyptus species. However, it is unknown if this conservation extends to more divergent eucalypt taxa. We performed comparative genomics between the eucalypt genera Eucalyptus and Corymbia. Our results will facilitate transfer of genomic information between these important taxa and provide further insights into the rate of structural change in tree genomes. RESULTS: We constructed three high density linkage maps for two Corymbia species (Corymbia citriodora subsp. variegata and Corymbia torelliana) which were used to compare genome structure between both species and Eucalyptus grandis. Genome structure was highly conserved between the Corymbia species. However, the comparison of Corymbia and E. grandis suggests large (from 1-13 MB) intra-chromosomal rearrangements have occurred on seven of the 11 chromosomes. Most rearrangements were supported through comparisons of the three independent Corymbia maps to the E. grandis genome sequence, and to other independently constructed Eucalyptus linkage maps. CONCLUSIONS: These are the first large scale chromosomal rearrangements discovered between eucalypts. Nonetheless, in the general context of plants, the genomic structure of the two genera was remarkably conserved; adding to a growing body of evidence that conservation of genome structure is common amongst woody angiosperms.

Identification of environmentally stable QTL for resistance against Leptosphaeria maculans in oilseed rape (Brassica napus).

KEY MESSAGE: Six stable QTL for resistance against L. maculans (phoma stem canker) have been identified by QTL × environment interaction analysis using data from five winter oilseed rape field experiments. Phoma stem canker, caused by Leptosphaeria maculans, is a disease of worldwide importance on oilseed rape (Brassica napus). Quantitative trait loci (QTL)-mediated resistance against L. maculans in B. napus is considered to be race non-specific and potentially durable. Identification and evaluation of QTL for resistance to L. maculans is important for breeding oilseed rape cultivars with durable resistance. An oilseed rape mapping population was used to detect QTL for resistance against L. maculans in five winter oilseed rape field experiments under different environments. A total of 17 QTL involved in 'field' quantitative resistance against L. maculans were detected and collectively explained 51% of the phenotypic variation. The number of QTL detected in each experiment ranged from two to nine and individual QTL explained 2-25% of the phenotypic variation. QTL × environment interaction analysis suggested that six of these QTL were less sensitive to environmental factors, so they were considered to be stable QTL. Markers linked to these stable QTL will be valuable for selection to breed for effective resistance against L. maculans in different environments, which will contribute to sustainable management of the disease.

Radial head implant diameter: A biomechanical assessment of the forgotten dimension.

BACKGROUND: The effect of radial head implant length has been a subject of controversy, with the impact on clinical outcomes and forearm biomechanics being extensively studied. However, the impact of radial head diameter on forearm load transfer has not been examined. This study examined the influence of radial head implant diameter on forearm load transfer as measured by interosseous membrane tension and radiocapitellar joint contact characteristics. METHODS: An upper extremity simulator was utilized to study five cadaveric specimens with three different radial head implant diameters (-2mm, anatomically sized, +2mm). A load sensing device was woven into the fibers of the central band of the interosseous membrane to quantify its tension. An inter-positional pressure measurement sensor was used to quantify radiocapitellar joint contact force and area. Axial loads of 160N were applied to the forearm during forearm rotation with the elbow at 90° of flexion. FINDINGS: Changes to the radial head diameter did not change radiocapitellar contact force or area (P=0.4 and P=0.5 respectively). There was a linear relationship between radial head diameter and interosseous membrane tension; increasing radial head diameter increases the interosseous membrane tension (P=0.01). INTERPRETATION: Although radial head diameter was not found to alter radiocapitellar contact area or force, the interosseous membrane tension was impacted. After radial head arthroplasty, an increase in radial head implant diameter increases the interosseous membrane tension, with a potential for increased pain and stiffness. There is also a potential for increased proximal radioulnar joint contact pressures; resulting in stem loosening or radio-ulnar pain.

The effect of excision of the radial head and metallic radial head replacement on the tension in the interosseous membrane.

We measured the tension in the interosseous membrane in six cadaveric forearms using an in vitro forearm testing system with the native radial head, after excision of the radial head and after metallic radial head replacement. The tension almost doubled after excision of the radial head during simulated rotation of the forearm (p = 0.007). There was no significant difference in tension in the interosseous membrane between the native and radial head replacement states (p = 0.09). Maximal tension occurred in neutral rotation with both the native and the replaced radial head, but in pronation if the radial head was excised. Under an increasing axial load and with the forearm in a fixed position, the rate of increase in tension in the interosseous membrane was greater when the radial head was excised than for the native radial head or replacement states (p = 0.02). As there was no difference in tension between the native and radial head replacement states, a radial head replacement should provide a normal healing environment for the interosseous membrane after injury or following its reconstruction. Load sharing between the radius and ulna becomes normal after radial head Replacement. As excision of the radial head significantly increased the tension in the interosseous membrane it may potentially lead to its attritional failure over time.

Utility of an image-based technique to detect changes in joint congruency following simulated joint injury and repair: an in vitro study of the elbow.

BACKGROUND: Investigating joint mechanics is important when determining the etiology of osteoarthritis, as degenerative changes are thought to occur due to altered joint mechanics. The objective of this study was to demonstrate the utility of an x-ray computed tomography-based approach to evaluate joint congruency in the setting of subtle kinematic alterations, employing an in vitro model of collateral ligament repair of the elbow. METHODS: Active and passive elbow flexion was performed in 4 and 5 fresh-frozen cadaveric upper extremities respectively using an elbow motion simulator in the valgus gravity dependent positions. The collateral ligaments were sectioned and repaired. A registration and inter-bone distance algorithm were then used to examine ulnohumeral joint congruency (quantified as surface area) throughout elbow flexion. Valgus angulation was also measured. FINDINGS: Following ligament sectioning and repair, there was a 1.2±1.0° increase in valgus angulation in active flexion and a 21.2±26.2% decrease in surface area. In passive flexion, valgus angulation increased 3.3±2.2° and surface area decreased 57.9±39.9%. INTERPRETATION: The technique described to quantify joint congruency proved to be sensitive enough to detect large changes in joint surface interactions inspite of only small changes in traditionally measured kinematics. These changes in joint congruency may, in part, explain the high incidence of arthritis that has been reported following ligament injuries of the elbow, even in the absence of clinically detectable instability. This technique, when adapted for in vivo use, will be a useful tool to evaluate joint function and the effectiveness of treatments non-invasively.

Three-point appraisal of genetic linkage maps.

This paper develops a simple diagnostic for the investigation of uncertainty within genetic linkage maps using a Bayesian procedure. The method requires only the genotyping data and the proposed genetic map, and calculates the posterior probability for the possible orders of any set of three markers, accounting for the presence of genotyping error (mistyping) and for missing genotype data. The method uses a Bayesian approach to give insight into conflicts between the order in the proposed map and the genotype scores. The method can also be used to assess the accuracy of a genetic map at different genomic scales and to assess alternative potential marker orders. Simulation and two case studies were used to illustrate the method. In the first case study, the diagnostic revealed conflicts in map ordering for short inter-marker distances that were resolved at a distance of 8-12 cM, except for a set of markers at the end of the linkage group. In the second case study, the ordering did not resolve as distances increase, which could be attributed to regions of the map where many individuals were untyped.

Randomized clinical trial of interceptive and comprehensive orthodontics.

Focusing public insurance programs on interceptive orthodontics (IO) may increase access for low-income children. This report presents outcomes from a randomized clinical trial (RCT) comparing IO with comprehensive orthodontics (CO) in Medicaid patients. One hundred seventy pre-adolescents with Medicaid-eligible malocclusions were randomized to IO (n = 86) followed by observation (OBS) or OBS followed by CO (n = 84). One hundred thirty-four completed the trial. Models at pre-treatment (baseline) and following ≤ 2 years of intervention and 2 years of OBS (48 mos) were scored by calibrated examiners using the Peer Assessment Rating (PAR) and Index of Complexity, Outcome and Need (ICON). Overall outcomes and clinically meaningful categorical ICON data on need/acceptability, complexity, and improvement were compared. At baseline, groups were balanced by age, gender, ethnicity, and PAR/ICON scores. Most were minorities. Most (77%) were rated as difficult-to-very difficult. Scores improved significantly for both groups, but CO more than IO (PAR, 18.6 [95%CI 15.1, 22.1] vs.10.1 [95%CI 6.7, 13.4]; ICON, 44.8 [95% CI 39.7, 49.9] vs. 35.2 [95%CI 29.7, 40.6], respectively). On average, IO is effective at reducing malocclusions in Medicaid patients, but less than CO. (ClinicalTrials.gov number CT00067379).

Elbow kinematics after radiocapitellar arthroplasty.

PURPOSE: Radiocapitellar arthroplasty has been proposed as a reconstructive option for combined radial head and capitellar deficiency. The purpose of this study was to assess the impact of radiocapitellar replacement on elbow kinematics. We hypothesized that with the medial collateral ligament (MCL) intact, radiocapitellar arthroplasty would replicate normal kinematics, and that a radiocapitellar arthroplasty would more closely approximate normal kinematics than an elbow with a deficient lateral column or with a deficient MCL. METHODS: We tested 7 cadaveric arms in an upper extremity joint simulator. Each arm underwent computed tomographic scanning to aid implant size selection and computer-assisted implant insertion. We obtained kinematic data using an electromagnetic tracking system during elbow flexion. The capitellar and radial head implants were placed through an extended lateral epicondylar osteotomy. We sectioned the anterior bundle of the MCL, leaving the flexor-pronator mass intact. Outcomes of interest were varus-valgus and rotational kinematics of the ulnohumeral joint. RESULTS: The radiocapitellar arthroplasty showed no difference in kinematics compared with the postosteotomy control. The MCL-deficient elbow showed more valgus angulation and more external ulnar rotation than the control or radiocapitellar arthroplasty in the pronated, valgus loaded position. The deficient lateral column demonstrated increased external ulnar rotation kinematics during active elbow flexion. CONCLUSIONS: Radiocapitellar arthroplasty can restore normal elbow kinematics with the MCL intact. If the MCL is deficient, radiocapitellar arthroplasty does not restore normal kinematics. CLINICAL RELEVANCE: Radiocapitellar arthroplasty should be considered in cases of lateral column deficiency because it maintains normal elbow kinematics during active motion. Whereas radiocapitellar arthroplasty improves the stability of the MCL-deficient elbow with deficiency of the lateral column, reconstruction of the MCL may further improve normal kinematics.

Fragility fractures of the distal humerus: What is the optimal treatment?

In light of the growing number of elderly osteopenic patients with distal humeral fractures, we discuss the history of their management and current trends. Under most circumstances operative fixation and early mobilisation is the treatment of choice, as it gives the best results. The relative indications for and results of total elbow replacement versus internal fixation are discussed.

The effect of an anterior biteplate on dental and skeletal Class II correction using headgears: a cephalometric study.

OBJECTIVE: To test the hypothesis that there are significant differences in skeletal and/or dental changes between Class II subjects treated with headgear (HG) compared with those treated with HG plus maxillary acrylic biteplate (BP) discluding teeth. SETTING AND SAMPLE POPULATION: Secondary analysis performed in Department of Orthodontics at the University of Washington. Fifty pre-adolescent Class II subjects were treated with HG as part of a randomized clinical trial (RCT) at the University of North Carolina/Chapel Hill, and 81 similar subjects were treated with HG plus a flatplane maxillary anterior BP for occlusal separation and anterior labial bow at the University of Florida as part of a separate RCT. MATERIAL AND METHODS: This retrospective cohort study examined anteroposterior (AP) and vertical cephalometric changes in two cohorts of Class II subjects. Pre- and post-treatment cephalometric radiographs for each group were obtained from the two centers and measured for dental and skeletal changes. These data were adjusted for differences in magnification and compared using ancova, controlling for important cohort and protocol differences between the two centers. RESULTS: Overbite and maxillary incisor inclinations were reduced significantly more in the HG/BP group. All other vertical and AP changes were not statistically significantly different between the groups. CONCLUSION: The maxillary anterior BP with labial bow is an effective appliance for reducing overbite and retracting incisors but provides no additional AP dental or skeletal benefit over HG treatment.

The impact of capitellar arthroplasty on elbow contact mechanics: Implications for implant design.

BACKGROUND: Radiocapitellar arthroplasty is indicated for capitellar deficiency. Although current implants employ a spherical capitellar surface, the capitellum is elliptical. This has implications for congruency and wear in capitellar arthroplasty. Our objective was to evaluate the contact mechanics of radiocapitellar arthroplasty. We hypothesized that capitellar replacement would decrease joint contact area relative to the native articulation; and an anatomical implant design would replicate more normal contact morphology than a spherical implant. METHODS: Eight paired humeri and radii were potted in a custom jig. A compressive load of 85N was applied with the articulation flexed at 45° in neutral forearm rotation. Joint casts were made and the articular contact area and shape were quantified. Anatomical and spherical capitellar implants were tested against the native radial head (hemiarthroplasty). FINDINGS: The contact areas for the anatomical and spherical hemiarthroplasties were 59 and 51% of the native articulation (P<0.005), while the unicompartmental arthroplasties' contact areas were 84 and 89% (anatomical, spherical) of the native articulation (P<0.01). No implant was superior in recreating the native contact shape. INTERPRETATION: Placement of any capitellar implant resulted in a large decrease in contact area when articulating with a native radial head. This suggests that the radial head cartilage would see a marked increase in contact pressure relative to the native articulation. The unicompartmental arthroplasties demonstrated an even larger reduction in contact area, raising concern about accelerated surface wear. Further investigation needs to correlate these contact mechanics to cartilage wear and implant longevity.

The first meiosis of resynthesized Brassica napus, a genome blender.

Polyploidy promotes the restructuring of merged genomes within initial generations of resynthesized Brassica napus, possibly caused by homoeologous recombination at meiosis. However, little is known about the impact of the first confrontation of two genomes at the first meiosis which could lead to genome exchanges in progeny. Here, we assessed the role of the first meiosis in the genome instability of synthetic B. napus. We used three different newly resynthesized B. napus plants and established meiotic pairing frequencies for the A and C genomes. We genotyped the three corresponding progenies in a cross to a natural B. napus on the two homoeologous A1 and C1 chromosomes. Pairing at meiosis in a set of progenies with various rearrangements was scored. Here, we confirmed that the very first meiosis of resynthesized plants of B. napus acts as a genome blender, with many of the meiotic-driven genetic changes transmitted to the progenies, in proportions that depend significantly on the cytoplasm background inherited from the progenitors. We conclude that the first meiosis generates rearrangements on both genomes and promotes subsequent restructuring in further generations. Our study advances the knowledge on the timing of genetic changes and the mechanisms that may bias their transmission.

Genetic analysis of potassium use efficiency in Brassica oleracea.

BACKGROUND AND AIMS: Potassium (K) fertilizers are used in intensive and extensive agricultural systems to maximize production. However, there are both financial and environmental costs to K-fertilization. It is therefore important to optimize the efficiency with which K-fertilizers are used. Cultivating crops that acquire and/or utilize K more effectively can reduce the use of K-fertilizers. The aim of the present study was to determine the genetic factors affecting K utilization efficiency (KUtE), defined as the reciprocal of shoot K concentration (1/[K](shoot)), and K acquisition efficiency (KUpE), defined as shoot K content, in Brassica oleracea. METHODS: Genetic variation in [K](shoot) was estimated using a structured diversity foundation set (DFS) of 376 accessions and in 74 commercial genotypes grown in glasshouse and field experiments that included phosphorus (P) supply as a treatment factor. Chromosomal quantitative trait loci (QTL) associated with [K](shoot) and KUpE were identified using a genetic mapping population grown in the glasshouse and field. Putative QTL were tested using recurrent backcross substitution lines in the glasshouse. KEY RESULTS: More than two-fold variation in [K](shoot) was observed among DFS accessions grown in the glasshouse, a significant proportion of which could be attributed to genetic factors. Several QTL associated with [K](shoot) were identified, which, despite a significant correlation in [K](shoot) among genotypes grown in the glasshouse and field, differed between these two environments. A QTL associated with [K](shoot) in glasshouse-grown plants (chromosome C7 at 62.2 cM) was confirmed using substitution lines. This QTL corresponds to a segment of arabidopsis chromosome 4 containing genes encoding the K+ transporters AtKUP9, AtAKT2, AtKAT2 and AtTPK3. CONCLUSIONS: There is sufficient genetic variation in B. oleracea to breed for both KUtE and KUpE. However, as QTL associated with these traits differ between glasshouse and field environments, marker-assisted breeding programmes must consider carefully the conditions under which the crop will be grown.

Osteotomy of the head of the radius for partial articular malunion.

Between 1995 and 2006, five intra-articular osteotomies of the head of the radius were performed in patients with symptomatic healed displaced articular fractures. Pre-operatively, all patients complained of persistent painful clicking on movement. Only patients with mild or no degenerative changes of the radial head and capitellum were considered for osteotomy. The operations were performed at a mean of 8.2 months (4 to 13) after injury and the patients were reviewed at a mean of 5.5 years (15 months to 12 years) after the osteotomy. The average Mayo Elbow Performance Index Score improved significantly from 74 before to 88 after operation, with four patients rated as good or excellent (p < 0.05). The subjective patient satisfaction score was 8.4 on a ten-point scale. All osteotomies healed and there were no complications. In this small series intra-articular osteotomy of the head of the radius was a safe and effective treatment for symptomatic intra-articular malunion without advanced degenerative changes.

Rapeseed cytoplasm gives advantage in wild relatives and complicates genetically modified crop biocontainment.

Biocontainment methods for genetically modified crops closest to commercial reality (chloroplast transformation, male sterility) would be compromised (in absolute terms) by seed-mediated gene flow leading to chloroplast capture. Even in these circumstances, however, it can be argued that biocontainment still represses transgene movement, with the efficacy depending on the relative frequency of seed- and pollen-mediated gene flow. In this study, we screened for crop-specific chloroplast markers from rapeseed (Brassica napus) amongst sympatric and allopatric populations of wild B. oleracea in natural cliff-top populations and B. rapa in riverside and weedy populations. We found only modest crop chloroplast presence in wild B. oleracea and in weedy B. rapa, but a surprisingly high incidence in sympatric (but not in allopatric) riverside B. rapa populations. Chloroplast inheritance models indicate that elevated crop chloroplast acquisition is best explained if crop cytoplasm confers selective advantage in riverside B. rapa populations. Our results therefore imply that chloroplast transformation may slow transgene recruitment in two settings, but actually accelerate transgene spread in a third. This finding suggests that the appropriateness of chloroplast transformation for biocontainment policy depends on both context and geographical location.

The effect of surface area digitizations on the prediction of spherical anatomical geometries for computer-assisted applications.

Intraoperative digitization of osseous structures is an integral component of computer-assisted orthopaedic surgery. This study determined the repeatability and accuracy of predicting known radii and center locations of spherical objects for different proportions of digitized surface areas and various sphere sizes. Also, we investigated these accuracies for some relevant near-spherical osseous structures where results from full area digitizations were considered to be true. Digitizations were performed using an electromagnetic tracker with a stylus on the total and fractional surfaces of 10 hemispheres, ranging from 10 to 28mm in radius. Repeatability was quantified by digitizing five trials of the entire surface and various fractional areas of selected hemisphere sizes. Similar trials were conducted on models of a humeral and femoral head, using the full head area as baseline and digitizing 15 and 30mm diameter areas of the full head. Mean error for the predicted radii and center positions of the hemispheres ranged from 0.39+/-0.29 to 0.14+/-0.07mm and 0.52+/-0.31 to 0.22+/-0.12mm, respectively. Repeatability for the predicted radii and centers produced maximum standard deviations of 0.31 and 0.42mm, respectively. All errors decreased as fractional area (40%, 60%, 80% and 100%) increased (p<0.05). Radius of curvature and center position errors for the humeral head model were 1.51+/-2.11 and 2.28+/-1.51mm, respectively. These errors for the femoral head model were 3.37+/-4.14 and 4.25+/-4.14mm, respectively. Errors resulting from the prediction of radius and center indicate that non-spherical anatomical structures are more sensitive to the digitized area, and hence digitization of the largest surface possible seems warranted.

Alterations in myocardial stiffness in elite athletes assessed by a new Doppler index.

BACKGROUND: In elite athletes left ventricular (LV) morphological changes are predicted to alter passive pressure/volume characteristics by reducing myocardial stiffness and increasing compliance. OBJECTIVE: To investigate the utility of a new Doppler tissue index based on the pressure volume relation ((E/Ea)/LVEDD), which provides a measure of myocardial stiffness, and to assess its usefulness in detecting cardiac adaptation in elite rowers. METHODS: Thirty-six international rowers who had trained intensively and a control group of 30 sedentary subjects, matched for age and sex, were enrolled in the study. LV septal and posterior wall thickness, mass, chamber size, transmitral Doppler peak early (E) and late (A) diastolic filling velocities and isovolumic relaxation times were measured. Early diastolic myocardial velocities (Ea) were averaged from four sites at the mitral annulus; diastolic stiffness was assessed with the use of three indices E, Ea and the LV end-diastolic diameter in diastole (LVEDD). The ratio, (E/Ea)/LVEDD, provides a new index of diastolic stiffness. Rowers were further divided into two groups based on the presence or absence of left ventricular hypertrophy (LVH) 12 mm. RESULTS: No significant difference in Ea was found between the two groups, but there was a difference in the stiffness index, which remained after adjustment for body surface area and heart rate (controls 1.48 (0.3) vs athletes 1.17 (0.34), p = 0.016). No difference in stiffness index was found between the groups with LVH 12 mm (1.11 (0.32) vs 1.17 (0.34), respectively, p = 0.68) CONCLUSIONS: Intense training reduces myocardial stiffness despite the development of LVH.

Mechanisms of tooth eruption and orthodontic tooth movement.

Teeth move through alveolar bone, whether through the normal process of tooth eruption or by strains generated by orthodontic appliances. Both eruption and orthodontics accomplish this feat through similar fundamental biological processes, osteoclastogenesis and osteogenesis, but there are differences that make their mechanisms unique. A better appreciation of the molecular and cellular events that regulate osteoclastogenesis and osteogenesis in eruption and orthodontics is not only central to our understanding of how these processes occur, but also is needed for ultimate development of the means to control them. Possible future studies in these areas are also discussed, with particular emphasis on translation of fundamental knowledge to improve dental treatments.

The effect of medial collateral ligament repair tension on elbow joint kinematics and stability.

PURPOSE: Medial collateral ligament (MCL) repair is commonly performed for the management of acute or subacute instability after elbow dislocations and fracture-dislocations. The effectiveness of transosseous repair of the MCL, as is typically performed clinically, in restoring the normal kinematics and stability of the elbow is of interest as is the effect of MCL tensioning on the initial stability of the elbow. The purpose of this study was to determine whether suture repair of the MCL is able to restore the normal kinematics and stability of the elbow and to determine the optimal initial MCL repair tension. METHODS: Six cadaveric upper extremities were mounted in an upper limb joint simulator. Simulated active and passive elbow flexion was generated while the kinematics were measured with the arm in the dependent and the valgus gravity-loaded orientations. After testing the intact elbow, the MCL was released at its humeral attachment and repaired using a transosseous suture technique at three different repair tensions: 20, 40, and 60 N. RESULTS: Medial collateral ligament repair using a transosseous suture technique restored the kinematics and stability of the MCL-deficient elbow. Motion pathways were affected by the magnitude of initial MCL tension. For all arm orientations and forearm positions, the 20-N and 40-N repairs were not statistically different from each other or from the intact MCL. The 60-N repairs, however, were often statistically different than the other groups, suggesting an overtightening that tended to pull the ulna into a varus position-especially in the midrange of flexion. CONCLUSIONS: These data suggest that MCL repair using transosseous sutures provide adequate joint stability to permit early motion. There is a broad range of acceptable tensions for MCL repair, which is a favorable, clinically relevant finding. Clinical studies are needed to validate these in vitro results.

Simple sequence repeats reveal uneven distribution of genetic diversity in chloroplast genomes of Brassica oleracea L. and (n = 9) wild relatives.

Diversity in the chloroplast genome of 171 accessions representing the Brassica 'C' (n = 9) genome, including domesticated and wild B. oleracea and nine inter-fertile related wild species, was investigated using six chloroplast SSR (microsatellite) markers. The lack of diversity detected among 105 cultivated and wild accessions of B. oleracea contrasted starkly with that found within its wild relatives. The vast majority of B. oleracea accessions shared a single haplotype, whereas as many as six haplotypes were detected in two wild species, B. villosa Biv. and B. cretica Lam.. The SSRs proved to be highly polymorphic across haplotypes, with calculated genetic diversity values (H) of 0.23-0.87. In total, 23 different haplotypes were detected in C genome species, with an additional five haplotypes detected in B. rapa L. (A genome n = 10) and another in B. nigra L. (B genome, n = 8). The low chloroplast diversity of B. oleracea is not suggestive of multiple domestication events. The predominant B. oleracea haplotype was also common in B. incana Ten. and present in low frequencies in B. villosa, B. macrocarpa Guss, B. rupestris Raf. and B. cretica. The chloroplast SSRs reveal a wealth of diversity within wild Brassica species that will facilitate further evolutionary and phylogeographic studies of this important crop genus.