共查询到20条相似文献,搜索用时 15 毫秒
1.
Cahill P. Joseph 《Genetic Resources and Crop Evolution》2004,51(7):773-781
Chia, Salvia hispanica L., was a staple crop in pre-Columbian Mesoamerica. Despite the great potential of the species as an oilseed crop, little research related to domesticated and wild varieties exists. A study was undertaken to assess genetic diversity among 38 wild and domesticated accessions of S. hispanica collected throughout Mesoamerica by using RAPD markers. Genetic diversity was higher among wild varieties (H
G= 0.15) than all domesticated varieties (H
G= 0.10) and modern commercial domesticated varieties (H
G= 0.02), suggesting a slight loss of diversity accompanying domestication and a near lack of diversity in modern commercial varieties. In addition, the preliminary results indicate that the center of genetic diversity is in the highlands of western Mexico. 相似文献
2.
Liang Liao Tongjian Li Jin Zhang Lingling Xu Huisheng Deng Xingjie Han 《Genetic Resources and Crop Evolution》2014,61(1):55-67
Ramie (Boehmeria nivea) was domesticated in China. However, the geographic region of domestication is not exactly known. Genetic diversity and population structure of ramie and their wild relatives were assessed using microsatellite markers. The 8 microsatellite primers revealed 96 alleles in 50 ramie populations, with an average of 10.25 alleles per locus. Cultivated ramie gene pool harbors approximately 82.9 % of the SSR diversity presented in wild B. nivea var. nivea. It is suggested that ramie has experienced a relatively moderate domestication bottleneck. The distribution of genetic diversity shows that genetic diversity is relatively high in populations along the Yangtze River compared to the peripheral ones. The scatter plots of principal coordinates analysis indicated that there are three well-supported varieties in B. nivea. The NJ tree and the distribution of genetic diversity showed that ramie has been domesticated in the middle and lower regions of the Yangtze valley, and populations in Sichuan province have been introduced from this region, forming naturalized populations. 相似文献
3.
Ken Oyama Sergio Hernández-Verdugo Carla Sánchez Antonio González-Rodríguez Pedro Sánchez-Peña José Antonio Garzón-Tiznado Alejandro Casas 《Genetic Resources and Crop Evolution》2006,53(3):553-562
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. 相似文献
4.
R. H. Andueza-Noh M. L. Serrano-Serrano M. I. Chacón Sánchez I. Sanchéz del Pino L. Camacho-Pérez J. Coello-Coello J. Mijangos Cortes D. G. Debouck J. Martínez-Castillo 《Genetic Resources and Crop Evolution》2013,60(3):1069-1086
The Mesoamerican (MA) gene pool of lima bean (Phaseolus lunatus L.) is widely distributed from northern Mexico to northern Argentina in its wild forms and from the southern United States to the east coast of Brazil in its domesticated forms. This broad distribution and lack of wild accessions of the MA gene pool in many areas of its natural distribution has impeded determining its center of domestication and establishing whether it has a single or multiple centers. To answer these questions, we evaluated 262 accessions of P. lunatus using two intergenic spacers of chloroplast DNA: atpB-rbcL and trnL-trnF. The data were analyzed using a maximum likelihood tree (ML), a haplotype network and two estimators of genetic differentiation (N ST and G ST). Nucleotide diversity (π) and haplotype (Hd) were quantified to estimate the percentage of reduction in genetic diversity (%r) as a founder effect. The ML tree and haplotype network indicated the existence of three groups (AI, MI and MII), which was supported by the high values of N ST (0.61–0.80). Values for %r were high (58.67–60.83 %). Existence of Mesoamerican and Andean gene pools was confirmed, with two genetically and geographically distinct groups (MI and MII) within the MA gene pool. We present the first evidence for multiple origins of domestication for the MA gene pool. For MI, we propose western central Mexico as the domestication area and between Guatemala and Costa Rica for MII. We observed a founder effect in the MA gene pool as a result of domestication. 相似文献
5.
S. Gopala Krishnan N. K. Dwivedi J. P. Singh 《Genetic Resources and Crop Evolution》2011,58(7):961-966
Crop domestication has lead to the selection of a wide range of traits that distinguish domesticated crops from their wild
ancestors. Over the past four decades, concerted efforts by archaeologists and geneticists have provided novel insights into
the domestication of crops. However, minor crops are rarely a subject for intensive domestication studies and very less is
known on the domestication of guar [Cyamopsis tetragonoloba (L.) Taub.] except the trans-domestication hypothesis. The hypothesis proposes that the domestication of guar took place
in recent times in the dry areas of the northwestern region of Indo-Pakistan subcontinent and the African wild species, C. senegalensis Guill. et Perr., as its ancestor. However, the process by which the wild species was domesticated is not fully understood.
The present paper describes the exploration, collection and in situ characterization of the primitive weedy forms of guar that could be the missing link between the wild and cultivated species.
Adak guar is found to grow along with cultivated guar as a weed and is characterized by several primitive characters, prominent
among which are spreading habit, small inedible pods which shatter at maturity, hard seed coat and seed dormancy. A total
of 66 germplasm collections of these primitive weedy forms of guar have been made from naturally occurring populations in
the arid regions of northwestern India. Systematic studies involving these primitive weedy forms can help in understanding
the domestication bottlenecks and in utilizing the genetic variation lost during the process of domestication for the improvement
of cultivated guar. 相似文献
6.
D. Arias J. Peñaloza-Ramírez O. Dorado P. Cuevas-Reyes Esaú Leyva Ana Luisa Albarrán-Lara G. Rangel-Altamirano 《Genetic Resources and Crop Evolution》2010,57(8):1227-1238
Jacaratia mexicana A. DC. (Caricaceae) is a tropical tree distributed throughout Mexico and Mesoamerica. Some evidence in Mexico indicates the
presence of an incipient domestication process in this species. Phylogeographical analyses can potentially determine contemporary
patterns of gene flow, isolation between population lineages, as well as historical processes such as population bottlenecks
or expansions on their geographical areas. In this study we reconstruct the phylogeographical patterns in populations of J. mexicana A. DC., in order to find differences between genetic variation among wild and cultivated populations utilizing chloroplast
DNA and nuclear DNA sequences. We generate a Bayesian phylogenetic tree, to estimate the divergence time between clades using
calibrated mutation rates. We also infer the demographic history of these populations using neutrality tests among wild and
cultivated accessions. We identified higher levels of haplotype and nucleotide diversity for the cpDNA and ITS types in wild
populations than in domesticated populations. These results indicate a reduction of genetic diversity derived from human selection
on domestication traits. Neutrality test suggests population expansion detected by the significant negative values of Fu’s
Fs in the cultivated populations of this specie. These process results in an excess of rare polymorphism with the fixation
of certain advantageous mutation throughout time, this implication are in accordance with the role of the strong selection
in the fruit traits of J. mexicana. The dated phylogeny constructed with BEAST program indicated a dispersion pattern for the J. mexicana ancestors across the South Pacific and South Eastern populations during the late Pliocene. Posterior dispersion and divergence
in the clades from Central Mexico and North Pacific are in agreement with the episodes of mountain-building in different regions
of Mexico. 相似文献
7.
The present study, using RAPD analysis, was undertaken to characterize genetic variation in domesticated cowpea and its wild progenitor, as well as their relationships. The materials used consisted of 26 domesticated accessions, including accessions from each of the five cultivar-group, and 30 wild/weedy accessions, including accessions from West, East and southern Africa. A total of 28 primers generated 202 RAPD bands. One hundred and eight bands were polymorphic among the domesticated compared to 181 among wild/weedy cowpea accessions. Wild accessions were more diverse in East Africa, which is the likely area of origin of V. unguiculata var. spontanea. Var. spontanea is supposed to have spread westward and southward, with a loss of variability, loss counterbalanceed in southern Africa by introgressions with local perennial subspecies. Although the variabilty of domesticated cowpea was the highest ever recorded, cultivar-groups were poorly resolved, and several results obtained with isozyme data were not confirmed here. However primitive cultivars were more diverse than evolved cultivars, which still suggests two consecutive bottlenecks within domesticated cowpea evolution. As isozymes and AFLP markers, although with a larger number of markers, RAPD data confirmed the single domestication hypothesis, the gap between wild and domesticated cowpea, and the widespread introgression phenomena between wild and domesticated cowpea. 相似文献
8.
Leila Riahi Nejia Zoghlami Alexandre Fournier-Level Alexis Dereeper Loïc Le Cunff Valérie Laucou Ahmed Mliki Patrice This 《Genetic Resources and Crop Evolution》2013,60(3):1139-1151
In this study, two gene fragments corresponding to the VvMYBA1 and VvMYBA2 loci were sequenced on a sample of grapes including cultivated and wild accessions originating from Tunisia, Germany and France. A total of 42 SNPs were detected in the sequenced fragments giving an average of 1 SNP every 33 bp. High level of polymorphism was observed in the samples either in cultivated or wild accessions. Pattern of nucleotide diversity indicates a non departure from neutrality expectations for wild grapevine sample for gene VvMYBA1 and VvMYBA2 and for cultivated sample for gene VvMYBA1. However, a linkage to a selective sweep was revealed for cultivated grapevine gene pool in gene VvMYBA2. A genetic structure of the studied sample according to accession taxonomic status was revealed by the UPGMA clustering with a considerable overlap. This result was confirmed by significant but low genetic differentiation values between cultivated and wild sample. The number of migrants Nm based on sequence data information between Tunisian cultivars and Tunisian wild accessions showed a low level of gene flow between those germplasms. This finding indicates that Tunisian cultivars do not derive directly from local wild populations but could mostly correspond to imported materials introduced during historical times. However, the possibility that some cultivars derived from ancestral events of local domestication or cross hybridization with native wild plants was not completely excluded for Tunisian grapevine accessions. 相似文献
9.
Thus far, there is little knowledge of the genetic diversity, structure and gene flow dynamics in rare wild and semi-wild soybean mixed populations, and such information is vital for understanding of the origin of semi-wild soybean (Glycine gracilis) and the biosafety protection of wild soybean from transgenic soybeans. Population eco-genetic data are necessary to provide a more coherent and comprehensive understanding of the genetic events that occurred in the natural habitats of wild soybean (Glycine soja). We tested genetic diversity and structure of 11 wild mixed populations of wild soybean (Glycine soja) and semi-wild soybean (G. gracilis), 1 wild soybean population, and 1 cultivated soybean variety population were studied using 20 nuclear microsatellite markers (SSRs). We found based on microsatellite polymorphisms that the mixed populations were characterized by higher mean heterozygosity (H o = 0.029) and outcrossing rate (t m = 6.35 %), and lower fixation index (F is = 0.891), and the semi-wild plants had distinctly higher heterozygosity (H o = 0.081) than that of the wild plants (H o = 0.007). The occurrence of semi-wild plants influenced population genetic structure but not geographical population differentiation. These mixed populations exhibited strong ecogeographical differentiation, which suggests that their original populations were colonized over a long phytogeographical history. The introgression occurred through pollen gene flow from the soybean fields into wild populations and created the semi-wild plants, with significant genetic differentiation from the typical wild ones. Introgressive genes could become established by two possible modes in wild soybean populations by both self-segregation and/or intrapopulation secondary hybridization. The latter deserves attention because of the possibility of rapid transgene escape. 相似文献
10.
S. K. Malik Susheel Kumar I. P. Singh O. P. Dhariwal Rekha Chaudhury 《Genetic Resources and Crop Evolution》2013,60(5):1655-1671
Northeast India is rich in Citrus genetic diversity representing several wild and cultivated species. Besides commercially cultivated species, several wild, semi-wild and domesticated species namely Citrus indica, C. macroptera, C. ichangensis, C. latipes, C. megaloxycarpa and C. assamensis are found to grow in Northeast India. These species have great potential in improvement of Indian Citrus industry being source of genes for combating biotic and abiotic stresses. The natural diversity of these genetic resources is shrinking at alarming rate due to large scale deforestation, shifting cultivation practiced in these areas and climate change scenario in this important hotspot of biodiversity. Socio-economic importance of each species have been studied during surveys and interesting domestication trends were observed based on their cultural and economic significance, which led to “in situ on farm” conservation of C. indica, C. macroptera and threat to C. megaloxycarpa and C. ichangensis. Consequently, genetic resources of most of these species are facing severe threat of extinction necessitating policy interventions and adoption of dynamic conservation and management strategies. Species specific conservation strategy especially through “in situ on farm” conservation has been proposed with suitable sites in Northeastern Indian states based on population structure and suitability of habitat. Farmers’ support through “The Biological Diversity Act, 2002” and “The Protection of Plant Varieties and Farmers’ Rights Act, 2001” of India would bring the required impact on management of these complex genetic resources of Citrus. In the present study, we have documented the current status, socio-economic potential, domestication trends and associated traditional knowledge of these wild and semi-wild Citrus species occurring in Northeast India and enumerated suitable conservation strategies and desired policy interventions for their dynamic conservation and sustainable utilization. 相似文献
11.
A number of genes that contribute to the domestication traits of cultivated rice have been identified. These include Sh4, Rc, PROG1 and LABA1, which are associated with non-shattering rachis, white pericarp, erect growth and barbless awns, respectively. The mutations giving rise to the “domestication alleles” of these genes are either invariable in cultivated rice, or have variability that is strictly associated with the phenotypic trait. This observation forms the basis to those current rice domestication models that envisage a single origin for the domesticated phenotype. Such models assume that the domestication alleles are absent or rare in wild rice, emerged under cultivation and spread across all rice groups by introgressive hybridization. We examined whole-genome sequencing datasets for wild and cultivated rice to test the former two assumptions. We found that the rc and laba1 alleles occur in wild rice with broad geographical distribution, and reach frequencies as high as 13 and 15%, respectively. These results are in agreement with previous observations of the prog1 and sh4 domestication alleles in wild populations. We also show that the diversity of the genomic regions surrounding the rc, laba1, prog1 and sh4 alleles in wild accessions is greater than that in cultivated rice, suggesting that these alleles emerged prior to domestication. Our findings indicate that the possibility that independent rice groups obtained identical domestication alleles directly from the wild population needs to be considered. 相似文献
12.
Carlos Navea Teresa Terrazas Alfonso Delgado-Salinas Porfirio Ramírez-Vallejo 《Genetic Resources and Crop Evolution》2002,49(2):125-132
It is surmised that domestication has reduced geneticvariability in the common bean (Phaseolusvulgaris L.). However, little is known about leaf anatomy responses to water stress in wild or domesticated forms ofP. vulgaris. In this study,anatomical variation was evaluated in watered and water stressed plants of wild and domesticated genotypes of P.vulgaris from Mexico, growing under greenhouse conditions. Five terminal leaflets of completely expanded leaves wereused to evaluate leaf area (LA) and theirmiddle-regions to evaluate leaf thickness (LT), and various anatomical features. Domesticated genotypes showed bigger LAthan that of the wild ones; there was an effect due to the origin of materials, LA being bigger in genotypes from warm and humid lands that those from dry and temperate ones. No differences were detected in LT among materials; however, in domesticated plants the palisadeparenchyma predominated over the spongy one, contrasting with thewild genotypes. Under drought conditions, stomatal abortion was observed in wild and domesticated genotypes, especially on theabaxial surface. We conclude that, in fact, there are contrasting differences in leaf anatomy among wild and domesticated forms of Mexican Phaseolus vulgaris. Results suggest that domestication not only favours the enlargement of the LA, but also an increase in palisade parenchyma, suggesting a divergence toward assimilation in domesticated forms, in contrast with a better internal gas diffusion in wild forms. Domestication seems to have accentuated stomatal abortion as means of a transpirational control mechanism to counteract the effects of drought. 相似文献
13.
Gabriella Sonnante Anna Vittoria Carluccio Roser Vilatersana Domenico Pignone 《Genetic Resources and Crop Evolution》2007,54(3):483-495
The evolutionary history of artichoke and cultivated cardoon and their relationships to wild allies of the genus Cynara are not fully understood yet. To try resolve the evolutionary patterns leading to the domestication of these two crops, a
study of molecular evolution was undertaken. The species C. cardunculus, including artichoke, cultivated and wild cardoon, together with four wild Cynara species were taken into consideration. Internal (ITS) and external (ETS) rDNA transcribed spacers were used as markers of
nuclear genome, the psbA-trnH spacer as a marker of chloroplast genome. Sequences were analysed using phylogenetic analysis packages. Molecular data indicate
that the whole genus is quite recent and that the domestication of artichoke and cultivated cardoon, crops diverging for reproduction
system and use, are independent events which diverge in time and space. As for wild Cynara species, an evolutionary pattern consistent with their present geographical distribution was hypothesized in relation to
the climatic changes occurring in the Mediterranean during the last 20 millennia: C. humilis and C. cornigera appeared to have differentiated first, C. syriaca and C. baetica were differentiated in a second period, while C. cardunculus showed to be the most recent and plastic species. The high plasticity of C. cardunculus has not only allowed its nowadays wide distribution, but has also given the potential for domestication.
Dedicated to the memory of Richard Neville Lester (1937–2006) who greatly contributed to the understanding of the evolution,
domestication, and genetic resources of eggplants as well as to the biosystematics and taxonomy of allied species.
IGV Publication N. 78 of the Institute of Plant Genetics, CNR 相似文献
14.
Elena Albrecht Dapeng Zhang Robert A. Saftner John R. Stommel 《Genetic Resources and Crop Evolution》2012,59(4):517-538
Capsicum baccatum is one of five domesticated pepper species which, despite its morphological and ecological variability, has been underexploited
for germplasm improvement. Utilizing a broad spectrum of domesticated and wild C. baccatum germplasm, we utilize AFLP markers to describe the species’ molecular diversity and population structure in the South American
gene pool. Analysis of molecular variance (AMOVA) revealed greater genetic diversity in the wild form of C. baccatum (C. baccatum var. baccatum) than in the domesticated form of the species (C. baccatum var. pendulum). Both Bayesian and distance based clustering analysis, as well as principal coordinates analysis (PCA), concordantly demonstrated
admixture/shared ancestry between wild and cultivated C. baccatum botanical varieties. Two principal genetic groups were identified in the domesticated C. baccatum accessions largely based on their geographic distribution in South America. One group was predominated by accessions from
the western territories of the species’ distribution (Peru, Colombia, Ecuador, Bolivia, Chile and northwestern Argentina)
and the second by accessions from the eastern regions, Paraguay and eastern Argentina). The two genetic groups overlapped
in the geographic location of present-day Bolivia. The grouping pattern suggested that C. baccatum was domesticated in multiple sites and that its evolution took two lineages followed by lineage differentiation. The wild
accessions most closely related to the cultigens were found in the highlands of Peru and Bolivia, which support the early
hypothesis that this region is one of the domestication sites of this species. A Bayesian assignment analysis demonstrated
that Brazilian wild forms of C. baccatum were genetically distant to all other accessions and made little to no contribution to the domesticated genepool. Moreover,
results of clustering analysis suggested that C. baccatum likely originated from present day Paraguay. Analysis of inter-specific relationships across selected Capsicum species supported independent lineages for the two crossability groups within Capsicum, the baccatum species-complex (including C. baccatum) and the annuum species-complex (including C. annuum, C. chinense and C. frutescens). However, the results did not support taxonomic distinction of C. baccatum var. umbilicatum from C. baccatum var. pendulum. The present study provides new insights into the domestication of C. baccatum. The results will be useful for identifying accessions for crop improvement and guiding the development of in situ and ex situ conservation programs. 相似文献
15.
Lufter Xhuveli 《Genetic Resources and Crop Evolution》2012,59(8):1605-1610
A special discussion, regarding the domestication of wild pomegranate (Punica granatum L.) in Albania, has first started in 1995. This discussion triggered a study that continued for the next several years. This research resulted in the identification of a wild pomegranate belt of about 300?km, along the Adriatic and Ionian coastline of the western part of Albania. Considering the results of this study regarding morphological, biological and biochemical assessments, toponymic and linguistic data, it is revealed that there are some indications that pomegranate could have been domesticated in Albania independently from other regions. 相似文献
16.
Ernesto Igartua Marian Moralejo Ana María Casas Lluís Torres José-Luis Molina-Cano 《Genetic Resources and Crop Evolution》2013,60(1):251-264
The discovery of Hordeum spontaneum C. Koch, a wild ancestor of cultivated barley, in Morocco in 1978 led to the proposal of a multicentric origin for this crop, as an alternative to the widely accepted theory of a single centre of domestication in the Fertile Crescent. Since this discovery, we have tested this hypothesis using the most advanced genetic techniques available at the time, from CM-proteins to RFLP and DNA-chloroplast markers. Nowadays, the availability of single nucleotide polymorphism (SNP) markers that are spread densely over the barley genome provides us with another powerful tool to give further support for the above. We have used 1,536 SNPs from the Barley Oligo Pool Assay 1 (BOPA1) of Illumina to characterize 107 wild and cultivated barley accessions from the Western Mediterranean, Fertile Crescent, Ethiopia, and Tibet. The results have confirmed that each location of the above-mentioned germplasm groups clusters separately. Analysis of molecular variance enabled us to focus on the chromosomal regions and loci that differentiated these groups of barley germplasm. Some of these regions contain vernalization and photoperiod response genes, some of the so-called domestication genes, as well as the most important quantitative trait locus for flowering time in the Mediterranean region. We have combined these results with other genetic evidence, and interpreted them in the framework of current theories on the onset of the Neolithic revolution in the Mediterranean region, to conclude that neither Ethiopia nor the Western Mediterranean can be ruled out as centres of barley domestication, together with the Fertile Crescent. 相似文献
17.
Gideon Ladizinsky 《Genetic Resources and Crop Evolution》1998,45(5):411-414
It is commonly agreed that cultivation of wild barley preceded the selection of the domesticated, non-brittle spike type. However, how common was wild barley cultivation before domestication and how many domesticated mutants gave rise to the barley crop could not be inferred from botanical and archaeological evidence. Some clues, nevertheless, can be obtained from the pattern of allozyme diversity in wild and cultivated barley obtained by Kahler and Allard (1981). Parallel variation, in terms of number of alleles per locus and frequency of the various alleles, was found in wild and domesticated barley. This similarity has been taken as an indication of multiple domestications and the frequency of the rarest alleles has been used to estimate that about 100 tough-rachis different mutants were necessary for the inclusion of the allozyme diversity of the wild barley in the domesticated crop. Assuming mutation rate of 10–6 in the locus governing tough rachis, the plant population required to generate these 100 mutants in one year would extend over about 200 hectares, or 10 hectares if the 100 mutants have been formed over a period of 20 years. The simplified calculations suggest that prior to domestication cultivation of wild barley was not a common practice. 相似文献
18.
19.
Ali Gharghani Zabihollah Zamani Alireza Talaie Nnadozie C. Oraguzie Reza Fatahi Hassan Hajnajari Claudia Wiedow Susan E. Gardiner 《Genetic Resources and Crop Evolution》2009,56(6):829-842
In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships
of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces,
selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the
wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of
Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information
on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA
extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25
alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic
data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics,
gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and
gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity
and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method
of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy
an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major
players in apples’ domestication and transfer from Central Asia to the western countries. 相似文献
20.
Effects of domestication on structural polysaccharides and dietary fiber in nopalitos (Opuntia spp.)
Cristian López-Palacios Cecilia Beatriz Pe?a-Valdivia J. Antonio Reyes-Agüero Adriana Inés Rodríguez-Hernández 《Genetic Resources and Crop Evolution》2012,59(6):1015-1026
Domestication is an evolutionary process that modifies morphological, physiological, chemical and genetic features of wild plants, and is a product of artificial selection. A gradient of domestication can be appreciated in species of the Opuntia genus. There are wild species like O. streptacantha, others semi-domesticated like O. hyptiacantha O. megacantha and O. albicarpa, or other like O. ficus-indica with the highest degree of domestication. At the same time, some structural polysaccharides have been associated with plant drought and freeze resistance. This study aimed at quantify five groups of structural polysaccharides in 14 variants of nopalitos (edible young cladodes of flat-stemmed spiny cacti consumed as vegetables) of Opuntia spp. in a domestication gradient. Given that extreme environment is less frequent under cultivation than in the wild, we hypothesized that structural polysaccharides in nopalitos are reduced throughout the domestication process. The experiment was conducted as a completely randomized design with a 5?×?14 two-factor factorial treatment structure, with four replications. Mucilages, pectins, hemicelluloses and cellulose were extracted and dietary fiber content was calculated. ANOVA of data was performed, pair wise comparisons of species and variants were conducted by Tukey test and principal components analysis was carried out. Mucilages were higher in O. ficus-indica (12% of total dry mass) and pectins, loosely and tightly bound hemicelluloses in O. streptacantha (2.5, 9 and 3%, respectively). All five species had similar content of cellulose (5.1% dry mass); but, O. streptacantha presented more dietary fiber. Higher pectins and both loosely and tightly bound hemicelluloses content in wild species can be related to genotype and the persistence of reaction to a wild environment. Mucilages which are one of the main characteristics of consumer preference and loosely bound hemicelluloses could have impact for selection during Opuntia domestication. 相似文献