Genetic diversity in tolerance of wild <Emphasis Type="Italic">Avena</Emphasis> species to aluminium (Al)

An evaluation of diversity of aluminium (Al) tolerance of 180 genebank accessions of diploid, tetraploid and hexaploid of wild Avena species from the world collection of the N.I. Vavilov Institute of Plant Genetic Resources (VIR) showed that the accessions with a high degree of aluminium tolerance belonged to the diploids A. canariensis, A. longiglumis and A. wiestii, the tetraploids A. barbata, A. vaviloviana, and hexaploids A. ludoviciana and A. sterilis. A comparison of the data on Al tolerance with the soil conditions demonstrated that most highly tolerance accessions tend to be collected on different type of soils. According to the results of the principal component analysis, preliminary screening for Al tolerance can be carried out among hexaploid species with higher degree of plant resistance to pathogens.     

Characterization of a world collection of <Emphasis Type="Italic">Agropyron cristatum</Emphasis> accessions

The genetic diversity was studied of 115 Agropyron cristatum accessions from 17 countries. Tetraploids were the most common (74.8%), followed by diploid (16.3%) and hexaploid (6.9%). We observed a relation between geographic distribution and ploidy level. The tetraploids, the most widespread, were found from Europe through Russia to East Asia. The diploids appeared over the same general range, except in Turkey, Iran and Georgia where no diploid accessions were found. Hexaploid accessions mainly came from a region comprising the east of Turkey, the north of Iran and Georgia. A selection of 71 accessions, including all three ploidy levels, were analyzed by capillary electrophoresis using six wheat simple sequence repeat (SSR) markers. All markers presented high levels of polymorphism, generating 166 different alleles ranging in size between 84 and 256 bp. Based on polymorphic information content values obtained (0.579–0.968), all the SSRs were classified as informative markers (values?>?0.5). According to the dendrogram generated, all the A. cristatum accessions were distinctly classified. Diploid, tetraploid and hexaploid accessions are not clearly differentiated from each other on the basis of SSR markers. A field experiment was conducted to morphologically characterize 18 accessions including the three ploidy levels. Significant differences were found between the accessions in spike length, spike width and number of spikelets per spike. All the cytological, molecular, and morphological data demonstrate the high genetic diversity present in A. cristatum, making it a valuable resource for future breeding programs.     

Size homoplasy and mutational behavior of chloroplast simple sequence repeats (cpSSRs) inferred from intra- and interspecific variations in four chloroplast regions of diploid and polyploid <Emphasis Type="Italic">Triticum</Emphasis> and <Emphasis Type="Italic">Aegilops</Emphasis> species

Chloroplast simple sequence repeats (cpSSRs) are widely distributed in the chloroplast genomes of all plant species, and are frequently employed for genotypic and phylogenetic analysis. However, information on intra- and interspecies variation in cpSSRs is lacking. In this study, we sequenced four intergenic (non-coding) chloroplast DNA regions in 57 accessions of 12 tetraploid, and 16 accessions of 4 hexaploid species of Triticum and Aegilops. These sequence data added to our previous data for diploid species in the same chloroplast regions. Intra- and interspecific genetic variation was analyzed for a total of 189 accessions of 13 diploid, 12 tetraploid, and 4 hexaploid species of Triticum and Aegilops, such that all species were represented by multiple accessions. The data were used to infer phylogenetic relationships within and among Triticum and Aegilops species. Based on this robust phylogenetic tree, seven of eight cpSSR loci clearly exhibited “size homoplasy,” referring to the fact that cpSSRs of identical size and DNA sequence can arise even if the alleles are not descended from a common ancestor. These data indicate that cpSSRs should be used with caution in phylogenetic analyzes. Interestingly, as observed from several previous studies, our data also suggest that observed mutation rates may increase significantly when mononucleotide (homopolymer) repeat numbers reach or exceed 9 bp. In the present report, using this sequence data set involving cpSSRs, 81 unique haplotypes among 189 accessions were detected, and five tetraploid Triticum and Aegilops species were successfully identified and genotyped. Our results indicate that combinations of nucleotide substitutions, indels and SSRs of chloroplast nucleotide sequences are available for genotyping at the species accession level.     

Cytological characterisation of the underutilized forage crop Onobrychis viciifolia Scop. and other members of the Onobrychis genus

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume that possesses beneficial properties in the context of sustainable agriculture. A germplasm collection of O. viciifolia was assembled from many geographic regions, as well as a collection of Onobrychis species that might be crossed with O. viciifolia to improve its biological and agronomic properties. The objective of the present study was to obtain cytological information for a broad range of O. viciifolia varieties and related species, in order to confirm and extend previous findings. The study set was 143 accessions of O. viciifolia as well as 34 accessions of 17 other species from the Onobrychis genus. Three of the O. viciifolia accessions were diploid (2n = 2x = 14) and the remainder tetraploid (2n = 4x = 28). Chromosomes were <5 μm in length. Among the other Onobrychis species, roughly half were found to be diploid and the other half tetraploid, with two species, O. arenaria (Kit.) DC. and O. alba subsp. laconica (Orph. ex Boiss.) Hayek, including a mixture of diploid and tetraploid accessions. The basic number of chromosomes was seven, except for O. aequidentata (Sm.) d’Urv. and O. crista-galli Lam., where it was eight. The 2C value for O. viciifolia was estimated at 2.5 pg. These cytological data will be valuable as part of a pre-breeding programme aimed at the eventual production of improved O. viciifolia varieties for use in sustainable agriculture.     

Investigation of genome polymorphism and seed coat anatomy of species of section Adenolinum from the genus Linum

Twelve species of section Adenolinum from genus Linum have been studied using cytogenetic methods (DAPI/C-banding, Ag-NOR staining, FISH with 5S and 26S rDNA probes), RAPD analysis, and seed surface ultrastructure and seed coat anatomy investigation. Karyotype analysis revealed that these species have a chromosome number of 2n = 18 or 2n = 36. The DAPI/C-banding patterns enabled the identification of all chromosomes and revealed the similarities in chromosome patterns in all of the studied species. It was found that 18-chromosome plants are diploids, whereas 36-chromosome forms are tetraploids. In diploid species, 5S and 26S rRNA genes are located in similar positions on a single pair of chromosomes or on two chromosome pairs in tetraploids. Ag-NOR staining showed NOR activity in both genomes of tetraploids. RAPD analysis and seed coat anatomy investigation revealed some interspecies differences. Species from nearby areas have more similar RAPD characteristics compared with more geographically distant species. The results of this study may serve as an additional argument in favour of a monophyletic origination of the Adenolinum species and its strong isolation from other Linum species.     

Morphological,SSR and ploidy analysis of water yam (<Emphasis Type="Italic">Dioscorea alata</Emphasis> L.) accessions for utilization of aerial tubers as planting materials

The high cost and supply shortage of seed yam propagules for planting are major constraints in yam production. In the water yam (Dioscorea alata L.), aerial tubers have potential as alternative sources of planting material. In this study, we investigated morphological, molecular and ploidy variation across multiple aerial tuber producing accessions of Dioscorea alata. Initial screening of over 800 accessions from the International Institute of Tropical Agriculture germplasm collection for aerial tuber production identified a subset (15 %) of accessions, which produced aerial tubers. The aerial tuber producing accessions (along with 18 non-aerial tuber accessions) were further characterized for phenotypic and ploidy variation. In addition, using SSR markers we characterized the genetic diversity amongst all of the aerial tuber producing accessions, along with six non-aerial tuber producing accessions. Multiple Correspondence Analysis (MCA) using morphological data grouped the accessions according to their aerial tuber production. The aerial tuber production characteristics of accessions were associated with phenotypic variables and ploidy levels. The MCA analysis revealed three main groups consisting of; Group 1) all non aerial tuber producing accessions (n = 15), hastate leaf shape, less or no anthocyanin pigmentation and diploid (2n = 2x = 40), Group 2) group with some aerial tuber producing accessions, different extent of anthocyanin pigmentation, sagittate leaf shape, mainly diploid (n = 44) and three triploid (2n = 3x = 60) and 3) a group where all individuals bear aerial tuber, cordate leaf shape, intermediate anthocyanin pigmentation and majority (n = 74) tetraploid (2n = 4x = 80) and three triploid individuals. Aerial tuber production may be subject to a genome dosage effect as an increase in aerial tuber production was associated with increased ploidy level. For instance, tetraploid plants produce more aerial tubers per sprout than either triploids or diploids. Principal coordinate analysis based on SSR markers using Jaccard’s coefficient also revealed distinct groups associated with the pattern of aerial tuber formation, leaf shape and anthocyanin pigmentation. Overall our study indicates the usefulness of combining SSR markers, ploidy level and phenotypic data for identification and classification of Dioscorea alata accessions according to their extent of aerial tuber production.     

Characterization of the missing diploid progenitors of the common oat

Summary The genomic formula ACD of the hexaploid oat,Avena saliva, AC for the tetraploid speciesA. magna andA. murphyi, and the hypothesis that the A genome was contributed byA. strigosa group and C genome byA. ventricosa—A. eriantha group, have derived from karyotype studies. Cytogenetic evidence, however, does not support any of the known diploid oats as possible progenitors of the hexaploid oats.A. magna, and to a lesser extent,A. murphyi, are closer to the hexaploids than other tetraploids. Morphologically, these tetraploids resemble thesterilis type, which is apparently the genuine form of the hexaploid oats, with a few important differences. Spikelet morphology of these three wild oats indicates some features that must also occur in one or more of their diploid progenitors: 1. Ventricose diaspore containing the entire spikelet, 2. Long and broad callus with blunt tip, 3. Awn insertion at the lower one quarter of the lemma, 4. Close proximity of lemma tips of the two lower florets.A. magna andA. murphyi have narrow ecological ranges and are restricted to heavy alluvial soils which are now mostly under cultivation. It is likely that on similar soil type the diploid progenitors would grow as well and a search for them should be attempted there. Morocco is the most promising area for finding the missing diploids. Not onlyA. magna andA. murphyi grow there, but except one, all other annual oat species as well.     

Identification of genomic constitutions of <Emphasis Type="Italic">Oryza</Emphasis> species with the B and C genomes by the PCR-RFLP method

Oryza officinalis complex is the largest and the most complicated group in the genus Oryza L., consisting of about ten species with the B, C, BC, CD, and E genomes. Taxonomy and identification of the species, particularly those with the B, C and BC genomes, are difficult due to the similar morphology and overlapping distribution of some species. The difference in ploidy levels of some species adds more complexity. In the present study, we surveyed 64 accessions of rice germplasm in the O. officinalis complex using RFLP analysis of PCR-amplified Adh genes in addition to chromosome counting. The results confirmed that all O. rhizomatis accessions are diploids with the C genome, whereas all O. minuta accessions are tetraploids having the BC genome. However, both diploid and tetraploid forms were found for the accessions identified in the genebank as O. officinalis, O. punctata and O. eichingeri. The tetraploid form of O. officinalis with the BC genome is exclusively distributed in India and has been described as O. malampuzhaensis. The tetraploid form of O. punctata which has been called O. schweinfurthiana by some workers was found to be as widely distributed as its diploid form in Africa. It is noteworthy that two accessions that had been determined as tetraploid O. officinalis were actually belonging to a species with the CD genome (O. latifolia). Our results promote a better understanding of the genomic constitutions of many accessions in the O. officinalis complex and correct determination of the genebank material, which serves as an important basis of germplasm cataloguing for further research and utilization.     

Genetic diversity and origin of cultivated potatoes based on plastid microsatellite polymorphism

The origin of cultivated potatoes has remaining questions. In this study, 237 accessions of all cultivated species and 155 accessions of wild species closely related to cultivated potatoes, including their putative ancestors, were analyzed using 15 plastid microsatellites (SSRs) to investigate genetic diversity and their relationships with the wild species. We here used polymorphic plastid SSRs we developed from potato plastid genome sequences as well as already known plastid SSR markers. All 15 loci were polymorphic and identified a total of 127 haplotypes. Dramatic decreases in levels of genetic diversity were revealed in landraces in comparison with wild ancestor species. The plastid SSR results showed a decrease in haplotype number and diversity from Peru to both north and south. Phylogenetic analysis revealed two distinct groups. One of them, group A, contained the majority of accessions of cultivated species of the Solanum tuberosum Andigenum group including all accessions of cultivated diploid and triploid cytotypes of this group (S. chaucha, S. phureja, and S. stenotomum by a former taxonomic system) and most of tetraploid accessions of the S. tuberosum Andigenum group (S. tuberosum subsp. andigenum), and the majority of accessions of wild ancestors from the northern members of the S. brevicaule complex. Another group B comprised most of the wild species accessions and almost exclusively hybrid cultivated species which have introgressed plastid genomes from the other wild gene pools. Lack of clustering of traditional cultivated species (as used above) support a revised group classification of S. tuberosum.     

Copper Uptake, Physiology and Cytogenetic Characteristics in Three Matricaria chamomilla Cultivars

Selected physiological parameters and copper uptake by three chamomile (Matricaria chamomilla) cultivars (two tetraploid????Lutea?? and ??Unknown?? and one diploid????Novbona??) exposed to 60 ??M Cu over 7 days were studied. Genome size was 10.6 and 5.5 pg DNA/2C and chromosome number 2n?=?36 and 2n?=?18 in tetraploids and diploid, respectively. Root tissue water content and dry biomass were more reduced in diploid cultivar. Soluble proteins were depressed by Cu excess in all cultivars without respect to ploidy. Lignin accumulation and cinnamylalcohol dehydrogenase activity was the highest in Novbona. Phenylalanine ammonia-lyase activity was stimulated in tetraploid but reduced in diploid roots. Diploid contained higher amount of Cu and soluble phenols in both shoots and roots. Sulphur-containing amino acids were stimulated in Cu-exposed shoots independently on ploidy level. Potassium content was more reduced in the diploid cultivar. Our data indicate that induction of phenolic metabolism is faster in diploid cultivar which also contained higher amount of Cu. In this view, polyploidisation is a good tool for the reduction of shoot metal accumulation and growth tolerance to Cu excess. Identity of Czech tetraploid cultivar ??Unknown?? is also discussed.     

Meiosis and sexual fertility of autotetraploid clones of greater yam Dioscorea alata L.

Meiosis in the tetraploid (2n = 80) males of Dioscorea alata L. was investigated for the first time. During metaphase I, the chromosomes were associated mostly in 6–8 quadrivalents and the remaining ones as bivalents with no trivalents or univalents. Anaphase I and subsequent stages of meiosis were normal. The observation of quadrivalents in the tetraploids provides cytological evidence for autotetraploidy. The autotetraploid males and females were highly fertile and they produced viable seeds on artificial pollination. Pollination between diploids (2n = 40) and tetraploids (2n = 80) were also successful via embryo rescue, producing triploid (2n = 60) progenies. The discovery of fertile autotetraploids could initiate polyploidy breeding in D. alata by conventional hybridization for the first time. The reduced number of quadrivalents and the high fertility of the autotetraploids are thought to be the result of partial diploidization of meiosis. The findings also refute the assumption of the allopolyploid origin of D. alata from two putative progenitors.     

Ploidy levels of Dioscorea alata L. germplasm determined by flow cytometry

Dioscorea alata L. is a highly important crop, widely distributed in the humid and semi-humid tropics. Flow cytometry was used to determine the ploidy levels of 74 D. alata genotypes collected mainly from West African countries. Sixty three of the genotypes were found to be tetraploid, one was hexaploid and ten were octoploid. The high percentage of tetraploids together with the small percentage of hexaploid individuals and the absence of diploid individuals gives us some more clues on the possible origin of these species. No association between ploidy level and place of cultivation was found for the tested material. The obtained results represent important knowledge for enhancing the breeding methodologies and optimize germplasm management of this species. It also offers further insights to the phylogeny and evolution of Dioscorea species.     

Relationships among <Emphasis Type="Italic">Avena</Emphasis> species as revealed by consensus chloroplast simple sequence repeat (ccSSR) markers

Consensus chloroplast simple sequence repeat (ccSSR) makers were used to assess the genetic variation and genetic relationships of 80 accessions from 25 taxa of the genus Avena. Fifteen out of 16 ccSSR markers (93.75%) were polymorphic. A total of 51 alleles were detected at the 16 ccSSR loci. The number of alleles per locus ranged from 1 to 6, with an average of 3.2 alleles. Among these ccSSR loci, the highest polymorphism information content (PIC) value was 0.754, while the lowest PIC value was 0. The mean genetic similarity index among the 80 Avena accessions was 0.545, ranging from 0.188 to 1.000. To assess the usefulness of ccSSRs in separating and distinguishing between haplome (genome) groups, we used ordination by canonical discriminant analysis and classificatory discriminant analysis. Although discriminant analysis separated the haplome groups unequivocally, it was up to 69% predictive of correctly classifying an individual plant whose haplome(s) is unknown in the case where it belonged to the A haplome group, 75% where it belonged in the AC group, and almost 80% where it belonged in the ACD group. The analysis of genetic similarity showed that diploid species with the A haplome were more diverse than other species, and that the species with the As haplome were more divergent than other diploid species with the A haplome. Among the species with the C haplome, A. clauda was more diverse than A. eriantha and A. ventricosa. In the cluster analysis, we found that the Avena accessions with the same genomes and/or belonging to the same species had the tendency to cluster together. As for the maternal donors of polyploid species based on this maternally inherited marker, A. strigosa served as the maternal donor of some Avena polyploidy species such as A. sativa, A. sterilis and A. occidentalis from Morocco. A. fatua is genetically distinct from other hexaploid Avena species, and A. damascena might be the A genome donor of A. fatua. Avena lusitanica served as the maternal parents during the polyploid formation of the AACC tetraploids and some AACCDD hexaploids. These results suggested that different diploid species were the putative A haplome donors of the tetraploid and hexaploid species. The C genome species A. eriantha and A. ventricosa are largely differentiated from the Avena species containing the A, or B, or D haplomes, whereas A. clauda from different accessions were found to be scattered within different groups. Wei-Tao Li and Yuan-Ying Peng have contributed equally to this paper.     

Genetic variation within and among species of genus Arachis, section Rhizomatosae

The genus Arachis is endemic to South America and comprises 80 species, 69 of which have already been described and eleven not yet published. The genus includes the cultivated peanut (A. hypogaea) and several forage species, the most important ones being A. glabrata and A. pintoi. Accessions of section Rhizomatosae, including three tetraploid species 2n = 4x = 40 (A. glabrata, A. pseudovillosa and A. nitida nom. nud.) and one diploid species 2n = 2x = 20 (A. burkartii), were evaluated using RAPD markers to assay genetic variability within and among species. The ten random primers used yielded a total of 113 polymorphic bands. The data were scored as the presence or absence of each band in each sample. A distance matrix and dendrogram were obtained using Link's coefficient and the neighbor-joining method. Most accessions analyzed grouped into two major clusters: the first comprised most accessions of A. glabrata and accessions of A. nitida, and the second cluster comprised accessions of A. burkartii. Arachis pseudovillosa and a few accessions of A. glabrata and A. nitida were placed between these major clusters. The diploid and tetraploid species were grouped quite separately, suggesting that the tetraploids did not originate from the diploid species analyzed.     

Limited genotype- and ploidy-related variation in the nutritive value of perennial ryegrass (Lolium perenne L.)

Abstract

Water-soluble carbohydrates and fibre fractions are important traits that influence forage utilization by the ruminant. Little is known about the quality variation among perennial ryegrass genotypes within the same maturity group or between near-isogenic diploids and tetraploids. The current study was carried out in the form of two experiments on two successive years (2006–2007) in three sites in Northern Germany. The main aim was to investigate the variation in nutritive value that could be attributed to differences in maturity among 20 intermediate heading perennial ryegrass genotypes or to differences in ploidy between near-isogenic diploids and tetraploids. Results of the first experiment revealed significant variation among the 20 tested genotypes in the investigated quality parameters that were consistent with the discovered variation in the maturity of the genotypes determined in terms of their Mean Stage by Count (MSC). In the second experiment, few but consistent significant differences were detected between near-isogenic diploids and tetraploids. The tetraploid derivatives had always significantly higher water-soluble carbohydrate content and lower neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) than their near-isogenic diploid parents.     

Cytogenetic relationships between Avena insularis (2n=28) and both A. strigosa (2n=14) and A. murphyi (2n=28)

The newly discovered tetraploid oat Avena insularis was crossed with the diploid A. strigosa and the tetraploid A. murphyi. Considerably reduced chromosome association at meiosis and a low average number of chiasmata per cell of the A. strigosa × A. insularis hybrids indicated that the diploid A. strigosa did not participate in the creation of A. insularis. From A. murphyi, A. insularis differed by four chromosomal rearrangements and the hybrids between them were sterile. The tetraploids A. magna, A. murphyi and A. insularis share the two to four floret large diaspore, which is adapted to heavy alluvial soil. They all, however, diverge from one another by four chromosomal rearrangements. At this point it is not possible to determine whether they have diverged from a single tetraploid progenitor, or developed from different diploid species.     

Evaluation of geographic distribution of high-molecular-weight glutenin subunits (HMW-GS) in wild and cultivated Triticum species

Variation of high-molecular-weight glutenin subunit (HMW-GS) in 632 wild and cultivated Triticum accessions was investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. A total of 11 alleles of HMW-GS in diploid species, 22 in tetraploid species, and 15 in hexaploid species were detected. Diploid species on Glu-1A locus and tetraploid species Glu-1B locus showed the highest diversity, respectively. Tetraploid species had the highest level of diversity on three Glu-1 loci, followed by hexaploid and diploid, based on Shannon’s information index, Nei’s genetic diversity, and percentage of polymorphic loci. Molecular variance analysis confirmed main variance of HMW-GS within species, regions, and locations, respectively. Variance among species and regions was enhanced gradually with the increase of ploidy. Significant non-random distributions between the phylogenic trees of HMW-GS and the locations of accessions were tested by GenGIS software, indicated that geographic factors played an important role along the different orientations in the spread of Triticum species. We found one original diversified center in diploid what located around Elazig, Malatya, Gaziantep, Urfa, and Kiziltepe in Turkey, and three diversified centers in tetraploid wheat, including Turkey–Armenia–Georgia–Iran, Portugal–Spain, and Ethiopia, respectively, and two diversified adjacent areas between Turkey and Switzerland and around Turkey, Georgia, and Armenia. The original center of diploid species located in southeast Turkey, where the unexpressed 1Ay subunit was mainly distributed in T. urartu, could be one of the candidate regions of polyploidization of Triticum L. The regional distribution of HMW-GS and species also provided geographic evidences for the existence of founder effect on the spread of Triticum species. The present study suggests that integrating genetic diversity with geographic characterization in Triticum could very useful for collection, conservation, and utilization, as well as for research microevolution and domestication.     

High proportion of diploid hybrids produced by interspecific diploid × tetraploid <Emphasis Type="Italic">Sorghum</Emphasis> hybridization

A perennial version of grain sorghum [S. bicolor (L.) Moench] would create opportunities for greatly reducing tillage and preventing soil degradation. Efforts to select for perenniality and grain production among progeny of hybrids between S. bicolor (2n = 20) and the weedy tetraploid perennial S. halepense (L.) Pers. (2n = 40) are complicated in that F₁ hybrids produced by diploid × tetraploid sorghum crosses are usually tetraploid. In 2013, a set of random pollinations between 19 diploid cytoplasmic male-sterile inbred lines and 43 tetraploid perennial plants produced 165 F₁ hybrid plants, more than 75% of which had highly atypical plant, panicle, and seed phenotypes. Phenotypic segregation in F₂ populations derived from atypical hybrids was also anomalous. Examination of mitotic metaphase cells in F₁ or F₂ root tips revealed that 129 of the 165 hybrids were diploid. Parentage of the diploid progenies was confirmed using simple-sequence repeat analysis. The mechanism by which diploid hybrids arise from diploid × tetraploid crosses is unknown, but it may involve either production of monohaploid (n = 10) pollen by the tetraploid parent or chromosome elimination during early cell divisions following formation of the triploid zygote. The ability to produce diploid germplasm segregating for S. bicolor and S. halepense alleles could have great utility, both for the development of perennial sorghum and for the improvement of conventional grain sorghum.     

Geographical pattern and ploidy levels of the weed Solanum elaeagnifolium (Solanaceae) from Argentina

A total of 106 samples taken from natural Argentinean populations of the weedy Solanum elaeagnifolium (subgenus Leptostemonum) were studied cytologically to understand the impact of the different ploidy levels in its distribution and origin. Classical Feulgen staining was employed to determine mitotic chromosome numbers in all samples. 2C nuclear DNA content was determined by means of PI flow cytometry in eight samples of different ploidy levels. Principal component analysis and GIS tools were employed to compare altitude, annual precipitation and annual mean temperature among accessions. Three cytotypes were found: diploid (2n?=?24) which is widespread, tetraploid (2n?=?48) centered in western and southern Argentina, and hexaploid (2n?=?72) which predominates in central Argentina extending as well to the east. The annual precipitation is significantly different between tetraploids and hexaploids. Cx-values ranged from 1.231 to 1.275?pg, with statistical differences (of about 24.5–50.9?Mbp, p?≤?0.05) among accessions. Diploids are the most widespread cytotype and have adapted to a number of very different habitats. Tetraploids live in arid or semi-arid regions with a mean annual rainfall less than 500?mm. Hexaploids are successful in colonizing wetter areas, where no tetraploids were found. Thus, the distribution of cytotypes may be associated with habitat differences, particularly soil moisture. The observed cytotype pattern and the differences in DNA content suggest multiple places of origin for the polyploidy of S. elaeagnifolium in Argentina.