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1.
T. Fahima G. L. Sun A. Beharav T. Krugman A. Beiles E. Nevo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):434-447
Genetic diversity in random amplified polymorphic DNAs (RAPDs) was studied in 110 genotypes of the tetraploid wild progenitor
of wheat, Triticum dicoccoides, from 11 populations sampled in Israel and Turkey. Our results show high level of diversity of RAPD markers in wild wheat
populations in Israel. The ten primers used in this study amplified 59 scorable RAPD loci of which 48 (81.4%) were polymorphic
and 11 monomorphic. RAPD analysis was found to be highly effective in distinguishing genotypes of T. dicoccoides originating from diverse ecogeographical sites in Israel and Turkey, with 95.5% of the 100 genotypes correctly classified
into sites of origin by discriminant analysis based on RAPD genotyping. However, interpopulation genetic distances showed
no association with geographic distance between the population sites of origin, negating a simple isolation by distance model.
Spatial autocorrelation of RAPD frequencies suggests that migration is not influential. Our present RAPD results are non-random
and in agreement with the previously obtained allozyme patterns, although the genetic diversity values obtained with RAPDs
are much higher than the allozyme values. Significant correlates of RAPD markers with various climatic and soil factors suggest
that, as in the case of allozymes, natural selection causes adaptive RAPD ecogeographical differentiation. The results obtained
suggest that RAPD markers are useful for the estimation of genetic diversity in wild material of T. dicoccoides and the identification of suitable parents for the development of mapping populations for the tagging of agronomically important
traits derived from T. dicoccoides.
Received: 13 July 1998 / Accepted: 13 August 1998 相似文献
2.
Genetic variance, coefficient of parentage, and genetic distance of six soybean populations 总被引:4,自引:0,他引:4
T. Helms G. Vallad P. McClean J. Orf 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):20-26
Plant breeders would like to predict which biparental populations will have the largest genetic variance. If the population
genetic variance could be predicted using coefficient of parentage or genetic distance estimates based on molecular marker
data, breeders could choose parents that produced segregating populations with a large genetic variance. Three biparental
soybean {Glycine max (L.) Merr.} populations were developed by crossing parents that were closely related, based on pedigree relationships. Three
additional biparental populations were developed by crossing parents that were assumed to be unrelated. The genetic variance
of each population was estimated for yield, lodging, physiological maturity, and plant height. Coefficient of parentage was
calculated for each pair of parents used to develop the segregating populations. Genetic distance was determined, based on
the number of random amplified polymorphic markers (RAPD) that were polymorphic for each pair of parents. Genetic distance
was not associated with the coefficient of parentage or the magnitude of the genetic variance. The genetic variance pooled
across the three closely related populations was smaller than the genetic variance pooled across the three populations derived
from crossing unrelated parents for all four traits that were evaluated.
Received: 24 April 1996 / Accepted: 17 May 1996 相似文献
3.
Francesco Frati Chris Simon Jack Sullivan David L. Swofford 《Journal of molecular evolution》1997,44(2):145-158
The sequence of the mitochondrial COII gene has been widely used to estimate phylogenetic relationships at different taxomonic
levels across insects. We investigated the molecular evolution of the COII gene and its usefulness for reconstructing phylogenetic
relationships within and among four collembolan families. The collembolan COII gene showed the lowest A + T content of all
insects so far examined, confirming that the well-known A + T bias in insect mitochondrial genes tends to increase from the
basal to apical orders. Fifty-seven percent of all nucleotide positions were variable and most of the third codon positions
appeared free to vary. Values of genetic distance between congeneric species and between families were remarkably high; in
some cases the latter were higher than divergence values between other orders of insects. The remarkably high divergence levels
observed here provide evidence that collembolan taxa are quite old; divergence levels among collembolan families equaled or
exceeded divergences among pterygote insect orders. Once the saturated third-codon positions (which violated stationarity
of base frequencies) were removed, the COII sequences contained phylogenetic information, but the extent of that information
was overestimated by parsimony methods relative to likelihood methods. In the phylogenetic analysis, consistent statistical
support was obtained for the monophyly of all four genera examined, but relationships among genera/families were not well
supported. Within the genus Orchesella, relationships were well resolved and agreed with allozyme data. Within the genus Isotomurus, although three pairs of populations were consistently identified, these appeared to have arisen in a burst of evolution from
an earlier ancestor. Isotomurus italicus always appeared as basal and I. palustris appeared to harbor a cryptic species, corroborating allozyme data.
Received: 12 January 1996 / Accepted: 10 August 1996 相似文献
4.
Genetic Evidence for Gonochoristic Reproduction in Gynogenetic Silver Crucian Carp (Carassius auratus gibelio Bloch) as Revealed by RAPD Assays 总被引:14,自引:0,他引:14
Sex evolution has been a debating focus in evolutionary genetics. In lower vertebrates of reptiles, amphibians, and fish,
a species or a bioform reproduces either sexually or asexually but never both. A few species were found to consist of all
females in fish. These all-female species can propagate by asexual reproduction modes, such as gynogenesis and hybridogenesis.
However, the coexistence of sexuality and asexuality in a single species was recently noted only in a cyprinid fish silver
crucian carp, Carassius auratus gibelio. This fish had been demonstrated to be capable of gynogenesis stimulated by sperm from other related species. Surprisingly,
natural populations of this fish consist of a minor but significant portion (approx. 20%) of males. As different clones with
specific phenotypic and genetic characteristics have been found, and RAPD markers specific to each clone have recently been
identified, this fish offers many advantages for analyzing whether or not genetic recombination occurs between different clones.
In this study, artificial propagation was performed in clone F and clone D. Ovulated eggs from clone F were divided into two
parts and respectively inseminated with sperm from a clone D male and from a red common carp (Cyprinus carpio) male. The control clone D individuals were selected from gynogenetic offspring of clone D activated by sperm of red common
carp. The phenotype and sex ratio in the experimental groups were also observed. Using RAPD molecular markers, which allow
for reliable discrimination and genetic analysis of different clones, we have revealed direct molecular evidence for gonochoristic
reproduction in the gynogenetic silver crucian carp and confirmed a previous hypothesis that the silver crucian carp might
reproduce both gynogenetically and gonochoristically. Therefore, we conclude that the silver crucian carp possesses two reproductive
modes, i.e., gynogenetic and gonochoristic reproduction. The response mechanism of two reproductive development modes may
be the first discovery in vertebrates. Additionally, we discuss the evolutionary implication between gynogenetic and gonochoristic
reproduction modes and the contribution of the minor proportion of males to genetic flexibility in the gynogenetic silver
crucian carp.
Received: 5 January 2000 / Accepted: 3 August 2000 相似文献
5.
Frédérique Viard Pierre Franck Marie-Pierre Dubois Arnaud Estoup Philippe Jarne 《Journal of molecular evolution》1998,47(1):42-51
Size homoplasy was analyzed at microsatellite loci by sequencing electromorphs, that is, variants of the same size (base
pairs). This study was conducted using five interrupted and/or compound loci in three invertebrate species, the honey bee
Apis mellifera, the bumble bee Bombus terrestris, and the freshwater snail Bulinus truncatus. The 15 electromorphs sequenced turned out to hide 31 alleles (i.e., variants identical in sequence). Variation in the amount
of size homoplasy was detected among electromorphs and loci. From one to seven alleles were detected per electromorph, and
one locus did not show any size homoplasy in both bee species. The amount of size homoplasy was related to the sequencing
effort, since the number of alleles was correlated with the number of copies of electromorphs sequenced, but also with the
molecular structure of the core sequence at each locus. Size homoplasy within populations was detected only three times, meaning
that size homoplasy was detected mostly among populations. We analyzed population structure, estimating F
st and a genetic distance, based on either electromorphs or alleles. Whereas little difference was found in A. mellifera, uncovering size homoplasy led to a more marked population structure in B. terrestris and B. truncatus. We also showed in A. mellifera that the detection of size homoplasy may alter phylogenetic reconstructions.
Received: 21 July 1997 / Accepted: 29 January 1998 相似文献
6.
Use of RAPD analyses to estimate population genetic parameters in the alfalfa leaf-cutting bee, Megachile rotundata. 总被引:1,自引:0,他引:1
RAPD analyses were performed on five geographically isolated populations of Megachile rotundata. We used haploid males of the alfalfa leaf-cutting bee, M. rotundata, to overcome the limitation of the dominance of RAPD markers in the determination of population genetic parameters. Sixteen primers gave rise to 130 polymorphic and 31 monomorphic bands. The unbiased estimators calculated in this study include within- and between-population heterozygosity, nucleotide divergence, and genetic distance. The genetic diversity (H = 0.32-0.35) was found to be about 10 times that of previous estimates (H = 0.033) based on allozyme data. Contrary to the data obtained at the protein level, our results suggest that Hymenoptera do not have a lower level of genetic variability at the DNA level compared with other insect species. Regardless of the different assumptions underlying the calculation of heterozygosity, divergence, and genetic distance, all five populations showed a parallel interrelationship for the three parameters. We conclude that RAPD markers are a convenient tool to estimate population genetic variation in haploid M. rotundata and that with an adequate sample size the technique is applicable to the evaluation of divergence in diploid populations. Key words : Megachile rotundata, RAPD, heterozygosity, genetic distance, nucleotide divergence. 相似文献
7.
Population structure of the banana weevil, an introduced pest in the Canary Islands, studied by RAPD analysis 总被引:1,自引:0,他引:1
Magaña C Beroiz B Hernández-Crespo P Montes de Oca M Carnero A Ortego F Castañera P 《Bulletin of entomological research》2007,97(6):585-590
The banana weevil (BW), Cosmopolites sordidus (Coleoptera: Curculionidae), is one of the most important insect pests of bananas and plantains. The mobility and the origin of BW infestations at the Canary Islands (Tenerife, La Gomera and La Palma) have been analysed using Random Amplified Polymorphic DNA (RAPD) as molecular markers. Populations from Costa Rica, Colombia, Uganda and Madeira were also included for comparison. One hundred and fifteen reproducible bands from eight primers were obtained. The level of polymorphism in the populations from the Canary Islands (40-62%) was in the range of those found in other populations. Nei's genetic distances, pair-wise fixation index (FST) values indicate that the closest populations are Tenerife populations among themselves (Nei's genetic distance=0.054-0.100; FST=0.091-0.157) and Costa Rica and Colombia populations (Nei's genetic distance=0.049; FST=0.113). Our results indicate the existence of BW local biotypes with limited gene flow and affected by genetic drift. These results are compatible with a unique event of colonization at Tenerife; whereas, the outbreaks in La Gomera and La Palma may come from independent introductions. The Madeira population is phylogenetically and geographically closer to the Canary Islands populations, suggesting that it is the most likely source of the insects introduced in the Canary Islands. 相似文献
8.
Genetic variation within and among populations of a wild rice Oryza granulata from China detected by RAPD and ISSR markers 总被引:37,自引:0,他引:37
W. Qian S. Ge D.-Y. Hong 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(2-3):440-449
Genetic variation within and between five populations of Oryza granulata from two regions of China was investigated using RAPD (random amplified polymorphic DNA) and ISSR (inter-simple sequence
repeat amplification) markers. Twenty RAPD primers used in this study amplified 199 reproducible bands with 61 (30.65%) polymorphic;
and 12 ISSR primers amplified 113 bands with 52 (46.02%) polymorphic. Both RAPD and ISSR analyses revealed a low level of
genetic diversity in wild populations of O. granulata. Furthermore, analysis of molecular variance (AMOVA) was used to apportion the variation within and between populations both
within and between regions. As the RAPD markers revealed, 73.85% of the total genetic diversity resided between the two regions,
whereas only 19.45% and 6.70% were present between populations within regions and within a population respectively. Similarly,
it was shown by ISSR markers that a great amount of variation (49.26%) occurred between the two regions, with only 38.07%
and 12.66% between populations within regions and within a population respectively. Both the results of a UPGMA cluster, based
on Jaccard coefficients, and pairwise distance analysis agree with that of the AMOVA partition. This is the first report of
the partitioning of genetic variability within and among populations of O. granulata at the DNA level, which is in general agreement with a recent study on the same species in China using allozyme analysis.
Our results also indicated that the percentage of polymorphic bands (PPB) detected by ISSR is higher than that detected by
RAPD. It seems that ISSR is superior to RAPD in terms of the polymorphism detected and the amplification reproducibility.
Received: 29 March 2000 / Accepted: 15 May 2000 相似文献
9.
Balciuniene J Syvänen AC McLeod HL Pettersson U Jazin EE 《Journal of molecular evolution》2001,52(2):157-163
Every genetic locus mingles the information about the evolutionary history of the human species with the history of its own
evolution. Therefore, to address the question of the origin of humans from a genetic point of view, evolutionary histories
from many genetic loci have to be gathered and compared. We have studied two genes residing on the X chromosome encoding monoamine
oxidases A and B (MAOA and MAOB). Both genes have been suggested to play a role in psychiatric and/or behavioral traits. To search for DNA variants of the
MAO genes, the sequences of exonic and flanking intronic regions of these two genes were determined in a group of Swedish males.
The sequence analysis revealed several novel polymorphisms in the MAO genes. Haplotypes containing high-frequency MAOA polymorphisms were constructed, and their frequencies were determined in additional samples from Caucasian, Asian, and African
populations. We found two common haplotypes with similar frequencies in Caucasian and Asian populations. However, only one
of them was also the most frequent haplotype in Africans, while the other haplotype was present in only one Kenyan male. This
profound change in haplotype frequencies from Africans to non-Africans supports a possible bottleneck during the dispersion
of modern humans from Africa.
Received: 19 April 2000 / Accepted: 9 October 2000 相似文献
10.
Grishin NV 《Journal of molecular evolution》1999,48(3):264-273
The reliable reconstruction of tree topology from a set of homologous sequences is one of the main goals in the study of
molecular evolution. If consistent estimators of distances from a multiple sequence alignment are known, the distance method
is attractive because the tree reconstruction is consistent. To obtain a distance estimate d, the observed proportion of differences p (p-distance) is usually ``corrected' for multiple and back substitutions by means of a functional relationship d=f(p). In this paper the conditions under which this correction of p-distances will not alter the selection of the tree topology are specified. When these conditions are not fulfilled the selection
of the tree topology may depend on the correction function applied. A novel method which includes estimates of distances not
only between sequence pairs, but between triplets, quadruplets, etc., is proposed to strengthen the proper selection of correction
function and tree topology. A ``super' tree that includes all tree topologies as special cases is introduced.
Received: 17 February 1998 / Accepted: 20 July 1998 相似文献
11.
Briscoe AD 《Journal of molecular evolution》2000,51(2):110-121
It has been hypothesized that the UV-, blue-, and green-sensitive visual pigments of insects were present in the common ancestor
of crustaceans and insects, whereas red-sensitive visual pigments evolved later as a result of convergent evolution. This
hypothesis is examined with respect to the placement of six opsins from the swallowtail butterfly Papilio glaucus (PglRh1–6) in relationship to 46 other insect, crustacean, and chelicerate opsin sequences. All basal relationships established
with maximum parsimony analysis except two are present in the distance and maximum likelihood analyses. In all analyses, the
six P. glaucus opsins fall into three well-supported clades, comprised, respectively, of ultraviolet (UV), blue, and long-wavelength (LW)
pigments, which appear to predate the radiation of the insects. Lepidopteran green- and red-sensitive visual pigments form
a monophyletic clade, which lends support to the hypothesis from comparative physiological studies that red-sensitive visual
pigments in insects have paralogous origins. Polymorphic amino acid sites (180, 197, 277, 285, 308), which are essential for
generating the spectral diversity among the vertebrate red- and green-sensitive pigments are notably invariant in the Papilio red- and green-sensitive pigments. Other major tuning sites must be sought to explain the spectral diversification among
these and other insect visual pigments.
Received: 6 December 1999 / Accepted: 3 April 2000 相似文献
12.
G. Gagne P. Roeckel-Drevet B. Grezes-Besset P. Shindrova P. Ivanov C. Grand-Ravel F. Vear D. Tourvieille de Labrouhe G. Charmet P. Nicolas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1216-1222
The parasitic plant Orobanche cumana Wallr. has become a limiting factor for sunflower crops in infested countries. Over the past few years the progression of
this parasitic plant, its introduction into new countries, and the development of new and more virulent races have all been
observed. Consequently, the survey and understanding of broomrape population evolution is now crucial for the establishment
of efficient breeding programmes. With this in prospect, the genetic variability of O. cumana populations from infested European countries, Bulgaria, Romania, Turkey and Spain, was studied using RAPD markers. Eight
populations with a total of 180 plants were analysed. Twenty three primers were used to obtain 133 reproducible bands which
led to a binary matrix. This matrix was subjected to various complementary analyses including pairwise distances computed
with the Nei and Li coefficient, AMOVA, Nei’s genetic diversity statistics, and an estimation of gene flow among populations
with the infinite-island formula. The results gave consistent conclusions whatever the method used for data treatment. We
show that this parasitic plant is probably self-pollinated, that there is little intra-population variability, and very little
gene exchange appears to occur between different geographic regions. Populations were well structured and organized into two
distinct groups (one group corresponding to the East European countries, Bulgaria, Romania and Turkey, and the other group
corresponding to Spanish populations) and could have a monophyletic origin. These results are discussed in relation to the
applied uses of RAPD markers in the determination of true O. cumana races instead of populations.
Received: 20 December 1997 / Accepted: 4 February 1998 相似文献
13.
Ceratapion basicorne is a prospective biological control agent of yellow starthistle (Centaurea solstitialis), which is an invasive alien weed in the USA. Although the weevil has a strong preference for yellow starthistle, it has been reported to develop sometimes on safflower in larval transfer and no-choice experiments. Although safflower was not attacked by this insect in previous field experiments, a release permit was denied because of concern for risk to safflower. Adult C. basicorne were released in a field experiment in which two varieties of safflower were grown in solid blocks on either side of a small number of yellow starthistle plants. Plants were dissected at the time of weevil pupation. Immature insects were reared to adult stage on artificial diet or were preserved in acetone to identify by molecular genetic analysis. C. basicorne infested 54% of the yellow starthistle plants and 0% of 1021 safflower plants. A different weevil, Ceratapion orientale, infested 1.5% of the safflower plants. These results corroborate two other published field studies in which C. basicorne was not reared from safflower. The combined results of nine experiments provide a point estimate that the probability of attack is less than 0.00059, with 99.9% confidence that it is less than 0.0045. The consistency of results from field experiments in three countries and the absence of any report of this insect being reared from safflower in the field in the weevil’s native range support the conclusion that this insect poses no significant risk to safflower. 相似文献
14.
Karen Miller Clare Lynch Joanne Martin Elisabeth Herniou Michael Tristem 《Journal of molecular evolution》1999,49(3):358-366
Gypsy LTR-retrotransposons have been identified in the genomes of many organisms, but only a small number of vertebrate examples
have been reported to date. Here we show that members of this family are likely to be widespread in many vertebrate classes
with the possible exceptions of mammals and birds. Phylogenetic analyses demonstrate that although there are several distinct
lineages of vertebrate gypsy LTR-retrotransposons, the majority clusters into one monophyletic clade. Groups of fungal, plant, and insect elements were
also observed, suggesting horizontal transfer between phyla may be infrequent. However, in contrast to this, there was little
evidence to support sister relationships between elements derived from vertebrate and insect hosts. In fact, the majority
of the vertebrate elements appeared to be most closely related to a group of gypsy LTR-retrotransposons present within fungi. This implies either that at least one horizontal transmission between these two
phyla has occurred previously or that a gypsy LTR-retrotransposon lineage has been lost from insect taxa.
Received: 22 December 1998 / Accepted: 6 April 1999 相似文献
15.
A method to measure genetic distance between allogamous populations of alfalfa (Medicago sativa) using RAPD molecular markers 总被引:2,自引:0,他引:2
M. Ghérardi B. Mangin B. Goffinet D. Bonnet T. Huguet 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(3-4):406-412
Alfalfa (Medicago sativa L.) is a forage legume of world-wide importance whose both allogamous and autotetraploid nature maximizes the genetic diversity
within natural and cultivated populations. This genetic diversity makes difficult the discrimination between two related populations.
We analyzed this genetic diversity by screening DNA from individual plants of eight cultivated and natural populations of
M. sativa and M. falcata using the RAPD method. A high level of genetic variation was found within and between populations. Using five primers, 64
intense bands were scored as present or absent across all populations. Most of the loci were revealed to be highly polymorphic
whereas very few population-specific polymorphisms were identified. From these observations, we adopted a method based on
the Roger’s genetic distance between populations using the observed frequency of bands to discriminate populations pairwise.
Except for one case, the between-population distances were all significantly different from zero. We have also determined
the minimal number of bands and individuals required to test for the significance of between-population distances.
Received: 7 July 1997 / Accepted: 28 October 1997 相似文献
16.
The boll weevil (Anthonomus grandis Boheman) is an insect pest of cotton that underwent a well-documented range expansion across the southeastern U.S. from Mexico
beginning about 110 years ago. Eleven microsatellite loci were surveyed to infer the magnitude and pattern of genetic differentiation
among boll weevil populations from 18 locations across eight U.S. states and northeast Mexico. Estimates of genetic diversity
(allelic diversity and heterozygosity) were greater in Southern than Northern populations, and were greater in the west than
the east among Northern populations. Boll weevil populations were genetically structured as a whole across the geographic
range sampled, with a global F
ST of 0.241. South-central populations exhibit classic isolation by distance, but evidence suggests that populations within
the Eastern and Western regions have not yet reached genetic equilibrium. Gene flow appears to be relatively high among populations
within the Eastern region. Population assignment data and estimates of gene flow indicate that migration between locations
separated by < 300 km is frequent. The database of microsatellite genotypes generated in this study now makes it possible,
through population assignment techniques, to identify the most likely geographic source of a boll weevil reintroduced to an
eradication zone, which will help action agencies decide the most appropriate mitigation response.
Kyung Seok Kim - Formerly: USDA-ARS, Areawide Pest Management Research Unit, 2771 F & B Rd., College Station,TX 77845, USA. 相似文献
17.
B. Román D. Rubiales A. M. Torres J. I. Cubero Z. Satovic 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(6-7):1108-1114
The pattern of genetic variation within and among natural populations of broomrape (Orobanche crenata Forsk.) from southern Spain was analysed by RAPD markers. Hierarchical analysis of phenotypic diversity using AMOVA was performed
to analyse the partitioning of the variation among populations and among individuals. Although most of the genetic diversity
was attributable to differences among individuals within a population (94.29%), significant φst values among populations suggested the existence of phenotypic differentiation. Moreover, corresponding HOMOVA analysis revealed
that molecular variances were significantly heterogeneous among populations although no clear grouping pattern could be established.
These results are to be expected considering the predominant outcrossing behaviour of O. crenata.
Received: 10 January 2001 / Accepted: 12 February 2001 相似文献
18.
Mapping of the Rf-3 nuclear fertility-restoring gene for WA cytoplasmic male sterility in rice using RAPD and RFLP markers 总被引:24,自引:0,他引:24
G. Zhang Y. Lu T. S. Bharaj S. S. Virmani N. Huang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):27-33
The cytoplasmic male sterility (CMS) of wild-abortive (WA) cytoplasm has been widely used for breeding hybrid rice. Two restorer
genes for the CMS have been found by traditional genetic analysis. To tag the restorer genes we used a set of near-isogenic
lines (NILs) of Zhenshan 97 carrying different genotypes for fertility restoration from IR24, to perform RAPD analysis. From
the survey of 720 random primers, six RAPD markers were identified to be associated with Rf-3. Three of these OPK05-800, OPU10-1100 and OPW01-350, were mapped on chromosome 1. Two populations from the crosses between Zhenshan 97 A and a near-isogenic restorer line ZSR21 and between Zhenshan 97 A and
IR24 were used for mapping Rf-3. The three RAPD markers and three RFLP markers, RG532, RG140 and RG458, were found to be closely linked to Rf-3 in the two populations. The same location of Rf-3 was also found in a population from the cross of IR58025 A//IR36/IR58025 B. At the RG532 locus, different alleles were found between two CMS
lines, Zhenshan 97 A and IR58025 A, and between two restorer lines, IR24 and IR36. The use of these molecular markers closely
linked to Rf-3 in facilitating the development of hybrid rice is discussed.
Received: 3 January 1996 / Accepted: 17 May 1996 相似文献
19.
Microsatellite polymorphism in natural populations of wild emmer wheat,Triticum dicoccoides,in Israel 总被引:5,自引:0,他引:5
Fahima T Röder MS Wendehake K Kirzhner VM Nevo E 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(1):17-29
Diversity in 20 microsatellite loci of wild emmer wheat, Triticum dicoccoides, was examined in 15 populations (135 genotypes) representing a wide range of ecological conditions of soil, temperature, and
water availability, in Israel and Turkey. An extensive amount of diversity at microsatellite loci was observed despite the
predominantly selfing nature of this plant species. The 20 Gatersleben wheat microsatellites (GWM), representing 13 chromosomes
of genomes A and B of wheat, revealed a total of 364 alleles, with an average of 18 alleles per GWM marker (range: 5–26).
The proportion of polymorphic loci per population averaged 0.90 (range: 0.45– 1.00); genic diversity, He, averaged 0.50 (range 0.094– 0.736); and Shannon’s information index averaged 0.84 (range 0.166–1.307). The coefficients
of genetic distance between populations were high and averaged D=1.862 (range 0.876–3.320), an indication of sharp genetic divergence over short distances. Interpopulation genetic distances
showed no association with geographic distance between the population sites of origin, which ruled out a simple isolation
by distance model. Genetic dissimilarity values between genotypes were used to produce a dendrogram of the relationships among
wild wheat populations by the unweighted pair-group method with arithmetic averages (UPGMA). The results showed that all the
wild emmer wheat populations could be distinguished. Microsatellite analysis was found to be highly effective in distinguishing
genotypes of T. dicoccoides, originating from diverse ecogeographical sites in Israel and Turkey, with 88% of the 135 genotypes correctly classified into
sites of origin by discriminant analysis. Our present microsatellite results are non-random and in agreement with the previously
obtained allozyme and RAPD patterns, although the genetic-diversity values obtained with microsatellites are much higher.
Significant correlates of microsatellite markers with various climatic and soil factors suggest that, as in allozymes and
RAPDs, natural selection causes adaptive microsatellite ecogeographical differentiation, not only in coding, but most importantly
in non-coding genomic regions. Hence, the concept of ”junk DNA” needs to be replaced by at least partly regulatory DNA. The
obtained results suggest that microsatellite markers are useful for the estimation of genetic diversity in natural populations
of T. dicoccoides and for the tagging of agronomically important traits derived from wild emmer wheat.
Received: 27 February 2001 / Accepted: 22 March 2001 相似文献
20.
Takuma Watanobe Naotaka Ishiguro Naohiko Okumura Masuo Nakano Akira Matsui Hitomi Hongo Hiroshi Ushiro 《Journal of molecular evolution》2001,52(3):281-289
The Kabukai A site (5 to 8C A.D.) of the Okhotsk cultural area is on Rebun Island, a small island near the coast, north–northwest
of Hokkaido, Japan. Specimens of Sus scrofa, called the Sakhalin pig, were discovered in five cultural layers at the Kabukai A site. Ancient DNA was extracted from the
remains of 42 Sakhalin pig bones. Thirty-nine nucleotide sequences of the 574-bp mitochondrial DNA control region, estimated
to have originated from at least 21 individuals, were amplified and analyzed phylogenetically. Nine distinct haplotypes (A1,
A2, A3, B1, B2, C1, C2, D1, and D2) from this site were classified into four haplotype groups (A, B, C, and D) by parsimonious
network analysis. Phylogenetic analysis of 9 ancient and 55 modern haplotypes indicated that the population of Sakhalin pigs
at the Kabukai A site belonged to two distinct clusters; haplotype groups A and B formed a cluster comprised only of themselves,
and haplotype groups C and D belonged to the cluster of one of the two genetic groups of Japanese wild boars uniquely distributed
in the western part of Japan, including one northeast Mongolian wild boar. Analysis of the haplotype distribution among three
archaeological sites and their historical transitions among the five layers reflecting the cultural periods at the Kabukai
A site suggests that the Sakhalin pig populations were introduced from Sakhalin island and the Amur River basin in the northeastern
Eurasian continent together with some cultural influences.
Received: 18 April 2000 / Accepted: 24 November 2000 相似文献