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1.
This paper presents the evaluation of genetic diversity in 29populations of wild taxa of theBrassica oleraceaL. group (2n=18)and two cultivars, using RAPDs as molecular markers. In a previouspaper (Lázaro and Aguinagalde,Annals of Botany82: 000–000,1998), 11 isozymes were used for the same purpose. Results obtainedwith the two molecular markers (isozymes and RAPDs) are compared.DNA from ten individuals per population was analysed using sixdifferent primers; the 151 detected bands were polymorphic,11 were common to all species, six to all taxa, only one toevery population; and no bands were shared by every individual.The dendrogram obtained using genetic distances clustersB. oleraceapopulationswithB. bourgeaui, B. alboglabra, B. montanaandB. incana. B.insularis, B. macrocarpa, B. villosaandB. rupestrispopulationsform another cluster. Populations ofB. creticaandB. hilarionisformthe third cluster. Genetic diversity inB. oleraceapopulations,theB. rupestriscomplex andB. creticasubspecies was estimatedusing the AMOVA programme; the latter was the most diverse.Copyright1998 Annals of Botany Company. Brassica oleraceaL., wild relatives, genetic diversity, genetic resources, RAPD markers, AMOVA.  相似文献   

2.
Sixteen seed accessions of four Brassica species (B. cretica,B. incana, B. montana and B. oleracea) were examined following5-22 years' storage in the germplasm bank. Germinability andisozyme of seeds stored under long-term (-10 °C and 3% moisturecontent) and short-term (5% °C and 8% moisture content)storage conditions were compared. Long-term storage producedno deterioration and the ability to germinate was satisfactorilymaintained over 8-22 years. Short-term storage conditions maintainedgermination ability up to 10-12 years in all accessions of B.cretica and B. montana. However, seed multiplication might beessential every 10 years for some accessions of B. oleraceastored in this way. In the 8 to 9-year-old accessions of B.cretica, B. incana and B. montana, no significant differenceswere detected between conservation systems for germinabilityand frequency of seeds showing isozyme activity for seven enzymesystems (ACO, IDH, MDH, ME, PGI, PGM and 6-PGD). However, significantdifferences were found for the ADH enzyme system. Moreover,in the 5-22-year-old B. oleracea accessions, significant differenceswere found between storage conditions with respect to isozymeactivity for all enzyme systems studied.Copyright 1995, 1999Academic Press Brassica cretica, Brassica incana, Brassica montana, Brassica oleracea, accessions, isozymes, germination, seed storage  相似文献   

3.
Three different types of epicuticular wax columns were foundinBrassicaspecies with a chromosome number (n)=9: long columns(LC), short columns (SC) and netted columns (NC). LC were foundinB. incanaandB. rupestris.SC were found inB. villosa, B. macrocarpa,B. cretica, B. hilarionisand also inB. montana. B. insulariscolumnswere intermediate. NC waxes were found inB. oleraceaand itsclose alliesB. alboglabraandB. bourgeaui.Samples ofB. rapa (n=10)andB.nigra (n=8)examined did not show any wax columns but their amphidiploidswithB. oleracea (B. napusandB. carinata,respectively) seemedto inherit the NC type of wax present inB. oleracea.Copyright1999 Annals of Botany Company Brassica, waxes, wax columns, leaf surface.  相似文献   

4.
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. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.  相似文献   

5.
We examined the genetic variation of 12 isozyme loci in 14 populations of Matthiola (Brassicaceae) representing the geographic distribution of the species M. incana, M. fruticulosa ssp. fruticulosa and M. tricuspidata in the Sicilian insular system and the adjacent mainland areas to estimate the levels and apportionment of genetic variation in the insular populations and to understand their population dynamics. The disparity in the distribution of polymorphism in populations of M. incana ssp. incana (low within populations but with high values of FST and GST) contrasts with the homogeneity in the inter-population distribution of the high genetic variation detected in M. tricuspidata and M. fruticulosa ssp. fruticulosa. While the low polymorphism found in M. incana ssp. incana is consistent with its origin through cultivation and the associated lack of gene flow, the Sicilian populations of the other two taxa probably derived from multiple founder events from nearby continental areas and, according to our estimates, have maintained high interpopulational gene flow. Unlike M. incana, the Sicilian populations of M. tricuspidata and M. fruticulosa ssp. fruticulosa could have survived the glaciations in refugia. This higher antiquity, together with the maintenance of abundant gene flow, largely explains their high values of genetic variation. In contrast, M. incana ssp. pulchella and M. incana ssp. rupestris have low indices of polymorphism and they are probably neo-endemics, as their distribution areas were severely affected by the Plio-Pleistocene glaciations.  相似文献   

6.
Understanding the evolutionary history of crops, including identifying wild relatives, helps to provide insight for conservation and crop breeding efforts. Cultivated Brassica oleracea has intrigued researchers for centuries due to its wide diversity in forms, which include cabbage, broccoli, cauliflower, kale, kohlrabi, and Brussels sprouts. Yet, the evolutionary history of this species remains understudied. With such different vegetables produced from a single species, B. oleracea is a model organism for understanding the power of artificial selection. Persistent challenges in the study of B. oleracea include conflicting hypotheses regarding domestication and the identity of the closest living wild relative. Using newly generated RNA-seq data for a diversity panel of 224 accessions, which represents 14 different B. oleracea crop types and nine potential wild progenitor species, we integrate phylogenetic and population genetic techniques with ecological niche modeling, archaeological, and literary evidence to examine relationships among cultivars and wild relatives to clarify the origin of this horticulturally important species. Our analyses point to the Aegean endemic B. cretica as the closest living relative of cultivated B. oleracea, supporting an origin of cultivation in the Eastern Mediterranean region. Additionally, we identify several feral lineages, suggesting that cultivated plants of this species can revert to a wild-like state with relative ease. By expanding our understanding of the evolutionary history in B. oleracea, these results contribute to a growing body of knowledge on crop domestication that will facilitate continued breeding efforts including adaptation to changing environmental conditions.  相似文献   

7.
《Flora》2014,209(12):733-741
Inter-Simple Sequence Repeat (ISSR) molecular markers and morphological analysis were used in order to characterize wild populations and cultivated forms of orphan crop species Capparis spinosa L. in a Mediterranean island complex. Nineteen wild populations belonging to two different subspecies, C. spinosa subsp. spinosa and subsp. rupestris, were sampled in different environments in Sicily and the surrounding islets Lampedusa, Pantelleria and Salina. Different biotypes cultivated in Pantelleria and Salina were analysed. Six ISSR primers were selected for genetic characterization, and all clear and reproducible bands were scored and analysed. Among the 47 ISSR bands obtained, 97.5% were polymorphic. Results of AMOVA and STRUCTURE analysis suggested a clear genetic distinctness between subspecies at the regional level and suggested the existence of two taxonomic groups among wild populations, with different ecological preferences and distinctive morphological characters. Cultivated forms showed genetic affinity to subsp. rupestris. ISSR analysis not only provided specific molecular markers to discriminate the taxa, but also proved useful in supporting the hypothesis of a hybrid origin of the intermediate phenotypes found in overlapping distribution areas. The identified molecular markers provided a basic tool for the DNA fingerprinting of wild and commercial capers in the Mediterranean region and nearby territory.  相似文献   

8.
Strict sterility barriers where found between theScutellaria populations on Sicily and the Greek populations. The material from Samos is separated by a strict sterility barrier from the other Greek populations. In contrast, the populations on mainland Greece and adjacent islands are all ± interfertile. Three species are recognized,S. rubicunda Hornem., endemic to Sicily, andS. brevibracteata subsp.icarica, endemic to Samos and Ikaria. All other populations are referred toS. rupestris with eight subspecies, most of which are endemic to one island or to one mountain. Three new subspecies are described, viz. subsp.rechingeri and subsp.olympica, endemic to mt Vourinos and mt Olympus in North Greece, respectively, and subsp.caroli-henrici, native to the Malea peninsula of Peloponnisos. The phytogeographical connections and genetic differentiation within and between populations are discussed.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday.  相似文献   

9.
The eastern‐Mediterranean Abies taxa, which include both widely distributed species and taxa with minuscule ranges, represent a good model to study the impacts of range size and fragmentation on the levels of genetic diversity and differentiation. To assess the patterns of genetic diversity and phylogenetic relationships among eastern‐Mediterranean Abies taxa, genetic variation was assessed by eight nuclear microsatellite loci in 52 populations of Abies taxa with a focus on those distributed in Turkey and the Caucasus. Both at the population and the taxon level, the subspecies or regional populations of Abies nordmanniana s.l. exhibited generally higher allelic richness, private allelic richness, and expected heterozygosity compared with Abies cilicica s.l. Results of both the Structure analysis and distance‐based approaches showed a strong differentiation of the two A. cilicica subspecies from the rest as well as from each other, whereas the subspecies of A. nordmanniana were distinct but less differentiated. ABC simulations were run for a set of scenarios of phylogeny and past demographic changes. For A. ×olcayana, the simulation gave a poor support for the hypothesis of being a taxon resulting from a past hybridization, the same is true for Abies equi‐trojani: both they represent evolutionary branches of Abies bornmuelleriana.  相似文献   

10.
We studied degree of variability and relationships among populations belonging to five species of the section Strombocarpa of the family Leguminosae, namelyProsopis ferox, P. torquata, P. pubescens, P. strombulifera andP. reptans, by isozyme electrophoresis. The genetic similarity betweenP. reptans andP. strombulifera is high enough for the two to be considered subspecies or geographic races ofP. strombulifera instead of good taxonomic species. As expected these species cluster withP. pubescens, all belonging to series Strombocarpae. This group is different isoenzymatically from the remaining species,P. torquata andP. ferox. Comparison of our results with those obtained earlier for species of the section Algarobia showed that genetic variability in the section Strombocarpa is lower than in the section Algarobia, while the species divergence is much higher. These results suggest different adaptive strategies between these sections.  相似文献   

11.
As part of a project aimed at investigating the Matthiola taxa endemic to Sicily (Italy), this study focused on Matthiola incana, an edible species used in the traditional medicine of various countries. Herein, the characterization of phenolic and volatile compounds, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe2+ chelating activity assays) and the toxicity test (Artemia salina lethality bioassay) of the hydroalcoholic extracts from the aerial parts of M. incana subsp. rupestris from Mt. Pellegrino (Palermo) and Mt. Erice (Trapani), and of M. incana subsp. pulchella are reported. The results are compared with those previously shown for M. incana subsp. incana, to achieve a comprehensive overview of the three subspecies. The HPLC-PDA/ESI-MS and SPME-GC/MS analyses led to the identification of 13 phenolics and 54 volatile compounds. Differences in the qualitative-quantitative profile of these phytochemicals have been highlighted between the M. incana subspecies. The antioxidant tests showed different activity for the extracts, which were found to possess better chelating properties. At last, none of the tested extracts displayed toxicity against brine shrimp larvae. These findings enrich the knowledge on the Matthiola taxa growing wild in Sicily, both from the strictly systematic point of view and for the possible applications as sources bioactive compounds that can be used in the nutraceutical field.  相似文献   

12.
Chloroplast DNA (cpDNA) and isozyme variation were analyzed over a range of populations of two infraspecific taxa of the tetraploidSenecio vulgaris. The isozyme data were supportive of the hypothesis that the weedy and cosmopolitanS. vulgaris var.vulgaris is an evolutionary derivative ofS. vulgaris subsp.denticulatus from the coasts of W Europe and montane altitudes in S Spain and Sicily. The two taxa exhibited a very high genetic identity with subsp.denticulatus containing slightly more isozyme diversity than was found in var.vulgaris. — Three cpDNA haplotypes (A, B, C) already known from other Mediterranean diploid species ofSenecio were resolved in var.vulgaris, and an additional fourth haplotype (E) was found in subsp.denticulatus. Two alternative hypotheses were chosen to account for the origin and maintenance of the observed cpDNA composition ofS. vulgaris. It either reflects (1) the retention of an ancestral polymorphism which stems from the recurrent and polytopic formation of ancestral tetraploid lineages; or (2)S. vulgaris originally was characterized by haplotype E, and haplotypes A, B and C were acquired through repeated introgressive hybridization with related diploid species. The finding that very low levels of nuclear (isozyme) diversity were present in both taxa ofS. vulgaris examined supports the second of these two hypotheses; however, more detailed analysis of nuclear genetic diversity is required before a firm conclusion can be reached on this matter.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday  相似文献   

13.
Allozyme electrophoresis was used to study genetic diversityamong populations of the freshwater, hermaphroditic snail Biomphalariacamerunensis in Cameroon. Five of 19 loci studied in 15 enzymesystems were polymorphic. Intrapopulation variation was evidentin 8 of 12 populations sampled and heterozygotes were presentin 6 of these. Two populations with large sampled sets werepanmictic. Although results for the remaining 4 populationswith heterozygotes present were inconclusive, our findings supportthe hypothesis that Biomphalaria are out-breeders. The allelesfor two loci, asparate aminotransferase-1 (AAT-1) and 6-phosphogluconatedehydrogenase (6-PGD), showed distribution patterns that suggestthey may be limited by climate or habitat. The slow migratingAAT-1 was the only allele found in the mountainous regions ofthe southwest. This region falls under the Cameroon-type climateand is the wettest region in the country. The faster allelewas restricted to the lowland rain forest of the south. For6-PGD the fast allele was found throughout the range of B. camerunensis,but the slower allele was found only in the mountainous regionswithin the Cameroon-type climate. (Received 27 April 1989; accepted 9 September 1989)  相似文献   

14.
Abstract

Brassica rupestris Raf. is a chasmophyte species that includes two subspecies, both endemic to Central-Western Sicily (Italy). Inter-Simple Sequence Repeat (ISSR) markers were used to detect genetic diversity within and among eight populations representative of the species' distribution range. High levels of genetic diversity were revealed both at the population (PPB = 53.88%, H S = 0.212, Sh = 0.309) and at the species level (PPB = 96.55%, H T = 0.307, Sh = 0.464). The correlation between genetic and geographical distances was negative (Mantel test, r = ?0.06, P < 0.95). The two subspecies of B. rupestris, subsp. rupestris and subsp. hispida, showed remarkable genetic similarity and molecular data did not unequivocally support their distinctness. The pattern of genetic variation revealed by our study bears important consequences for conservation management: It is desirable to preserve B. rupestris populations in situ with a “dynamic” strategy, while, ex situ conservation programmes might be improved to safeguard maximum genetic diversity.  相似文献   

15.
Dioecy, the separation of sexes, has arisen independently many times in the course of angiosperm evolution. Avoidance of inbreeding is clearly involved in the evolution of dioecy, and as a consequence we predict that dioecious populations should maintain higher levels of genetic variation than closely related nondioecious populations. We tested that prediction by comparing allozymic variation in two closely related taxa, the monoecious and dioecious subspecies of the Mediterranean cucurbit, Ecballium elaterium. Thirteen polymorphic loci were screened for seeds sampled from 10 monoecious and 13 dioecious populations spanning the geographic ranges of the subspecies in Spain. The dioecious subspecies showed strikingly greater allelic diversity and heterozygosity than the monoecious subspecies. A hierarchical F-statistic analysis clearly demonstrated considerable genetic variation within populations for the dioecious populations, whereas for the monoecious populations almost all genetic variation resulted from differences among populations. The general pattern of homozygosity within monoecious populations suggests that they are highly inbred. In order to assess historical influences on current patterns of genetic variation, we conducted a genetic-distance analysis. The observed relationship between genetic distance and geographic distance between populations supports the hypothesis that the subspecies' current allopatric distributions on the Iberian Peninsula are the result of separate waves of colonization from the north (monoecious) and south (dioecious).  相似文献   

16.
Data are presented on genetic variation at 27 enzyme loci of the Green-Winged orchid,Orchis morio, in 18 population samples from Italy. The existence in Italy of two subspecies, i.e. subspp.morio andpicta, is not supported by allozyme data. No genetic heterogeneity was found betweenmorio-like andpicta-like samples and specimens. Moreover, morphological transition between the two forms was observed in different Italian populations. The parameters of genetic variability estimated forO. morio populations are consistent with those found among monocotyledon plants, and among those outcrossing, animal-pollinated and with wind-dispersed seeds. Genetic diversity of ItalianO. morio is mostly within populations. Correspondingly, low values of interpopulational genetic distance were found. This appears to be due to high levels of gene flow, which were estimated with different methods. The lack ofO. longicornu from Italian samples, as well as of any hybrid withO. morio (F1, backcrossed or recombinant individuals) is demonstrated on the basis of genetic data. It is concluded that recurrent reports ofO. longicornu from Italy are due to confusion withO. morio or with otherOrchis species.  相似文献   

17.
There is controversy about the phylogenetic relationships betweenIberus gualtieranus and I. alonensis. Some authors considerthem as valid species or subspecies while others believe thatthe flattened shell of I. gualtieranus is an ecotypic adaptationto dry karstic environments. Two fragments of the mitochondrialDNA (partial COI and 16S rRNA) were sequenced and used in maximumparsimony, maximum likelihood and neighbour-joining analyses.Iberus alonensis show two distinct lineages, one from Almeríaand the other one from Granada and Jaén-Córdobaregions. Iberus gualtieranus populations are recovered as aterminal node within the I. alonensis group from Almería.The I. gualtieranus clade shows a polytomy and there are nodifferences between the populations of the three isolated localitieswhere I. gualtieranus is currently distributed. This indicatesthat the geographical isolation of these populations has notresulted in genetic diversification. The results indicate thatthe population of I. gualtieranus from Sierra de Gádorin Almería is the only autochthonous one, while the othertwo populations originated by historical introductions. On thebasis of the differences in shell morphology, together withthe presence of a hybrid zone connecting both taxa in nature,and the possibility of obtaining fertile hybrids under laboratoryconditions, we conclude that these two taxa represent two subspecies:Iberus gualtieranus gualtieranus and I. gualtieranus alonensis. (Received 27 September 2004; accepted 10 March 2005)  相似文献   

18.
Bromus hordeaceus (sectionBromus, Poaceae), a predominantly self-fertilizing tetraploid (2n=28), is an annual weed native to the Mediterranean Basin, which now has a world-wide distribution. High morphological variation led to the recognition of four subspecies, three of which correlated with habitat-type. We examined genetic diversity at enzyme loci in 15 populations from the Mediterranean and the Atlantic region. Although sampled over a larger range of ecological and geographical conditions, the North-African populations appeared less genetically differentiated than populations from Brittany, suggesting higher levels of gene flow among the first ones (Nm=3.756 and 1.066 respectively). No genetic differentiation was encountered among the four subspecies. The populations were homozygous at homologous loci, suggesting high rates of selfing, but they frequently exhibited fixed intergenomic heterozygosity. The meiotic chromosome behaviour and disomic inheritance encountered are in accordance with the previously proposed allopolyploid origin of the species. The diploidsB. arvensis andB. scoparius have been previously implicated in the parentage ofB. hordeaceus on the basis of morphology and serology. We comparedB. hordeaceus with related diploid species belonging to the same section (sectionBromus) using different sources of data (flow cytometry, karyotypes, RAPD and DNA sequences). Molecular phylogeny based on internal transcribed spacer sequences of nuclear ribosomal genes provided the first clear scheme of relationships among monogenomic species of the section. A new hypothesis is proposed concerning the origin ofB. hordeaceus: We found that it diverged earlier than all other species of sectionBromus excluding the diploidB. caroli-henrici which is basal in this group. The 13 autapomorphies accumulated byB. hordeaceus, and the absence of intra-individual sequence heterogeneity are also consistent with the relatively ancient origin of the species within the section.  相似文献   

19.
Brassica incana is a secondary-gene pool wild relative of Brassica oleracea. Twenty-two B. incana populations are recorded in Italy, where the species has recently been pointed out as in priority need of conservation. While data on the spatial and temporal variation of B. incana Italian populations are completely lacking, this information is useful in conservation planning for this species. Three populations from the Sorrento peninsula and from the islands of Ischia and Capri, collected in 1984 and 2012, were characterised for 12 morpho-phenological and 21 genetic traits to assess their spatial–temporal variation. The populations were quite different for morpho-phenological and genetic traits. Spatial differentiation was high and easily explained by the isolation. Temporal differentiation between the Sorrento and Ischia populations was high and explained by a reduction in the population census across time, while it was not significant between the two Capri accessions as such pointing to a major effect of genetic drift. Numerical dimension is extremely relevant in evaluating conservation priorities since it has a major impact on population dynamics over time. The Sorrento and Ischia populations are under threat and urgently need conservation actions, suggesting an alarming scenario for the survival of other crop wild relative populations which are similar in census. Our data also show that, in an allogamous and self-incompatible species like B. incana, populations of 100–200 individuals maintain high allelic diversity. According to obtained results, natural populations of species with similar reproductive system and census can be considered at low risk of genetic erosion.  相似文献   

20.
中国松毛虫属八个种和亚种亲缘关系的DNA指纹证据   总被引:14,自引:1,他引:14  
利用DNA指纹谱方法探讨了中国松毛虫属8个种和亚种〔马尾松毛虫Dendrolimus punctatus punctatus (Walker),德昌松毛虫D. punctatus tehchangensis Tsai et Liu,文山松毛虫D. punctatus wenshanensis Tsai et Liu,思茅松毛虫D. kikuchii Matsumura,赤松毛虫D. spectabilis Butler,油松毛虫D. tabulaeformis Tsai et Liu,落叶松毛虫D. superans (Butler),云南松毛虫D. houi Lajonquiere之间的亲缘关系。13个随机引物在8种松毛虫中共检测到168个多态分子标记。分析表明,这8个种间的遗传距离的变化范围为0.3780~0.7360;马尾松毛虫与其亚种德昌松毛虫的遗传距离最近,为0.3780,与其另一亚种文山松毛虫以及油松毛虫的遗传距离次之,皆为0.5233;赤松毛虫、落叶松毛虫、云南松毛虫与马尾松毛虫的遗传距离则再次之,分别为0.6362,0.6770和0.6944;与马尾松毛虫遗传距离最远的是思茅松毛虫,为0.7360。8种松毛虫间具体的亲缘关系为: (D. superans (D. tabulaeformis (D. p. wenshanensis (D. p. tehchangensis, D. p. punctatus)(D. Kikuchii (D. spectabilis, D. houi))。  相似文献   

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