A genetic linkage map for Arctic char (Salvelinus alpinus): evidence for higher recombination rates and segregation distortion in hybrid versus pure strain mapping parents

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 304-315 ◽  
Author(s):  
R A Woram ◽  
C McGowan ◽  
J A Stout ◽  
K Gharbi ◽  
M M Ferguson ◽  
...  
Keyword(s):  
Linkage Map ◽  
Segregation Distortion ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Salvelinus Alpinus ◽  
Linkage Groups ◽  
Recombination Rates ◽  
Pure Strain ◽  
Female Hybrid ◽  
Map Distance

We constructed a genetic linkage map for Arctic char (Salvelinus alpinus) using two backcrosses between genetically divergent strains. Forty-six linkage groups (expected = 39–41) and 19 homeologous affinities (expected = 25) were identified using 184 microsatellites, 129 amplified fragment length polymorphisms (AFLPs), 13 type I gene markers, and one phenotypic marker, SEX. Twenty-six markers remain unlinked. Female map distance (9.92 Morgans) was substantially higher than male map distance (3.90 Morgans) based on the most complete parental information (i.e., the F1 hybrids). Female recombination rates were often significantly higher than those of males across all pairwise comparisons within homologous chromosomal segments (average female to male ratios within families was 1.69:1). The female hybrid parent had significantly higher recombination rates than the pure strain female parent. Segregation distortion was detected in four linkage groups (4, 8, 13, 20) for both families. In family 3, only the largest fish were sampled for genotyping, suggesting that segregation distortion may represent regions possessing influences on growth. In family 2, almost all cases showing segregation distortion involved markers in the female hybrid parent.Key words: salmonid fishes, polyploidy, homeology, genetic markers.

Two genetic linkage maps of mungbean using RFLP and RAPD markers

2000 ◽  
Vol 51 (4) ◽  
pp. 415 ◽  
Author(s):  
C. J. Lambrides ◽  
R. J. Lawn ◽  
I. D. Godwin ◽  
J. Manners ◽  
B. C. Imrie
Keyword(s):  
Linkage Map ◽  
Segregation Distortion ◽  
Recombinant Inbred ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Rflp Markers ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Genetic Linkage Maps ◽  
Map Distance

Two genetic linkage maps of mungbean derived from the cross Berken ACC 41 are reported. The F2 map constructed from 67 individuals consisted of 110 markers (52 RFLP and 56 RAPD) that grouped into 12 linkage groups. The linked markers spanned a total map distance of 758.3 cM. A recombinant inbred (RI) population derived from the 67 F2 individuals was used for the generation of an additional linkage map. The RI map, composed entirely of RAPD markers, consisted of 115 markers in 12 linkage groups. The linked markers spanned a total map distance of 691.7 cM. Using a framework set of RFLP markers, the F2 map was compared with another F2 mungbean map constructed in Minnesota. In general, the order of these markers was consistent between maps. Segregation distortion was observed for some markers. 14.5% (16/110) of mapped F2 markers and 24% (28/115) of mapped RI markers segregated with distorted ratios. Segregation distortion occurred in each successive generation after the F2 . The regions of distortion identified in the Australian maps did not coincide with regions of the Minnesota map.

A genetic linkage map for Stevia rebaudiana

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Y Yao ◽  
M Ban ◽  
J Brandle
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Genetic Linkage Map ◽  
Average Distance ◽  
Stevia Rebaudiana ◽  
Linkage Groups ◽  
Genome Map ◽  
High Level ◽  
Map Distance

To lay a foundation for molecular breeding efforts, the first genetic linkage map for Stevia rebaudiana has been constructed using segregation data from a pseudo test-cross F1 population. A total of 183 randomly amplified polymorphic DNA (RAPD) markers were analysed and assembled into 21 linkage groups covering a total distance of 1389 cM, with an average distance between markers of of 7.6 cM. The 11 largest linkage groups consisted of 4-19 loci, ranged in length from 56 to 174 cM, and accounted for 75% of the total map distance. Fifteen RAPD loci were found to be unlinked. From the 521 primers showing amplification products, 185 (35.5%) produced a total of 293 polymorphic fragments, indicating a high level of genetic diversity in stevia. Most of the RAPD markers in stevia segregated in normal Mendelian fashion.Key words: stevia, open-pollinated, genome map, RAPD.

A genetic linkage map of crested wheatgrass based on AFLP and RAPD markers

Genome ◽  
2012 ◽  
Vol 55 (4) ◽  
pp. 327-335 ◽  
Author(s):  
Xiaoxia Yu ◽  
Xiaolei Li ◽  
Yanhong Ma ◽  
Zhuo Yu ◽  
Zaozhe Li
Keyword(s):  
Molecular Markers ◽  
Linkage Map ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Genetic Linkage Map ◽  
Mapping Population ◽  
Gene Localization ◽  
Linkage Groups ◽  
Crested Wheatgrass ◽  
Map Distance

Using a population of 105 interspecific F2 hybrids derived from a cross between Agropyron mongolicum Keng and Agropyron cristatum (L.) Gaertn. ‘Fairway’ as a mapping population, a genetic linkage map of crested wheatgrass was constructed based on AFLP and RAPD molecular markers. A total of 175 markers, including 152 AFLP and 23 RAPD markers, were ordered in seven linkage groups. The map distance was 416 cM, with a mean distance of 2.47 cM between markers. The number of markers ranged from 13 to 46 in each linkage group and the length of groups ranged from 18 to 104 cM. The research found that 30 out of 175 molecular markers showed segregation distortion, accounting for 17% of all markers. This is the first genetic linkage map of crested wheatgrass. This map will facilitate gene localization, cloning, and molecular marker-assisted selection in the future.

RFLP mapping in Brassica nigra indicates differing recombination rates in male and female meioses

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Ulf Lagercrantz ◽  
Derek J. Lydiate
Keyword(s):  
Sex Differences ◽  
Linkage Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Brassica Nigra ◽  
Recurrent Parent ◽  
Linkage Groups ◽  
Recombination Rates ◽  
Male Recombination ◽  
Male And Female

A genetic linkage map of Brassica nigra, comprised of 288 loci in eight linkage groups, was constructed. The linkage groups varied in size from 72 to 159 cM and the total map length was 855 cM. The recurrent parent used in the backcross was extremely heterozygous. This allowed recombination to be estimated separately for female (recurrent parent) meiosis and male (F1) meiosis over a large proportion of the genome. Significant differences between male and female recombination frequencies were observed on all six linkage groups where data was available for both sexes. Enhanced male recombination frequencies were observed that were associated with proterminal regions, while enhanced female recombination frequencies were adjacent to putative centromeres. It is possible that the distinct genotypes of the F1 (male) and recurrent (female) parents contributed to the observed differences in recombination. However, this study emphasizes the need to consider potential sex differences, in both the rate and the position of recombination, when planning genetic experiments and breeding programmes.Key words: genetic map, sex dependent recombination, centromeres, telomeres.

The First Comprehensive Genetic Linkage Map of a Marsupial: The Tammar Wallaby (Macropus eugenii)

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 321-330 ◽  
Author(s):  
Kyall R Zenger ◽  
Louise M McKenzie ◽  
Desmond W Cooper
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Average Distance ◽  
Tammar Wallaby ◽  
Chromosome 1 ◽  
Linkage Groups ◽  
Recombination Rates ◽  
Macropus Eugenii ◽  
Significant Linkage

AbstractThe production of a marsupial genetic linkage map is perhaps one of the most important objectives in marsupial research. This study used a total of 353 informative meioses and 64 genetic markers to construct a framework genetic linkage map for the tammar wallaby (Macropus eugenii). Nearly all markers (93.8%) formed a significant linkage (LOD > 3.0) with at least one other marker, indicating that the majority of the genome had been mapped. In fact, when compared with chiasmata data, >70% (828 cM) of the genome has been covered. Nine linkage groups were identified, with all but one (LG7; X-linked) allocated to the autosomes. These groups ranged in size from 15.7 to 176.5 cM and have an average distance of 16.2 cM between adjacent markers. Of the autosomal linkage groups (LGs), LG2 and LG3 were assigned to chromosome 1 and LG4 localized to chromosome 3 on the basis of physical localization of genes. Significant sex-specific distortions toward reduced female recombination rates were revealed in 22% of comparisons. When comparing the X chromosome data to closely related species it is apparent that they are conserved in both synteny and gene order.

scholarly journals Genetic Linkage Map of the Edible BasidiomycetePleurotus ostreatus

2000 ◽  
Vol 66 (12) ◽  
pp. 5290-5300 ◽  
Author(s):  
Luis M. Larraya ◽  
G�mer P�rez ◽  
Enrique Ritter ◽  
Antonio G. Pisabarro ◽  
Lucı́a Ramı́rez
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Gene Sequence ◽  
Genetic Linkage Map ◽  
Fragment Length Polymorphism ◽  
Individual Cell ◽  
Random Amplified Polymorphic Dna ◽  
Rrna Gene ◽  
Linkage Groups ◽  
Rrna Gene Sequence

ABSTRACT We have constructed a genetic linkage map of the edible basidiomycete Pleurotus ostreatus (var. Florida). The map is based on the segregation of 178 random amplified polymorphic DNA and 23 restriction fragment length polymorphism markers; four hydrophobin, two laccase, and two manganese peroxidase genes; both mating type loci; one isozyme locus (est1); the rRNA gene sequence; and a repetitive DNA sequence in a population of 80 sibling monokaryons. The map identifies 11 linkage groups corresponding to the chromosomes ofP. ostreatus, and it has a total length of 1,000.7 centimorgans (cM) with an average of 35.1 kbp/cM. The map shows a high correlation (0.76) between physical and genetic chromosome sizes. The number of crossovers observed per chromosome per individual cell is 0.89. This map covers nearly the whole genome of P. ostreatus.

A high-density genetic linkage map of a black spruce (Picea mariana) × red spruce (Picea rubens) interspecific hybrid

Genome ◽  
2011 ◽  
Vol 54 (2) ◽  
pp. 128-143 ◽  
Author(s):  
Bum-Yong Kang ◽  
John E. Major ◽  
Om P. Rajora
Keyword(s):  
Picea Mariana ◽  
Interspecific Hybrid ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Black Spruce ◽  
Picea Rubens ◽  
Red Spruce ◽  
Linkage Groups ◽  
Genomic Resource ◽  
Map Distance

Genetic maps provide an important genomic resource of basic and applied significance. Spruce ( Picea ) has a very large genome size (between 0.85 × 1010 and 2.4 × 1010 bp; 8.5–24.0 pg/1C, a mean of 17.7 pg/1C ). We have constructed a near-saturated genetic linkage map for an interspecific backcross (BC1) hybrid of black spruce (BS; Picea mariana (Mill.) B.S.P.) and red spruce (RS; Picea rubens Sarg.), using selectively amplified microsatellite polymorphic loci (SAMPL) markers. A total of 2284 SAMPL markers were resolved using 31 SAMPL–MseI selective nucleotide primer combinations. Of these, 1216 SAMPL markers showing Mendelian segregation were mapped, whereas 1068 (46.8%) SAMPL fragments showed segregation distortion at α = 0.05. Maternal, paternal, and consensus maps consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12) of 12 in the genus Picea. The maternal BS map consisted of 814 markers distributed over 12 linkage groups, covering 1670 cM, with a mean map distance of 2.1 cM between adjacent markers. The paternal BS × RS map consisted of 773 markers distributed over 12 linkage groups, covering 1563 cM, with a mean map distance of 2.0 cM between adjacent markers. The consensus interspecific hybrid BC1 map consisted of 1216 markers distributed over 12 linkage groups, covering 1865 cM (98% genome coverage), with a mean map distance of 1.5 cM between adjacent markers. The genetic map reported here provides an important genomic resource in Picea, Pinaceae, and conifers.

Mapping of quantitative trait loci underlying resistance to cassava anthracnose disease

2015 ◽  
Vol 154 (7) ◽  
pp. 1209-1217 ◽  
Author(s):  
A. BOONCHANAWIWAT ◽  
S. SRAPHET ◽  
S. WHANKAEW ◽  
O. BOONSENG ◽  
D. R. SMITH ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Linkage Map ◽  
Dna Markers ◽  
Quantitative Trait ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Gene Annotation ◽  
Linkage Groups ◽  
Anthracnose Disease ◽  
Trait Loci

SUMMARYCassava (Manihot esculenta Crantz) is an economically important root crop in Thailand, which is ranked the world's top cassava exporting country. Production of cassava can be hampered by several pathogens and pests. Cassava anthracnose disease (CAD) is an important disease caused by the fungus Colletotrichum gloeosporioides f. sp. manihotis. The pathogen causes severe stem damage resulting in yield reductions and lack of stem cuttings available for planting. Molecular studies of cassava response to CAD will provide useful information for cassava breeders to develop new varieties with resistance to the disease. The current study aimed to identify quantitative trait loci (QTL) and DNA markers associated with resistance to CAD. A total of 200 lines of two F1 mapping populations were generated by reciprocal crosses between the varieties Huabong60 and Hanatee. The F1 samples were genotyped based on simple sequence repeat (SSR) and expressed sequence tag-SSR markers and a genetic linkage map was constructed using the JoinMap®/version3·0 program. The results showed that the map consisted of 512 marker loci distributed on 24 linkage groups with a map length of 1771·9 centimorgan (cM) and a mean interval between markers of 5·7 cM. The genetic linkage map was integrated with phenotypic data for the response to CAD infection generated by a detached leaf assay test. A total of three QTL underlying the trait were identified on three linkage groups using the MapQTL®/version4·0 program. Those DNA markers linked to the QTL that showed high statistically significant values with the CAD resistance trait were identified for gene annotation analysis and 23 candidate resistance genes to CAD infection were identified.

scholarly journals Development of a genetic linkage map for Sharon goatgrass (Aegilops sharonensis) and mapping of a leaf rust resistance gene

Genome ◽  
2013 ◽  
Vol 56 (7) ◽  
pp. 367-376 ◽  
Author(s):  
P.D. Olivera ◽  
A. Kilian ◽  
P. Wenzl ◽  
B.J. Steffenson
Keyword(s):  
Linkage Map ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Chromosomal Location ◽  
Dominant Gene ◽  
Leaf Rust Resistance Gene ◽  
Linkage Groups ◽  
Aegilops Sharonensis

Aegilops sharonensis (Sharon goatgrass), a diploid wheat relative, is known to be a rich source of disease resistance genes for wheat improvement. To facilitate the transfer of these genes into wheat, information on their chromosomal location is important. A genetic linkage map of Ae. sharonensis was constructed based on 179 F2 plants derived from a cross between accessions resistant (1644) and susceptible (1193) to wheat leaf rust. The linkage map was based on 389 markers (377 Diversity Arrays Technology (DArT) and 12 simple sequence repeat (SSR) loci) and was comprised of 10 linkage groups, ranging from 2.3 to 124.6 cM. The total genetic length of the map was 818.0 cM, with an average interval distance between markers of 3.63 cM. Based on the chromosomal location of 115 markers previously mapped in wheat, the four linkage groups of A, B, C, and E were assigned to Ae. sharonensis (Ssh) and homoeologous wheat chromosomes 6, 1, 3, and 2. The single dominant gene (designated LrAeSh1644) conferring resistance to leaf rust race THBJ in accession 1644 was positioned on linkage group A (chromosome 6Ssh) and was flanked by DArT markers wpt-9881 (at 1.9 cM distal from the gene) and wpt-6925 (4.5 cM proximal). This study clearly demonstrates the utility of DArT for genotyping uncharacterized species and tagging resistance genes where pertinent genomic information is lacking.

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