共查询到20条相似文献,搜索用时 31 毫秒
1.
Doligez A Adam-Blondon AF Cipriani G Di Gaspero G Laucou V Merdinoglu D Meredith CP Riaz S Roux C This P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(3):369-382
A grapevine (mainly Vitis vinifera L., 2n = 38) composite genetic map was constructed with CarthaGene using segregation data from five full-sib populations of 46, 95, 114, 139 and 153 individuals, to determine the relative position of a large set of molecular markers. This consensus map comprised 515 loci (502 SSRs and 13 other type PCR-based markers), amplified using 439 primer pairs (426 SSRs and 13 others) with 50.1% common markers shared by at least two crosses. Out of all loci, 257, 85, 74, 69 and 30 were mapped in 1, 2, 3, 4 and 5 individual mapping populations, respectively. Marker order was generally well conserved between maps of individual populations, with only a few significant differences in the recombination rate of marker pairs between two or more populations. The total length of the integrated map was 1,647 cM Kosambi covering 19 linkage groups, with a mean distance between neighbour loci of 3.3 cM. A framework-integrated map was also built, with marker order supported by a LOD of 2.0. It included 257 loci spanning 1,485 cM Kosambi with a mean inter-locus distance of 6.2 cM over 19 linkage groups. These integrated maps are the most comprehensive SSR-based maps available so far in grapevine and will serve either for choosing markers evenly scattered over the whole genome or for selecting markers that cover particular regions of interest. The framework map is also a useful starting point for the integration of the V. vinifera physical and genetic maps.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
2.
Di Gaspero G Cipriani G Adam-Blondon AF Testolin R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(7):1249-1263
Genetic maps functionally oriented towards disease resistance have been constructed in grapevine by analysing with a simultaneous
maximum-likelihood estimation of linkage 502 markers including microsatellites and resistance gene analogs (RGAs). Mapping
material consisted of two pseudo-testcrosses, ‘Chardonnay’ × ‘Bianca’ and ‘Cabernet Sauvignon’ × ‘20/3’ where the seed parents
were Vitis vinifera genotypes and the male parents were Vitis hybrids carrying resistance to mildew diseases. Individual maps included 320–364 markers each. The simultaneous use of two
mapping crosses made with two pairs of distantly related parents allowed mapping as much as 91% of the markers tested. The
integrated map included 420 Simple Sequence Repeat (SSR) markers that identified 536 SSR loci and 82 RGA markers that identified
173 RGA loci. This map consisted of 19 linkage groups (LGs) corresponding to the grape haploid chromosome number, had a total
length of 1,676 cM and a mean distance between adjacent loci of 3.6 cM. Single-locus SSR markers were randomly distributed
over the map (CD = 1.12). RGA markers were found in 18 of the 19 LGs but most of them (83%) were clustered on seven LGs, namely
groups 3, 7, 9, 12, 13, 18 and 19. Several RGA clusters mapped to chromosomal regions where phenotypic traits of resistance
to fungal diseases such as downy mildew and powdery mildew, bacterial diseases such as Pierce’s disease, and pests such as
dagger and root-knot nematode, were previously mapped in different segregating populations. The high number of RGA markers
integrated into this new map will help find markers linked to genetic determinants of different pest and disease resistances
in grape.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
An integrated AFLP and RFLP Brassica oleracea linkage map from two morphologically distinct doubled-haploid mapping populations 总被引:4,自引:4,他引:0
R. L. Sebastian E. C. Howell G. J. King D. F. Marshall M. J. Kearsey 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(1):75-81
Genetical maps of molecular markers in two very different F1-derived doubled-haploid populations of Brassica oleracea are compared and the first integrated map described. The F1 crosses were: Chinese kale×calabrese (var. alboglabra×var. italica) and cauliflower×Brussels sprout (var. botrytis×var. gemmifera). Integration of the two component maps using Joinmap v.2.0 was based on 105 common loci including RFLPs, AFLPs and microsatellites.
This provided an effective method of producing a high-density consensus linkage map of the B. oleracea genome. Based on 547 markers mapping to nine linkage groups, the integrated map covers a total map length of 893 cM, with
an average locus interval of 2.6 cM. Comparisons back to the component linkage maps revealed similar sequences of common markers,
although significant differences in recombination frequency were observed between some pairs of homologous markers. Map integration
resulted in an increased locus density and effective population size, providing a stronger framework for subsequent physical
mapping and for precision mapping of QTLs using substitution lines.
Received: 5 February 1999 / Accepted: 16 June 1999 相似文献
4.
Marcel TC Varshney RK Barbieri M Jafary H de Kock MJ Graner A Niks RE 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(3):487-500
A consensus map of barley was constructed based on three reference doubled haploid (DH) populations and three recombinant
inbred line (RIL) populations. Several sets of microsatellites were used as bridge markers in the integration of those populations
previously genotyped with RFLP or with AFLP markers. Another set of 61 genic microsatellites was mapped for the first time
using a newly developed fluorescent labelling strategy, referred to as A/T labelling. The final map contains 3,258 markers
spanning 1,081 centiMorgans (cM) with an average distance between two adjacent loci of 0.33 cM. This is the highest density
of markers reported for a barley genetic map to date. The consensus map was divided into 210 BINs of about 5 cM each in which
were placed 19 quantitative trait loci (QTL) contributing to the partial resistance to barley leaf rust (Puccinia hordei Otth) in five of the integrated populations. Each parental barley combination segregated for different sets of QTLs, with
only few QTLs shared by any pair of cultivars. Defence gene homologues (DGH) were identified by tBlastx homology to known
genes involved in the defence of plants against microbial pathogens. Sixty-three DGHs were located into the 210 BINs in order
to identify candidate genes responsible for the QTL effects. Eight BINs were co-occupied by a QTL and DGH(s). The positional
candidates identified are receptor-like kinase, WIR1 homologues and several defence response genes like peroxidases, superoxide dismutase and thaumatin.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
5.
M. Jeuken R. van Wijk J. Peleman P. Lindhout 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(4):638-647
AFLP markers were obtained with 12 EcoRI/ MseI primer combinations on two independent F2 populations of Lactuca sativa ×Lactuca saligna. The polymorphism rates of the AFLP products between the two different L. saligna lines was 39%, between the two different L. sativa cultivars 13% and between the L. sativa and L. saligna parents on average 81%. In both F2 populations segregation distortion was found, but only Chromosome 5 showed skewness that was similar for both populations.
Two independent genetic maps of the two F2 populations were constructed that could be integrated due to the high similarity in marker order and map distances of 124
markers common to both populations. The integrated map consisted of 476 AFLP markers and 12 SSRs on nine linkage groups spanning
854 cM. The AFLP markers on the integrated map were randomly distributed with an average spacing between markers of 1.8 cM
and a maximal distance of 16 cM. Furthermore, the AFLP markers did not show severe clustering. This AFLP map provides good
opportunities for use in QTL mapping and marker-assisted selection.
Received: 13 July 2000 / Accepted: 19 January 2001 相似文献
6.
Tomato chromosome 6: a high resolution map of the long arm and construction of a composite integrated marker-order map 总被引:4,自引:0,他引:4
M. F. van Wordragen R. L. Weide E. Coppoolse P. Zabel M. Koornneef 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(8):1065-1072
Integration of molecular and classical genetic maps is an essential requirement for marker-assisted breeding, quantitative trait locus mapping and map-based cloning. With respects to tomato, such maps are only available for the top part of chromosome 1, for chromosome 3 and for the short arm and the centromere proximal part of the long arm of chromosome 6. Employing an L. esculentum line carrying an L. hirsutum introgression we constructed an integrated linkage map for the telomere proximal part of the long arm of tomato chromosome 6, thereby completing the integrated map published previously. With an average map distance of only 0.6 cM the map provides detailed information on the relative position of molecular markers and several traits of economical importance, such as the fruit color marker B. Furthermore, two additional crosses using lines containing L. pennellii introgressions were performed to address the question as to how the recombination frequency in a marked interval on the long arm of chromosome 6 is affected by introgressed segments from different origins. It is concluded that recombination is not merely affected by the local level of homology but also by surrounding sequences. Combination of all the linkage data generated in various crosses described in this and other studies enabled the construction of the first integrated map of an entire tomato chromosome. This map carries 42 loci and shows the position of 15 classical genes relative to 59 molecular markers. 相似文献
7.
A microsatellite marker based linkage map of tobacco 总被引:4,自引:0,他引:4
Bindler G van der Hoeven R Gunduz I Plieske J Ganal M Rossi L Gadani F Donini P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(2):341-349
We report the first linkage map of tobacco (Nicotiana tabacum L.) generated through microsatellite markers. The microsatellite markers were predominantly derived from genomic sequences
of the Tobacco Genome Initiative (TGI) through bioinformatics screening for microsatellite motives. A total of 684 primer
pairs were screened for functionality in a panel of 16 tobacco lines. Of those, 637 primer pairs were functional. Potential
parents for mapping populations were evaluated for their polymorphism level through genetic similarity analysis. The similarity
analysis revealed that the known groups of tobacco varieties (Burley, Flue-cured, Oriental and Dark) form distinct clusters.
A mapping population, based on a cross between varieties Hicks Broad Leaf and Red Russian, and consisting of 186 F2 individuals,
was selected for mapping. A total of 282 functional microsatellite markers were polymorphic in this population and 293 loci
could be mapped together with the morphological trait flower color. Twenty-four tentative linkage groups spanning 1,920 cM
could be identified. This map will provide the basis for the genetic mapping of traits in tobacco and for further analyses
of the tobacco genome.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
8.
Molecular mapping of quantitative trait loci in japonica rice. 总被引:1,自引:0,他引:1
Rice (Oryza sativa L.) molecular maps have previously been constructed using interspecific crosses or crosses between the two major subspecies: indica and japonica. For japonica breeding programs, however, it would be more suitable to use intrasubspecific crosses. A linkage map of 129 random amplified polymorphic DNA (RAPD) and 18 restriction fragment length polymorphism (RFLP) markers was developed using 118 F2 plants derived from a cross between two japonica cultivars with high and low seedling vigor, Italica Livorno (IL) and Labelle (LBL), respectively. The map spanned 980.5 cM (Kosambi function) with markers on all 12 rice chromosomes and an average distance of 7.6 cM between markers. Codominant (RFLP) and coupling phase linkages (among RAPDs) accounted for 79% of total map length and 71% of all intervals. This map contained a greater percentage of markers on chromosome 10, the least marked of the 12 rice chromosomes, than other rice molecular maps, but had relatively fewer markers on chromosomes 1 and 2. We used this map to detect quantitative trait loci (QTL) for four seedling vigor related traits scored on 113 F3 families in a growth chamber slantboard test at 18 degrees C. Two coleoptile, five root, and five mesocotyl length QTLs, each accounting for 9-50% of the phenotypic variation, were identified by interval analysis. Single-point analysis confirmed interval mapping results and detected additional markers significantly influencing each trait. About two-thirds of alleles positive for the putative QTLs were from the high-vigor parent, IL. One RAPD marker (OPAD13720) was associated with a IL allele that accounted for 18.5% of the phenotypic variation for shoot length, the most important determinant of seedling vigor in water-seeded rice. Results indicate that RAPDs are useful for map development and QTL mapping in rice populations with narrow genetic base, such as those derived from crosses among japonica cultivars. Other potential uses of the map are discussed. Key words : QTL mapping, RAPD, RFLP, seedling vigor, japonica, Oryza sativa. 相似文献
9.
10.
Small abalone, Haliotis diversicolor, is naturally distributed along the coastal waters of East Asia from Japan to the Philippines. It is an economically important
maricultured species in southern China and Taiwan. Genetic linkage maps for small abalone were constructed using a total of
308 simple sequence repeat markers including 297 novel markers. Segregation data on 96 progeny were genotyped using a pseudo-testcross
strategy. Sixteen linkage groups were identified in both female and male maps, consistent with the haploid chromosome number.
The female linkage map covered 758.3 cM, with an average interval of 5.2 cM. The male linkage map spanned a total genetic
distance of 676.2 cM, with an average interval of 4.5 cM. An integrated map was constructed by incorporating the homologous
parental linkage groups, resulting in 16 linkage groups with a total of 762.1 cM. Genome coverage of the integrated linkage
map was approximately 80.7%. The genetic linkage maps of small abalone may facilitate marker-assisted selection and quantitative
trait loci mapping. 相似文献
11.
Tsukasa Nunome Satomi Negoro Izumi Kono Hiroyuki Kanamori Koji Miyatake Hirotaka Yamaguchi Akio Ohyama Hiroyuki Fukuoka 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(6):1143-1153
Eggplant (Solanum melongena L.), also known as aubergine or brinjal, is an important vegetable in many countries. Few useful molecular markers have been
reported for eggplant. We constructed simple sequence repeat (SSR)-enriched genomic libraries in order to develop SSR markers,
and sequenced more than 14,000 clones. From these sequences, we designed 2,265 primer pairs to flank SSR motifs. We identified
1,054 SSR markers from amplification of 1,399 randomly selected primer pairs. The markers have an average polymorphic information
content of 0.27 among eight lines of S. melongena. Of the 1,054 SSR markers, 214 segregated in an intraspecific mapping population. We constructed cDNA libraries from several
eggplant tissues and obtained 6,144 expressed sequence tag (EST) sequences. From these sequences, we designed 209 primer pairs,
7 of which segregated in the mapping population. On the basis of the segregation data, we constructed a linkage map, and mapped
the 236 segregating markers to 14 linkage groups. The linkage map spans a total length of 959.1 cM, with an average marker
distance of 4.3 cM. The markers should be a useful resource for qualitative and quantitative trait mapping and for marker-assisted
selection in eggplant breeding. 相似文献
12.
J. B. Clarke D. J. Sargent R. I. Bošković A. Belaj K. R. Tobutt 《Tree Genetics & Genomes》2009,5(1):41-51
One hundred and sixty microsatellite (simple sequence repeat (SSR)) and six gene-specific markers revealing 174 loci were
scored in 94 seedlings from the inter-specific cross of Prunus avium ‘Napoleon’ × Prunus nipponica accession F1292. The co-segregation data from these markers were used to construct a linkage map for cherry which spanned
680 cM over eight linkage groups with an average marker spacing of 3.9 cM per marker and just six gaps longer than 15 cM.
Markers previously mapped in Prunus dulcis ‘Texas’ × Prunus persica ‘Earlygold’ allowed the cherry map to be anchored to the peach × almond map and showed the high level of synteny between
the species. Eighty-four loci segregated in P. avium ‘Napoleon’ versus 159 in P. nipponica. The segregations of 32 isoenzyme loci in a subset of 47 seedlings from the progeny were scored, using polyacrylamide gel
electrophoresis and/or isoelectric focusing separation followed by activity staining, and the co-segregation data were analysed
along with those for 39 isoenzymes reported previously and for the 174 sequence-tagged site loci plus an additional two SSR
loci. The second map incorporates 233 loci and spans 736 cM over eight linkage groups with an average marker spacing of 3.2 cM
per marker and just two gaps greater than 15 cM. The microsatellite map will provide a useful tool for cherry breeding and
marker-assisted selection and for synteny studies within Prunus; the gene-specific markers and isoenzymes will be useful for comparisons with maps of other rosaceous fruit crops.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
13.
14.
Ngoot-Chin Ting Johannes Jansen Sean Mayes Festo Massawe Ravigadevi Sambanthamurthi Leslie Cheng-Li Ooi Cheuk Weng Chin Xaviar Arulandoo Tzer-Ying Seng Sharifah Shahrul Rabiah Syed Alwee Maizura Ithnin Rajinder Singh 《BMC genomics》2014,15(1)
Background
Oil palm is an important perennial oil crop with an extremely long selection cycle of 10 to 12 years. As such, any tool that speeds up its genetic improvement process, such as marker-assisted breeding is invaluable. Previously, genetic linkage maps based on AFLP, RFLP and SSR markers were developed and QTLs for fatty acid composition and yield components identified. High density genetic maps of crosses of different genetic backgrounds are indispensable tools for investigating oil palm genetics. They are also useful for comparative mapping analyses to identify markers closely linked to traits of interest.Results
A 4.5 K customized oil palm SNP array was developed using the Illumina Infinium platform. The SNPs and 252 SSRs were genotyped on two mapping populations, an intraspecific cross with 87 palms and an interspecific cross with 108 palms. Parental maps with 16 linkage groups (LGs), were constructed for the three fruit forms of E. guineensis (dura, pisifera and tenera). Map resolution was further increased by integrating the dura and pisifera maps into an intraspecific integrated map with 1,331 markers spanning 1,867 cM. We also report the first map of a Colombian E. oleifera, comprising 10 LGs with 65 markers spanning 471 cM. Although not very dense due to the high level of homozygosity in E. oleifera, the LGs were successfully integrated with the LGs of the tenera map. Direct comparison between the parental maps identified 603 transferable markers polymorphic in at least two of the parents. Further analysis revealed a high degree of marker transferability covering 1,075 cM, between the intra- and interspecific integrated maps. The interspecific cross displayed higher segregation distortion than the intraspecific cross. However, inclusion of distorted markers in the genetic maps did not disrupt the marker order and no map expansion was observed.Conclusions
The high density SNP and SSR-based genetic maps reported in this paper have greatly improved marker density and genome coverage in comparison with the first reference map based on AFLP and SSR markers. Therefore, it is foreseen that they will be more useful for fine mapping of QTLs and whole genome association mapping studies in oil palm.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-309) contains supplementary material, which is available to authorized users. 相似文献15.
L. Gentzbittel E. Mestries S. Mouzeyar F. Mazeyrat S. Badaoui F. Vear D. Tourvieille de Labrouhe P. Nicolas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):218-234
A map of the sunflower genome, based on expressed sequences and consisting of 273 loci, was constructed. The map incorporates
data from seven F2 populations, for a total of 1115 individuals. Two hundred and fourty five loci corresponding to 170 anonymous cDNA markers
and four loci for morphological markers were mapped. We also mapped 18 loci corresponding to previously described genes or
to sequences obtained through homology cloning. The unit maps vary from 774 cM to 1060 cM, with an average value of 14 major
linkage groups. The integrated map is arranged in 17 major linkage groups including 238 loci, plus four small segments with
2–5 marker loci; and covers 1573 cM with an overall average marker interval of 7 cM. Thirty five percent of the markers were
dominant in nature and 30% showed inter-linkage group duplication without any indication of homoeologous linkage groups. Evidence
is provided for the independence of two distinct fertility restoration genes, for the presence of two loosely linked branching
loci, and for marker tightly linked to the Rf1 restoration locus. This map provides an efficient tool in breeding applications such as disease-resistance mapping, QTL analyses
and marker-assisted selection.
Received: 27 August 1998 / Accepted: 28 December 1998 相似文献
16.
Blair MW Pedraza F Buendia HF Gaitán-Solís E Beebe SE Gepts P Tohme J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(8):1362-1374
A total of 150 microsatellite markers developed for common bean (Phaseolus vulgaris L.) were tested for parental polymorphism and used to determine the positions of 100 genetic loci on an integrated genetic map of the species. The value of these single-copy markers was evident in their ability to link two existing RFLP-based genetic maps with a base map developed for the Mesoamerican × Andean population, DOR364 × G19833. Two types of microsatellites were mapped, based respectively on gene-coding and anonymous genomic-sequences. Gene-based microsatellites proved to be less polymorphic (46.3%) than anonymous genomic microsatellites (64.3%) between the parents of two inter-genepool crosses. The majority of the microsatellites produced single bands and detected single loci, however four of the gene-based and three of the genomic microsatellites produced consistent double or multiple banding patterns and detected more than one locus. Microsatellite loci were found on each of the 11 chromosomes of common bean, the number per chromosome ranging from 5 to 17 with an average of ten microsatellites each. Total map length for the base map was 1,720 cM and the average chromosome length was 156.4 cM, with an average distance between microsatellite loci of 19.5 cM. The development of new microsatellites from sequences in the Genbank database and the implication of these results for genetic mapping, quantitative trait locus analysis and marker-assisted selection in common bean are described.Communicated by H.F. Linskens 相似文献
17.
Manli Li Nana Yuyama Mariko Hirata Yunwen Wang Jianguo Han Hongwei Cai 《Molecular breeding : new strategies in plant improvement》2010,26(3):467-476
Japanese lawngrass (Zoysia japonica) and Manila grass (Z. matrella) are the two most important and commonly used Zoysia species. A consensus based SSR linkage map was developed for the genus by combining maps from each species. This used previously
constructed maps for two Z. japonica populations and a new map from Z. matrella. The new SSR linkage map for Z. matrella was based on 86 F2 individuals and contained 213 loci and covered a map distance of 1,351.2 cM in 32 linkage groups. Comparison of the three
linkage maps constructed from populations with different genetic backgrounds indicated that most markers exhibited a consensus
order, although some intervals or regions displayed discrepancy in marker orders or positions. The integrated map comprises
507 loci with a mean interval of 4.1 cM, covering a map distance of 2,066.6 cM in 22 linkage groups. The SSR-based map will
allow marker-assisted selection and be useful for the mapping and cloning of economically important genes or quantitative
trait loci. 相似文献
18.
Amplified fragment length polymorphism mapping of quantitative trait loci for malaria parasite susceptibility in the yellow fever mosquito Aedes aegypti
下载免费PDF全文
![点击此处可从《Genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The yellow fever mosquito Aedes aegypti has been the subject of extensive genetic research due to its medical importance and the ease with which it can be manipulated in the laboratory. A molecular genetic linkage map was constructed using 148 amplified fragment length polymorphism (AFLP) and six single-strand conformation polymorphism (SSCP) markers. Eighteen AFLP primer combinations were used to genotype two reciprocal F2 segregating populations. Each primer combination generated an average of 8.2 AFLP markers eligible for linkage mapping. The length of the integrated map was 180.9 cM, giving an average marker resolution of 1.2 cM. Composite interval mapping revealed a total of six QTL significantly affecting Plasmodium susceptibility in the two reciprocal crosses of Ae. aegypti. Two common QTL on linkage group 2 were identified in both crosses that had similar effects on the phenotype, and four QTL were unique to each cross. In one cross, the four main QTL accounted for 64% of the total phenotypic variance, and digenic epistasis explained 11.8% of the variance. In the second cross, the four main QTL explained 66% of the variance, and digenic epistasis accounted for 16% of the variance. The actions of these QTL were either dominance or underdominance. Our results indicated that at least three new QTL were mapped on chromosomes 1 and 3. The polygenic nature of susceptibility to P. gallinaceum and epistasis are important factors for significant variation within or among mosquito strains. The new map provides additional information useful for further genetic investigation, such as identification of new genes and positional cloning. 相似文献
19.
V. Lombard R. Delourme 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(4):491-507
A framework consensus map for rapeseed (Brassica napus L.) was constructed from the integration of three DH mapping populations derived from crosses between or within spring- and
winter-type parents. Several sources of genetic markers were used: isozymes, RFLPs, RAPDs, and AFLPs. A total of 992 different
markers were mapped to at least one population, of which 540 were included in the consensus map and 253 were common to at
least two populations. Markers were distributed over 19 linkage groups, thus reflecting the basic chromosome number of rapeseed
and covered 2,429 cM, which was in the mean confidence-interval estimates of genome length (2,127–2,480) cM. Markers were
evenly spaced on the entire genome even if, for several linkage groups, both RAPD and AFLP markers were not uniformly distributed.
In the population resulting from a cross between two spring lines, a higher recombination rate was observed and a translocation
was identified. The consensus approach allowed to map a larger number of markers, to obtain a near-complete coverage of the
rapeseed genome, to fill the number of gaps, and to consolidate the linkage groups of the individual maps.
Received: 19 July 2000 / Accepted: 31 October 2000 相似文献
20.
Garcia AA Kido EA Meza AN Souza HM Pinto LR Pastina MM Leite CS Silva JA Ulian EC Figueira A Souza AP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(2):298-314
Sugarcane (Saccharum spp.) is a clonally propagated outcrossing polyploid crop of great importance in tropical agriculture. Up to now, all sugarcane
genetic maps had been developed using either full-sib progenies derived from interspecific crosses or from selfing, both approaches
not directly adopted in conventional breeding. We have developed a single integrated genetic map using a population derived
from a cross between two pre-commercial cultivars (‘SP80-180’ × ‘SP80-4966’) using a novel approach based on the simultaneous
maximum-likelihood estimation of linkage and linkage phases method specially designed for outcrossing species. From a total
of 1,118 single-dose markers (RFLP, SSR and AFLP) identified, 39% derived from a testcross configuration between the parents
segregating in a 1:1 fashion, while 61% segregated 3:1, representing heterozygous markers in both parents with the same genotypes.
The markers segregating 3:1 were used to establish linkage between the testcross markers. The final map comprised of 357 linked
markers, including 57 RFLPs, 64 SSRs and 236 AFLPs that were assigned to 131 co-segregation groups, considering a LOD score
of 5, and a recombination fraction of 37.5 cM with map distances estimated by Kosambi function. The co-segregation groups
represented a total map length of 2,602.4 cM, with a marker density of 7.3 cM. When the same data were analyzed using JoinMap
software, only 217 linked markers were assigned to 98 co-segregation groups, spanning 1,340 cM, with a marker density of 6.2 cM.
The maximum-likelihood approach reduced the number of unlinked markers to 761 (68.0%), compared to 901 (80.5%) using JoinMap.
All the co-segregation groups obtained using JoinMap were present in the map constructed based on the maximum-likelihood method.
Differences on the marker order within the co-segregation groups were observed between the two maps. Based on RFLP and SSR
markers, 42 of the 131 co-segregation groups were assembled into 12 putative homology groups. Overall, the simultaneous maximum-likelihood
estimation of linkage and linkage phases was more efficient than the method used by JoinMap to generate an integrated genetic
map of sugarcane.
E.A. Kido, A.N. Meza and H.M.B. Souza contributed equally to this work. 相似文献