Genetic diversity associated with conservation of endangered Dongxiang wild rice (<Emphasis Type="Italic">Oryza rufipogon</Emphasis>)

The wild progenitor species (Oryza rufipogon) of Asian cultivated rice (O. sativa L.) is located in Dongxiang county, China which is considered its the northernmost range worldwide. Nine ex situ and three in situ populations of the Dongxiang wild rice (DXWR) and four groups of modern cultivars were genotyped using 21 SSR markers for study of population structure, conservation efficiency and genetic relationship. We demonstrated that the ex situ conservation of the DXWR failed to maintain the genetic identity and reduced genetic diversity. Therefore, in situ conservation is absolutely necessary to maintain the genetic identity, diversity and heterozygosity. Also, in situ conservation is urgently needed because natural populations in DXWR have decreased from nine to three at present due to farming activity and urban expansion. In DXWR, the three surviving in situ populations had greater expected heterozygosity than any cultivated rice, and were genetically closer to japonica than either the male-sterile maintainer or restorer lines, or indica. Japonica has the lowest genetic diversity of cultivated rice. As a result, DXWR is a rich gene pool and is especially valuable for genetic improvement of japonica rice because these O. rufipogon accessions are most closely related to the japonica as compared to O. rufipogon collected anywhere else in the world.     

Population evaluation in crop wild relatives for <Emphasis Type="Italic">in situ</Emphasis> conservation: a case study for raspberry <Emphasis Type="Italic">Rubus idaeus</Emphasis> L. in the Leningrad region,Russia

Many crop wild relatives are usually widely distributed species, and in this relation a question arises about selecting populations of special importance for conservation. Using Rubus idaeus as an example, we propose a compound selection of wild populations for in situ conservation. Twelve raspberry populations in the Leningrad region have been evaluated from the point of view of their significance for in situ conservation. To exclude the run-wild forms from the evaluation process, we tried to identify them applying a mathematical model developed by statusmetry method. The constructed model is based on morphological features of leaves of primocanes and helps to distinguish the wild forms from the cultivated and run-wild ones. The wild raspberry populations were screened for plants with features useful for cultivated raspberry improvement such as waxy cover presence, yellow fruiting plants, spinelessness, fruiting primocanes and others. The diversity of wild raspberry populations was assessed by variation of morphological features, presence of botanical varieties and polymorphism of seed storage proteins. The results of viability status assessment for the chosen populations reflect the perspectives of their development and permit to determine the strategy and measures for optimal conservation.     

Close Genetic Proximity Between Cultivated and Wild Bactris gasipaes Kunth Revealed by Microsatellite Markers in Western Ecuador

Bactris gasipaes Kunth (peach palm or Pejibaye) is the only domesticated palm of the Neotropics. The genetic relationships between the crop and its wild relatives are still unclear. We undertook field and laboratory work in order to describe differentiation and relationships between the wild and cultivated populations of the species in Western Ecuador, and their possible interactions. A volumetric study was undertaken on the fruits of both populations, as well as a population genetic analysis in order to clarify these relationships. Fruits from cultivated plants collected in the region of sympatry of wild and cultivated plants in North-West Ecuador showed intermediate volumes between those of reference samples for the wild and cultivated plants in allopatry. Using 8 microsatellite loci, we assessed 83 wild and cultivated individuals from Western Ecuador and cultivated plants from Amazonia and Central America as a reference for the cultivated form. We detected high polymorphism in the wild and cultivated samples and low, but significant level of genetic differentiation between wild and cultivated populations. The cultivated population in North-Western Ecuador showed close genetic proximity with the sympatric wild population, consistent with the volumetric study. These results have implications for hypotheses on evolution of this crop and for strategies of genetic conservation of the wild forms.     

Observations on the geographic distribution, ecology and conservation status of several Phaseolus bean species in Costa Rica

Interest in bean genetic resources of Central America has resumed because of disease pressures (e.g., web blight, BGMV) and limitations of current bean varieties. As most of the diversity in landraces has been explored, focus is now on the exploration of wild forms of the primary gene pool and wild species of the secondary gene pool. A germplasm collection was carried out in the field and resulted in the collection of 29 wild populations for six Phaseolus species; it complemented field work done in 1987. Nine more populations were found for P. costaricensis, 10 for wild P. lunatus, one for P. oligospermus, one for P. tuerckheimii, four for wild P. vulgaris and four for P. xanthotrichus. Ninety-three herbarium voucher specimens were collected for 19 populations of the six species (deposited at CR). These results confirm the presence of wild P. vulgaris on both slopes of the central valley of Costa Rica, namely in the life zones bh-MB and bmh-P, and of P. costaricensis in the life zone bmh-MB. These life zones of limited range in Costa Rica have been heavily modified, thus fully justifying the germplasm collection for ex situ conservation. For both species the range of distribution in Costa Rica has been almost completely sampled. The life characteristics of each species that are relevant for their conservation in situ are briefly reviewed. Distribution ranges of each wild bean species are compared with the present extension of national parks, protected areas and fauna/flora sanctuaries, and suggestions for expanding such protected areas are made.     

Processes affecting genetic structure and conservation: a case study of wild and cultivated <Emphasis Type="Italic">Brassica rapa</Emphasis>

When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.     

Maintenance of Squash (<Emphasis Type="Italic">Cucurbita</Emphasis> spp.) Landrace Diversity by Farmers' Activities in Mexico

Squash (Cucurbita spp.) is a common component in traditional cropping systems in Mexico, mainly in the agroecosystem known as the “milpa”, in which squash is cultivated in association with maize (Zea mays), the main crop. Using a questionnaire, 80 farmers were interviewed about crop production and selection practices in order to understand how these factors affect genetic diversity of local squash populations. We found that the most of the farmers who cultivate squash were elderly 59.8 ± 14.5 (mean ± SD; n = 78) years old. Squash varieties in the area were exclusively locally adapted landraces, and had not been replaced by modern squash cultivars. Two cultivated squash species, C. argyrosperma ssp. argyrosperma and C. moschata, had been grown intercropped with maize by 97.5% of the interviewed farmers, but only 50.0% were still producing squash at the time of the study. Farmers recognize typical characteristics of particular varieties within each of the local cultivated squash species, and selection is directed to maintain their identity. Nearly two thirds of the farmers (62.0%) had exchanged seeds of squash for planting, a practice that serves to increase genetic variability in the populations. All of the interviewed farmers were conscious of the possible hybridization between the wild gourd (C. argyrosperma ssp. sororia) and their cultivated squash. Despite various natural and human managed factors identified as contributing to enhancement of genetic diversity in these populations, results of the study show that genetic erosion of Cucurbita is likely in the region in the near future.     

Case studies on breeding systems and its consequences for germplasm conservation

Summary This study gives the results of allozyme diversity within and among 20 wild Lima bean populations uniformly distributed throughout the Central Valley of Costa Rica. The electrophoretic analysis of seven enzyme systems show five monomorphic loci and a relatively low level of polymorphism for the other loci. This moderate level of polymorphism is unexpected for a species for which a fair amount of allogamy rates has been reported, at least among the cultivated forms. The genetic parameters (mainly percentage of polymorphic loci, mean genetic diversity, percentage of heterozygotes and fixation index) indicate a tendency for a predominantly selfing breeding system in the wild Lima beans although some values range between selfing and mixed-animal breeding systems. Very low within-population diversity is observed while a good diversity is found among populations. Results also show a departure from Hardy-Weinberg equilibrium on most analyzed populations in the target site This might be due to populations divided into subpopulations among which no natural crosses occur randomly, to weeding practices or to overlap of generations within some populations. All the results obtained in this work are discussed in view of further studies for the planning of in situ conservation in a quickly evolving tropical environment.     

Phenotypic diversity and delimitation between wild and cultivated forms of the genus <Emphasis Type="Italic">Pyrus</Emphasis> in North-eastern Spain based on morphometric analyses

We investigated morphological evidence that might allow wild Pyrus spp. to be distinguished from cultivated material (Pyrus communis L.) in the North-eastern Iberian Peninsula. 134 pear trees were identified in the wild and characterized by 13 quantitative and 13 qualitative leaf–shoot and fruit traits. The trees were visually classified into two preliminary groups of wild and cultivated material and discriminant functions, based on a reference collection for allocating individuals to one of the groups, were constructed. Both classifications were compared with a near-optimal numerical classification (the two-stage Ward-MLM strategy) using two criteria. The visual assignment of trees allocated 60% of trees to the wild group and 40% to the cultivated group. The overall discrepancy rate between the field classification and the discriminant analysis was low (17.4%). In general, wild individuals had smaller leaves, shorter petioles and more rounded and smaller fruits than their cultivated counterparts. They also had small-to-intermediate petiole widths, thorns on their shoots and straight or convex fruit profiles. However, the Ward-MLM strategy always formed better groups, in terms of the two criteria used, in all the continuous and categorical variables, for both leaf–shoot and fruit traits. Likewise, the agreement between classifications (discriminant analysis and Ward-MLM strategy) was only partial, with some Ward-MLM groups composed of both wild and cultivated material in similar proportions. This result suggests a limited success in identifying genuine wild individuals based on morphometric data, which can be ascribed either to poor phenotypic diversity and lack of distinguishing traits among species or to widespread crossability and subsequent development of hybrid/introgressant populations between wild and cultivated specimens.     

Genetic diversity of Curcuma alismatifolia Gagnep.(Zingiberaceae) in Thailand as revealed by allozymepolymorphism

Allozyme polymorphism at seven loci (TPI, G6PD-2,IDH-1, SKD-2, MDH-1, GOT-1, andGOT-2) was employed to detect the level of geneticdiversity in C.alismatifolia populations from both cultivatedand wild habitats in Thailand. High diversity was observed in allpopulations with relatively lower values in cultivated populations.Percentage of polymorphic loci (P)varied from 85.7–100% in cultivated populations comparedwith 100% in all natural populations. Allele number per locus(A _L) was 3.14 in cultivatedpopulations, and from 2.86–4 in natural populations. Allelenumber per polymorphic locus(A _P) of cultivated andnatural populations ranged from 3.14–3.5 and 2.86–4,respectively. Genetic diversity within populations(H _S) varied from0.586–0.611 in cultivated and from 0.621–0.653 in naturalpopulations. The genetic identity(I _SP) for the species was0.833. The cultivated populations yielded higher value of geneticidentity with highland populations(I _{C /H} =0.776) than with the lowland ones(I _{C /L} =0.754). The analysis of genetic similarities with theNeighbor-Joining algorithm results in the separation ofcultivated populations from all wild populations. One highlandpopulation from the tourist spot, H2, was placed in a separatecluster between the cultivated and other wild populations. It isconsidered as the possible origin of the cultivatedpopulations.     

Genetic resources of <Emphasis Type="Italic">Prunus</Emphasis> (Rosaceae) in India

The genetic diversity in genus Prunus is mainly confined to temperate regions of Himalaya and to a lesser extent in the sub-montane and hilly regions of peninsular India. The cultivated and wild species of Prunus have tremendous potential for improvement and utilization. This paper includes the genetic resources of cultivated and wild useful species of Prunus in India with emphasis on their distribution, potential traits/ useful characteristics and utilization. The information on potential genetic resources of Prunus would be helpful in collection, evaluation, conservation and utilization of species.     

The Vigna angularis complex: Genetic variation and relationships revealed by RAPD analysis, and their implications for in situ conservation and domestication

The present study, using RAPD analysis, was undertaken to characterize genetic variation in three forms of V. angularis, cultivated, wild and weedy forms, and their relationships. The materials used consisted of 171 individuals (plants) or cultivars from 23 populations including 5 wild populations, 6 weedy populations, 6 cultivated populations and 6 populations with plants having wild and weedy or intermediate morphology, denoted here as complex populations. The materials used were collected on Honshu Island, Japan and seeds collected directly from the field were germinated for DNA extraction. In addition, 6 landrace accessions of V. angularis from the genebank were also analyzed. Genetic variation was highest in the wild form (H_g= 0.132; GD = 0.388), followed by the weedy form (H_g= 0.124; GD = 0.341) and the least in the cultivated form (H_g= 0.079; GD = 0.274). Intra-population genetic variation was high in the weedy and in the wild populations. However, inter-population was greater than intra-population genetic variation for all groups of populations studied in the V. angularis complex. 93% of the total diversity in the present study was exhibited by plants from complex populations and specific RAPD bands were found in these populations. Our results provide evidence that complex populations would be a logical focus for efforts to conserve the V. angularis complex in situ. Our results suggest that weedy populations are usually an ecotype of the wild form adapted to a different habitat.     

Genetic Diversity within and Between Populations of Lathyrus genus (Fabaceae) Revealed by ISSR Markers

In order to evaluate the genetic diversity in Lathyrus genus, the Inter Simple Sequence Repeats method (ISSR) was exploited in five populations. These consisted of two cultivated species belonging to section Lathyrus (L. sativus L. and L. cicera L.) and a wild one belonging to the section Clymenum (L. ochrus DC.). Two 3′anchored ISSR primers and two unanchored ones, generated a total of 60 useful polymorphic DNA bands. Our data provide evidence of high molecular polymorphism at the intra- and the inter-specific levels showing that both wild and cultivated forms constitute an important pool of diversity. Moreover, among the generated DNA bands, a 500 bp band, totally absent in the banding patterns of the section Clymenum, appears to be a molecular marker of section Lathyrus. Results provided for lineage and suggest recent origin of these species that might have evolved from a common ancestor producing both L. ochrus species and the two other species L. sativus and L. cicera. These relationships support previous studies based on morphological variation and molecular analysis.     

Evaluation of Wild Lens Taxa for Agro-Morphological Traits, Fungal Diseases and Moisture Stress in North Western Indian Hills

Exploitation of wild gene pool for breeding is a common practice in an increasing number of cultivated plants. The cultivated lentil could not attain the substantial improvement in the yield potential due to loss of genes for higher productivity and lack of resistance against biotic and abiotic stresses. The absence of evaluation data of wild lentils for characters of economic importance, besides biotic and abiotic stresses, is one of the constraints in their use in lentil breeding programme. In the present study, 70 wild accessions from four wild Lens subsp./sp. (L. culinaris subsp. orientalis, L. odomensis, L. ervoides and L. nigricans) along with 3 checks (Precoz, PL-406 and PL-639) were evaluated for phenological and agro-morphological characters, for their reaction to three fungal diseases (wilt, powdery mildew and rust) and screened for tolerance to moisture stress. The wild accessions showed higher performance for branches/plant as compared to cultivated genotypes. Similarly, a few accessions of L. culinaris subsp. orientalis were earlier to flower and had higher seeds and seed yield/plant as compared to cultivated lentil. However, some were comparable with cultivated genotypes for flowers/peduncle, peduncle length and plant height. The mean performance for flowers per peduncle, leaflets per leaf, plant height, seeds and seed yield per plant increased, while decreased for days to flowering and maturity, and branches per plant during the evolution of cultivated lentil from the wild Lens taxa. Of Lens taxa, L. nigricans had the maximum resistant accessions for biotic and tolerance to abiotic stresses. The valuable variation existing among wild accessions can be exploited following introgression with cultivated lentils. It will help in the flow of useful genes from wild to cultivated lentil for generating wide spectrum of variability and its subsequent use in genetic restructuring of lentil.     

Vigna vexillata (L.) A. Rich. Cultivated as a Root Crop in Bali and Timor

Vigna vexillata is considered as a pantropical distributed wild species closely related to the cowpea (Vigna uniculata) and adapted to infertile soils. The species is occasionally used for its storage roots as well as forage and erosion control plant. The objective of this study was to pursue personal communications that V. vexillata has be transformed into a cultivar in Indonesia. Seven Indonesian islands were visited (Java, Bali, Sumba, Flores, Timor, Kalimantan and Sulawesi). Wild V. vexillata was found in Java, Bali, Sumba, Flores and Timor, occasionally used as wild ‘forest food’, and cultivated V. vexillata was found in Bali and Timor, Seven cultivars were collected and two of these were made available for the National Botanic Garden of Belgium. The cultivars were primarily cultivated for their storage roots, propagated by seeds, required no scarified seeds for good germination and formed non-dehiscent pods. On-farm root yields of 18–30 t ha⁻¹ and seed yields of 0.7–1.2 t ha⁻¹ were estimated. A brief discussion about the common names of wild V. vexillata is given and it is proposed to use the name ‘tuber cowpea’ for V. vexillata accessions which are cultivated for their storage roots. The material may be of interest for regions, where the growing season is too short or the rainfall too low for sweet potato and cassava as well as to incorporate cultivar characteristics into wild V. vexillata accessions which are used for their storage roots.     

Assessment of genetic diversity in cultivars and wild accessions of Luohanguo (<Emphasis Type="Italic">Siraitia grosvenorii</Emphasis> [Swingle] A. M. Lu et Z. Y. Zhang), a species with edible and medicinal sweet fruits endemic to southern China,using RAPD and AFLP markers

Genetic variation of wild populations and cultivars of Luohanguo (Siraitia grosvenorii), a plant species endemic to southern China, was assessed using random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers. Based on the results for 130 individuals from seven populations, a high level of genetic diversity of Luohanguo was observed at the species level. The percentage of polymorphic loci (P) was 89.4%, Nei’s gene diversity (H _e) was 0.239, and Shannon’s information index (H _o) was 0.373 based on the combined AFLP and RAPD data. There was a high degree of genetic differentiation, with 45.1% of the genetic variation attributed to differences between the populations. The genetic diversity of the Luohanguo cultivars is much lower than that of wild populations (P = 41.8%, H _e = 0.141, H _o = 0.211), and a distinct genetic differentiation is observed between the cultivars and wild accessions. The pool of genetic variation in the wild populations provides an excellent gene resource for Luohanguo breeding.     

Identification of new sources for resistance to powdery mildew in H. spontaneum-derived winter barley lines

Twenty four barley lines derived from the F ₇generation of crosses between two winter barley cultivars and different accessions of Hordeum spontaneum Koch collected in Israel were tested against a set of ten European and five Israeli powdery mildew cultures, possessing virulence genes which completely match the spectrum of known mildew resistance genes. The comparison of reaction patterns justified the conclusion that new genes for resistance have been conferred from H. spontaneum which also differ from genes previously identified in other wild barley accessions from Israel. Participation in the expression of the resistance reaction of one of the two barley cultivars used in the development of the lines is well documented in some cases. The majority of the lines was found to be highly resistant against all or almost all European isolates, while various kinds of reactions were observed against the Israeli cultures. The effective transfer of novel mildew resistance from H. spontaneum into winter barley confirms similar results with spring barley, indicating natural wild barley populations in Israel as a significant gene pool for yet unexploited mildew resistance in barley.     

Genetic structure and differentiation among grapevines (<Emphasis Type="Italic">Vitis vinifera</Emphasis>) accessions from Maghreb region

Three gene pools representative of Vitis vinifera L. subsp. vinifera (=subsp. sativa Beger) growing in the Maghreb regions (North Africa) from Tunisia (44), Algeria (31) and Morocco (18) and 16 wild grape accessions (Vitis vinifera L. subsp. sylvestris (Gmelin) Beger) from Tunisia were analysed for genetic diversity and differentiation at twenty nuclear microsatellites markers distributed throughout the 19 grape chromosomes. 203 alleles with a mean number of 10.15 alleles per locus were observed in a total of 109 accessions. Genetic diversities were high in all populations with values ranging from 0.6775 (Moroccan cultivars) to 0.7254 (Tunisian cultivars). F _st pairwise values between cultivated grapevine populations were low but found to be significantly different from zero. High F _st pairwise values were shown between wild and cultivated compartments. Two parent offspring relationships, two synonyms and two clones of the same cultivar were detected. The rate of gene flow caused by vegetative dissemination of cultivated grapevine plants was not sufficient to genetically homogenise the pools of cultivars grown in different regions. The Neighbour Joining cluster analysis showed a clear separation according to geographical origins for the cultivated grapevines gene pools and revealed a high dissimilarity between cultivated and wild grapevine. However, three cultivars (Plant d’Ouchtata 1, Plant de Tabarka 3 and Plant d’Ouchtata 3) are very close to wild accessions and may result from a hybridisation between cultivated and wild accessions. The high level of differentiation between cultivated and wild accessions indicates that the cultivated accessions do not derive directly from local wild populations but could mostly correspond to imported materials introduced from others regions during historical times or derived from crossing between them.     

Diversity of aroma patterns in wild and cultivated <Emphasis Type="Italic">Fragaria</Emphasis> accessions

Plant breeders are interested in strawberry species as donors of volatile compounds in breeding programmes because of the diversity and intensity of wild strawberry aroma. Therefore, the topic of this paper is the prospective analysis of four accessions of four wild strawberry accessions in comparison to a standard cultivar of Fragaria × ananassa Duch. by using human sensory, gas chromatography mass spectrometry (GCMS) and gas chromatography–olfactometry (GCO). The wild species have higher aroma intensities compared with the cultivated one. The flavour quality differs significantly. Semiquantitative GC analysis revealed that F. × ananassa cv. ‘Elsanta’ has the lowest content of volatile compounds whereas Fragaria moschata L. ‘Cotta’ has the highest. The aroma impressions, measured by GCO, support the findings of GCMS analyses. The nasal impact frequency (NIF)-profiles of the wild types are more manifold and of higher intensities than those of the cultivated F. × ananassa cv. ‘Elsanta’ which corresponds with the overall flavour impression when tasting the fresh fruits.     

Spontaneous gene flow and population structure in wild and cultivated chicory, Cichorium intybus L.

Spontaneous gene flow between wild and cultivated chicory, Cichorium intybus L., may have implications for the genetic structure and evolution of populations and varieties. One aspect of this crop-wild gene flow is the dispersal of transgenes from genetically modified varieties, e.g. gene flow from GM chicory to natural chicory could have unwanted consequences. With the purpose to identify and quantify crop-wild gene flow in chicory, we analysed introgression in 19 wild chicory populations and 16 accessions of chicory varieties and landraces distributed across Northern, Central and Mediterranean Europe. The analysis used 281 AFLP markers and 75 SSAP markers giving a total of 356 polymorphic markers. Results from model based assignments with the program STRUCTURE indicated many incidents of recent gene flow. Gene flow was observed both between cultivars and wild populations, between landraces and wild populations, between different wild populations as well as between cultivars. Population structure visualized by distance-based clustering showed a North–South geographical structuring of the wild populations, and a general grouping of the cultivars corresponding to known origin. The results indicated, however, that the structuring between the two groups of wild and cultivated types was weak. As crop and wild recipients are genetically close and genes are transferred between the two types rather frequently, focus on mitigating crop-wild gene flow should be increased, before transgenic varieties are cultivated openly.     

Genetic Structure of Wild and Domesticated Populations of Capsicum annuum (Solanaceae) from Northwestern Mexico Analyzed by RAPDs

Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in wild populations and 34.7% in domesticated populations. Mean and total genetic diversity were 0.069 and 0.165 for wild populations and 0.081 and 0.131 for domesticated populations. Parameters of genetic diversity estimated from 54 bands with frequencies ≥1 − (3/n) (n = sample size) showed that 56.7% of the total variation was within and 43.3% among wild populations, whereas 67.8% of the variation was within and 32.2% among domesticated populations. AMOVA indicated that total genetic diversity was equally distributed within (48.9 and 50.0%) and among (50.0 and 51.1%) populations in both wild and domesticated samples. Wild and domesticated populations were clearly resolved in a UPGMA dendrogram constructed from Jaccard’s distances (average GD = 0.197), as well as by AMOVA (17.2% of variance among populations types, p = 0.001) and by multidimensional scaling analysis. Such differentiation can be associated with domestication as well as different origin of gene pools of the wild (Northwestern Mexico) and cultivated (more probably Central Mexico) samples analyzed. The considerable genetic distances among cultivars (average GD = 0.254) as well as the high number of diagnostic bands per cultivar (33 out of 126 bands), suggest that genetic changes associated with domestication could have resulted from artificial selection intervening in different directions, but the inclusion of more domesticated samples might clarify the nature of distinctions detected here.