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1.
A molecular genetic map of cassava (Manihot esculenta Crantz) 总被引:12,自引:0,他引:12
M. Fregene F. Angel R. Gomez F. Rodriguez P. Chavarriaga W. Roca J. Tohme M. Bonierbale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):431-441
A genetic linkage map of cassava has been constructed with 132 RFLPs, 30 RAPDs, 3 microsatellites, and 3 isoenzyme markers
segregating from the heterozygous female parent of an intraspecific cross. The F1 cross was made between ‘TMS 30572’ and ‘CM 2177-2’, elite cassava cultivars from Nigeria and Colombia, respectively. The
map consists of 20 linkage groups spanning 931.6 cM or an estimated 60% of the cassava genome. Average marker density is 1
per 7.9 cM. Since the mapping population is an F1 cross between heterozygous parents, with unique alleles segregating from either parent, a second map was constructed from
the segregation of 107 RFLPs, 50 RAPDs, 1 microsatellite, and 1 isoenzyme marker from the male parent. Comparison of intervals
in the male-and female-derived maps, bounded by markers heterozygous in both parents, revealed significantly less meiotic
recombination in the gametes of the female than in the male parent. Six pairs of duplicated loci were detected by low-copy
genomic and cDNA sequences used as probes. Efforts are underway to saturate the cassava map with additional markers, to join
the male- and female-derived maps, and to elucidate genome organization in cassava.
Received: 5 July 1996/Accepted: 22 November 1996 相似文献
2.
For genetic analysis and linkage mapping of bay scallop (Argopecten irradians), a set of 120 novel simple sequence repeat markers were developed from microsatellite-enriched libraries and expressed sequence
tags. An inter-subspecies hybrid bay scallop family (CC5) of 46 progeny was analyzed as the reference population to confirm
polymorphism and test the segregation patterns of these loci. A total of 104 microsatellite markers were polymorphic in the
reference family, among which 36 in female, 28 in male, and 40 in both parents, respectively. Linkage analysis allowed mapping
these markers to 15 linkage groups, which is close to the haploid chromosome number of bay scallop (n = 16). Analysis of the 40 markers segregating in both parents showed a higher recombination rate in the female parent, with
the average of female-to-male recombination ratio of 1.09:1 between linked pairs of markers. When null alleles were considered,
there were 17 loci showing segregation distortion at the 5% significance level using the chi-square test. The microsatellite
markers developed in this study provide a useful resource for future linkage mapping and quantitative loci analysis in A. irradians. 相似文献
3.
Maureen P. Martin Anita Harding Robert Chadwick Mel Kronick Michael Cullen Ling Lin Emmanuel Mignot M. Carrington 《Immunogenetics》1997,47(2):131-138
The human genome contains a large number of interspersed microsatellite repeats which exhibit a high degree of polymorphism
and are inherited in a Mendelian fashion, making them extremely useful genetic markers. Several microsatellites have been
described in the HLA region, but allele nomenclature, a set of broadly distributed controls, and typing methods have not been standardized, which
has resulted in discrepant microsatellite data between laboratories. In this report we present a detailed protocol for genotyping
microsatellites using a semi-automated fluorescence-based method. Twelve microsatellites within or near the major histocompatibility
complex (MHC) were typed in the 10th International Histocompatibility Workshop homozygous typing cell lines (HTCs) and alleles
were designated based on size. All loci were sequenced in two HTCs providing some information on the level of complexity of
the repeat sequence. A comparison of allele size obtained by genotyping versus that obtained by direct sequencing showed minor
discrepancies in some cases, but these were not unexpected given the technical differences in the methodologies. Fluorescence-based
typing of microsatellites in the MHC described herein is highly efficient, accurate, and reproducible, and will allow comparison
of results between laboratories.
Received: 10 May 1997 / Revised: 1 August 1997 相似文献
4.
Sethy NK Shokeen B Edwards KJ Bhatia S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(8):1416-1428
Paucity of polymorphic molecular markers in chickpea (Cicer arietinum L.) has been a major limitation in the improvement of this important legume. Hence, in an attempt to develop sequence-tagged microsatellite sites (STMS) markers from chickpea, a microsatellite enriched library from the C. arietinum cv. Pusa362 nuclear genome was constructed for the identification of (CA/GT)
n
and (CT/GA)
n
microsatellite motifs. A total of 92 new microsatellites were identified, of which 74 functional STMS primer pairs were developed. These markers were validated using 9 chickpea and one C. reticulatum accession. Of the STMS markers developed, 25 polymorphic markers were used to analyze the intraspecific genetic diversity within 36 geographically diverse chickpea accessions. The 25 primer pairs amplified single loci producing a minimum of 2 and maximum of 11 alleles. A total of 159 alleles were detected with an average of 6.4 alleles per locus. The observed and expected heterozygosity values averaged 0.32 (0.08–0.91) and 0.74 (0.23–0.89) respectively. The UPGMA based dendrogram was able to distinguish all the accessions except two accessions from Afghanistan establishing that microsatellites could successfully detect intraspecific genetic diversity in chickpea. Further, cloning and sequencing of size variant alleles at two microsatellite loci revealed that the variable numbers of AG repeats in different alleles were the major source of polymorphism. Point mutations were found to occur both within and immediately upstream of the long tracts of perfect repeats, thereby bringing about a conversion of perfect motifs into imperfect or compound motifs. Such events possibly occurred in order to limit the expansion of microsatellites and also lead to the birth of new microsatellites. The microsatellite markers developed in this study will be useful for genetic diversity analysis, linkage map construction as well as for depicting intraspecific microsatellite evolution. 相似文献
5.
M. I. Buteler R. L. Jarret D. R. LaBonte 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):123-132
The objectives of the present study were to evaluate the inheritance and nucleotide sequence profiles of microsatellite genetic
markers in hexaploid sweetpotato [Ipomoea batatas (L.) Lam.] and its putative tetraploid and diploid ancestors, and to test possible microsatellite mutation mechanisms in
polyploids by direct sequencing of alleles. Sixty three microsatellite loci were isolated from genomic libraries of I. batatas and sequenced. PCR primers were designed and used to characterize microsatellite loci in two hexaploid I. batatas populations, a tetraploid Ipomoea trifida population, and a diploid I. trifida population. Nine out of the sixty three primer pairs tested yielded a clearly discernible, heritable banding pattern; five
showed Mendelian segregation. All other primer pairs produced either smeared banding patterns, which could not be scored,
or no bands at all in I. batatas. All of the primers which produced discernible banding patterns from I. batatas also amplified products of similar size in tetraploid and diploid I. trifida accessions. The sequence analysis of several alleles in the three species showed differences due to mutations in the repeat
regions consistent with small differences in the repeat number. However, in some cases insertions/deletions and base substitutions
in the microsatellite flanking regions were responsible for polymorphisms in both polyploid and diploid species. These results
provide strong empirical evidence that complex genetic mechanisms are responsible for SSR allelic variation in Ipomoea. Four I. batatas microsatellite loci showed polysomic segregation fitting tetraploid segregation ratios. To our knowledge this is the first
report of segregation ratios for microsatellites markers in polyploids.
Received: 4 January 1999 / Accepted: 4 January 1999 相似文献
6.
Evaluation of allelic diversity at chloroplast microsatellite loci among common wheat and its ancestral species 总被引:14,自引:0,他引:14
T. Ishii N. Mori Y. Ogihara 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(6-7):896-904
Twenty four chloroplast microsatellite loci having more than ten mononucleotide repeats were identified from the entire chloroplast
DNA sequence of common wheat, Triticum aestivum cv Chinese Spring. For each microsatellite, a pair of primers were designed to produce specific PCR products in the range
of 100– 200 bp. The allelic diversity at the microsatellite loci was evaluated using 43 accessions from 11 Triticum and Aegilops species involved in wheat polyploid evolution. Polymorphic banding patterns were obtained at 21 out of 24 chloroplast microsatellite
loci. The three monomorphic microsatellites were found to be located in coding regions. For the polymorphic microsatellites,
the number of alleles per microsatellite ranged from 2 to 7 with an average of 4.33, and the diversity values (H) ranged from
0.05 to 0.72 with an average of 0.47. Significant correlations (P<0.01) were observed between the number of repeats and the number of alleles, and between the number of repeats and diversity
value, respectively. The genetic diversity explained by chloroplast microsatellites and nuclear RFLP markers were compared
using 22 tetraploid accessions. Although the number of alleles for nuclear RFLP markers was found to be higher than that for
chloroplast microsatellites, similar diversity values were observed for both types of markers. Among common wheat and its
ancestral species, the percentages of common chloroplast microsatellite alleles were calculated to examine their phylogenetic
relationships. As a result, Timopheevi wheat species were clearly distinguished from other species, and Emmer and common wheat
species were divided into two main groups, each consisting of a series of wild and cultivated species from tetraploid to hexaploid.
This indicates that the two types of chloroplast genomes of common wheat might have independently originated from the corresponding
types of wild and cultivated Emmer wheat species.
Received: 6 October 2000 / Accepted: 13 March 2001 相似文献
7.
Half-smooth tongue sole (Cynoglossus semilaevis) is a commercially important marine fish species in China. A set of type I microsatellite markers were identified through
bioinformatic mining of the GenBank database. Thirteen of these markers showed polymorphisms through genotyping a sample of
30 individuals. A total of 47 alleles were detected, with an average of 3.6 alleles per locus. The number of alleles, observed
and expected heterozygosity per locus ranged from two to five, from 0.14 to 0.93 and from 0.27 to 0.77, respectively. Three
loci significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction (P < 0.0038) and no significant linkage disequilibrum between pairs of loci was found. The markers identified in this study
will contribute to construction of genetic linkage maps and mapping of quantitative trait loci (QTL) of C. semilaevis. 相似文献
8.
Chromosomal regions associated with marker segregation distortion in rice were compared based on six molecular linkage maps.
Mapping populations were derived from one interspecific backcross and five intersubspecific (indica / japonica) crosses, including two F2 populations, two doubled haploid (DH) populations, and one recombinant inbred (RI) population. Mapping data for each population
consisted of 129–629 markers. Segregation distortion was determined based on chi-square analysis (P < 0.01) and was observed at 6.8–31.8% of the mapped marker loci. Marker loci associated with skewed allele frequencies were
distributed on all 12 chromosomes. Distortion in eight chromosomal regions bracketed previously identified gametophyte (ga) or sterility genes (S). Distortion in three other chromosomal regions was found only in DH populations, where japonica alleles were over-represented, suggesting that loci in these regions may be associated with preferential regeneration of
japonica genotypes during anther culture. Three additional clusters of skewed markers were observed in more than one population in
regions where no gametophytic or sterility loci have previously been reported. A total of 17 segregation distortion loci may
be postulated based on this study and their locations in the rice genome were estimated.
Received: 31 May 1996 / Accepted: 30 September 1996 相似文献
9.
Nonamplifying alleles at microsatellite loci: a caution for parentage and population studies 总被引:33,自引:0,他引:33
While genotyping wild red deer (Cervus elaphus) at microsatellite loci for paternity assignment, we found three loci (MAP65, BOVIRBP and CelJP23) with segregating nonamplifying alleles. Nonamplifying alleles were detected through mismatches between known mother-offspring pairs and by significant deviations from Hardy-Weinberg equilibria. In a wide range of molecular ecology applications, and especially in parentage assignment, the possible existence of undetectable alleles must be taken into account; this may be particularly important for microsatellite data. 相似文献
10.
P. Rallo G. Dorado A. Martín 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(5-6):984-989
We report the development of microsatellites or simple sequence repeats (SSRs) in the olive tree (Olea europaea L.). Forty three positive clones obtained by the screening of a GA-enriched genomic library were sequenced and primers were
designed for 13 microsatellite loci. Five primer pairs amplified polymorphic products of the expected size range. SSR polymorphism
was explored in a set of 46 olive cultivars. A total of 26 alleles were detected for the five loci. Heterozygosity ranged
from 0.46 to 0.71. Ninety one per cent of the cultivars had unique multilocus genotypes. Microsatellite segregation was studied
in a complex population from a cross between the commercial cultivars ’Leccino’ and ’Dolce Agogia’.
Received: 3 February 2000 / Accepted: 21 March 2000 相似文献
11.
Abundance, polymorphism and genetic mapping of microsatellites in rice 总被引:71,自引:0,他引:71
Dinucleotide microsatellites have been characterized and used as genetic markers in rice. Screening of a rice genomic library with poly(dG-dA)·(dC-dT) and poly(dG-dT)·(dC-dA) probes indicated that (GA)n repeats occurred, on average, once every 225 kb and (GT)n repeats once every 480 kb. DNA sequencing of ten randomly selected microsatellites indicated that the numbers of repeats ranged from 12 to 34 and that the patterns of microsatellites in rice were similar to those of humans and other mammals. Primers to these microsatellite loci as well as to four published microsatellite-containing sequences have been designed and degrees of polymorphism has been examined with 20 rice accessions. Multiple alleles, ranging from 5 to 11, have been observed at all the microsatellite loci in 20 rice accessions. Alleles specific to two cultivated subspecies, indica and japonica, were found in some microsatellite loci. Heterozygosity values of all the microsatellite markers were significantly higher than those of RFLP markers, based upon a parallel comparison. Ten microsatellite loci have been genetically mapped to four rice chromosomes. The genomic distribution of microsatellites appears to be random in rice. 相似文献
12.
M. M. Messmer M. Keller S. Zanetti B. Keller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(6-7):1163-1170
We constructed a genetic map of a cross between the Swiss winter wheat (Triticum aestivum L.) variety Forno and the Swiss winter spelt (Triticum spelta L.) variety Oberkulmer. For the linkage analysis,176 polymorphic RFLP probes and nine microsatellites were tested on 204
F5 recombinant inbred lines (RILs) of Forno×Oberkulmer revealing 242 segregating marker loci. Thirty five percent of these loci
showed significant (P>0.05) deviation from a 1 : 1 segregation, and the percentage of Forno alleles ranged from 21% to 83% for individual marker
loci. Linkage analysis was performed with the program MAPMAKER using the Haldane mapping function. Using a LOD threshold of
10, we obtained 37 linkage groups. After finding the best order of marker loci within linkage groups by multi-point analysis
we assembled the linkage groups into 23 larger units by lowering the LOD threshold. All except one of the 23 new linkage groups
could be assigned to physical chromosomes or chromosome arms according to hybridisation patterns of nulli-tetrasomic lines
of Chinese Spring and published wheat maps. This resulted in a genetic map comprising 230 marker loci and spanning 2469 cM.
Since the analysed population is segregating for a wide range of agronomically important traits, this genetic map is an ideal
basis for the identification of quantitative trait loci (QTLs) for these traits.
Received: 3 August 1998 / Accepted: 28 November 1998 相似文献
13.
Udupa SM Robertson LD Weigand F Baum M Kahl G 《Molecular & general genetics : MGG》1999,261(2):354-363
A set of 12 randomly selected (TAA)n microsatellite loci of the cultivated chickpea (Cicer arietinum L.) were screened in a worldwide sample comprising 72 landraces, four improved cultivars and two wild species of the primary
gene pool (C. reticulatum and C. echinosperum) to determine the level and pattern of polymorphism in these populations. A single fragment was amplified from all the accessions
with each of 12 sequence-tagged microsatellite site markers, except for one locus where no fragment was obtained from either
of the two wild species. There was a high degree of intraspecific polymorphism at these microsatellite loci, although isozymes,
conventional RFLPs and RAPDs show very little or no polymorphism. Overall, the repeat number at a locus (excluding null alleles)
ranged from 7 to 42. The average number of alleles per locus was 14.1 and the average genetic diversity was 0.86. Based on
the estimates obtained, 11 out of the 12 frequency distributions of alleles at the loci tested can be considered to be non-normal.
A significant positive correlation between the average number of repeats (size of the locus) and the amount of variation was
observed, indicating that replication slippage may be the molecular mechanism involved in generation of variability at the
loci. A comparison between the infinite allele and stepwise mutation models revealed that for 11 out of the 12 loci the number
of alleles observed fell in between the values predicted by the two models. Phylogenetic analysis of microsatellite polymorphism
in C. arietinum showed no relationship between accession and geographic origin, which is compatible with the recent expansion of this crop
throughout the world.
Received: 18 September 1998 / Accepted: 2 December 1998 相似文献
14.
A genetic linkage map of Quercus robur L. (pedunculate oak) based on RAPD, SCAR, microsatellite, minisatellite, isozyme and 5S rDNA markers 总被引:5,自引:0,他引:5
T. Barreneche C. Bodenes C. Lexer J.-F. Trontin S. Fluch R. Streiff C. Plomion G. Roussel H. Steinkellner K. Burg J.-M. Favre J. Glössl A. Kremer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(7):1090-1103
A genetic map of Pedunculate oak (Quercus robur) was constructed based on one 5S rDNA, 271 RAPD, ten SCAR, 18 microsatellite, one minisatellite, and six isozyme markers.
A total of 94 individuals from a full-sib family was genotyped. Two maps, including 307 markers, were constructed according
to the “two-way pseudo-testcross” mapping strategy. Testcross markers segregating in the 1 : 1 ratio were first used to establish
separate maternal (893.2 cM, 12 linkage groups) and paternal (921.7 cM, 12 linkage groups) maps. Both maps provided 85–90%
genome coverage. Homologies between the male and female linkage groups were then identified based on 74 intercross markers
segregating in the 3 : 1, 1 : 2 : 1 and 1 : 1 : 1 : 1 ratios (RAPDs, SCARs, SSRs, 5S rDNA and isozymes) in the hybrid progeny.
In each map, approximately 18% of the studied markers showed segregation distortion. More than 60% of the skewed markers were
due to an excess of heterozygote genotypes. This map will be used for: (1) studying the molecular organisation of genomic
regions involved in inter- and intraspecific differentiation in oaks and (2) identification of QTLs for adaptive traits.
Received: 30 January 1998 / Accepted: 12 May 1998 相似文献
15.
Use of microsatellites to evaluate genetic diversity and species relationships in the genus Lycopersicon 总被引:1,自引:0,他引:1
A. E. Alvarez C.C.M. van de Wiel M.J.M. Smulders B. Vosman 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(8):1283-1292
In order to determine how informative a set of microsatellites from tomato is across the genus Lycopersicon, 17 microsatellite loci, derived from regions in and around genes, were tested on 31 accessions comprising the nine species
of the genus. The microsatellite polymorphisms were used to estimate the distribution of diversity throughout the genus and
to evaluate the efficacy of microsatellites for establishing species relationships in comparison with existing phylogeny reconstructions.
Gene diversity and genetic distances were calculated. A high level of polymorphism was found, as well as a large number of
alleles unique for species. The level of polymorphism detected with the microsatellite loci within and among species was highly
correlated with the respective mating systems, cross-pollinating species having a significantly higher gene diversity compared
to self-pollinating species. In general, microsatellite-based trees were consistent with a published RFLP-based dendrogram
as well as with a published classification based on morphology and the mating system. A tree constructed with low-polymorphic
loci (gene diversity <0.245) was shown to represent a more-reliable topology than a tree constructed with more-highly polymorphic
loci.
Received: 19 February 2001 / Accepted: 26 March 2001 相似文献
16.
Development, inheritance and cross-species amplification of microsatellite markers from Acacia mangium 总被引:3,自引:0,他引:3
P. A. Butcher S. Decroocq Y. Gray G. F. Moran 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(8):1282-1290
Microsatellite markers were developed in Acacia mangium Willd. to provide highly variable co-dominant markers for linkage mapping and studies of the breeding system. After an enrichment
procedure 40% of colonies contained microsatellites in contrast with less than 1% from a non-enriched library. The majority
of microsatellite sequences were AC repeats. Co-dominant segregation of alleles in two full-sib crosses of A. mangium was demonstrated at 33 microsatellite loci. The markers were highly variable relative to restriction fragment lengths polymorphisms
(RFLPs). In the two pedigrees 53% of microsatellite loci were fully informative compared with 15% of RFLPs. Based on alleles
detected among four parental genotypes, the microsatellites consisting of dinucleotide repeats were more polymorphic than
those with tri- and tetra-nucleotide repeats. The microsatellite markers were not as transferable across species in the genus
Acacia as RFLPs. Two thirds of the primers developed in A. mangium (subgenus Phyllodineae, section Juliflorae) amplified DNA from other species within the same section but failed to amplify
in species from the subgenus Acacia. The availability of multiallelic, PCR-based, co-dominant microsatellite loci makes possible
efficient studies of gene flow and breeding systems in A. mangium, a species with low allozyme variation.
Received: 30 December 1999 / Accepted: 10 May 2000 相似文献
17.
During genotyping of 38 microsatellites for QTL (quantitative trait loci) mapping in three F2 swine populations, five mutant alleles were detected in a total of 66,436 parent-offspring transfers of microsatellite alleles, which gives an overall mutation rate of 7.52×10–5 per locus per generation. No significant (P<0.05) association between mutation rates and other factors (i.e., GC contents in the flanking regions, heterozygosity, and repeat number) was revealed. Detailed sequencing showed that four out of five mutant alleles were caused by insertions of one to five repeats, respectively. The other mutant allele was produced by either an insertion of three repeats or a change of 30 base pairs (a deletion of 16 CT repeats and an insertion of one CA repeat). An insertion of one base pair in the flanking region of a microsatellite was also detected. Together, these data indicate that expansions are more common than contractions among microsatellites and that the mutation processes are very complicated, do not fit with the strict stepwise mutation model and may vary from locus to locus. 相似文献
18.
M. Yaneshita S. Kaneko T. Sasakuma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(5):751-756
A RFLP linkage map of Zoysia spp. (2n=40), a warm-season turfgrass, was constructed by using the self-pollinated progenies obtained from an interspecific
hybrid. Out of 115 DNA clones tested, 100 (87.0%), including 55 genomic clones, 38 cDNA clones, and seven gene clones encoding
photosynthetic enzymes showed allelic-RFLP banding patterns among the parental accessions. We found that 26 probes detected
two or more loci segregating in the self-pollinated progenies independently. The RFLP linkage map of Zoysia spp. consists of 115 loci in 22 linkage groups ranging in size from 12.5 cM to 141.3 cM with a total map distance of 1506 cM.
Six RFLP loci (5.4%) showed significant segregation distortion (P<0.01). Two loci out of six were mapped to linkage group II, and another two loci were mapped to group VII. In the RFLP linkage
map of zoysiagrass, five pairs of linkage groups sharing a series of duplicated loci with approximately the same order were
identified. Therefore, we conclude that Zoysia spp. with 2n=40 should be considered as allotetraploids, which might have evolved from progenitors with a basic chromosome
number of ten (x=10).
Received: 20 March 1998 / Accepted: 17 September 1998 相似文献
19.
Genetic diversity and differentiation within and among nine G. morsitans morsitans populations from East and southern Africa was assessed by examining variation at seven microsatellite loci and a mitochondrial
locus, cytochrome oxidase (COI). Mean COI diversity within populations was 0.63 ± 0.33 and 0.81 taken over all populations. Diversities averaged over microsatellite
loci were high (mean number of alleles/locus ≥7.4; mean H
E ≥ 65%) in all populations. Diversities averaged across populations were greater in East Africa (mean number of alleles = 22 ± 2.6;
mean h
e = 0.773 ± 0.033) than in southern Africa (mean number of alleles = 18.7 ± 4.0; mean h
e = 0.713 ± 0.072). Differentiation among all populations was highly significant (R
ST = 0.25, F
ST = 0.132). Nei’s G
ij
statistics were 0.09 and 0.19 within regions for microsatellites and mitochondria, respectively; between regions, G
ij
was 0.14 for microsatellites and 0.23 for mitochondria. G
ST among populations was 0.23 for microsatellite loci and 0.40 for mitochondria. The F, G and R statistics indicate highly restricted gene flow among G. m. morsitans populations separated over geographic scales of 12–917 km. 相似文献
20.
Hedia Bourguiba Lamia Krichen Jean-Marc Audergon Bouchaib Khadari Neila Trifi-Farah 《Plant Molecular Biology Reporter》2010,28(4):578-587
The impact of mapped microsatellites on the study of genetic diversity of Tunisian apricot accessions was assessed. The genetic
variability of 47 traditional apricot cultivars originating from several areas in Tunisia was investigated with 32 polymorphic
microsatellite loci selected for their location throughout the eight linkage groups of Prunus genome. The higher polymorphism and greater transportability of these markers among Prunus species were proved by the expected heterozygosity (He = 0.56) and Shannon’s index of diversity (I = 1.05), indicating that Tunisian apricot germplasm maintained a substantial level of genetic diversity. According to their
geographical origin, the genetic differentiation among groups (north, center, and south; Fst = 0.04) was lower, while the
gene flow among groups was consequent (Nm = 4.79), attesting a narrow genetic background of apricot in the country. Both unweighted
pair-group method with arithmetic mean dendrogram, based on Nei’s genetic distances and factorial correspondence analysis,
separated northern cultivars from central and southern cultivars, revealing the same molecular basis of apricot material in
the Center and the South of Tunisia. These results revealed the efficiency of mapped markers for genetic variability measurements
compared to randomly ones, however, no advantage was observed considering the genetic relationships among studied accessions. 相似文献