Identification of the A and C genomes of amphidiploid Brassica napus (oilseed rape)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1122-1131 ◽  
Author(s):  
I. A. P. Parkin ◽  
A. G. Sharpe ◽  
D. J. Keith ◽  
D. J. Lydiate
Keyword(s):  
Brassica Napus ◽  
Linkage Map ◽  
Oilseed Rape ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Resynthesized Brassica Napus ◽  
Disomic Inheritance ◽  
A Genome ◽  
C Genome ◽  
Homoeologous Chromosomes

A genetic linkage map consisting of 399 RFLP-defined loci was generated from a cross between resynthesized Brassica napus (an interspecific B. rapa × B. oleracea hybrid) and "natural" oilseed rape. The majority of loci exhibited disomic inheritance of parental alleles demonstrating that B. rapa chromosomes were each pairing exclusively with recognisable A-genome homologues in B. napus and that B. oleracea chromosomes were pairing similarly with C-genome homologues. This behaviour identified the 10 A genome and 9 C genome linkage groups of B. napus and demonstrated that the nuclear genomes of B. napus, B. rapa, and B. oleracea have remained essentially unaltered since the formation of the amphidiploid species, B. napus. A range of unusual marker patterns, which could be explained by aneuploidy and nonreciprocal translocations, were observed in the mapping population. These chromosome abnormalities were probably caused by associations between homoeologous chromosomes at meiosis in the resynthesized parent and the F1 plant leading to nondisjunction and homoeologous recombination.Key words: genetic linkage map, homoeologous recombination, Brassica rapa, Brassica oleracea, genome organization.

scholarly journals Construction of an integrated genetic linkage map for the A genome of Brassica napus using SSR markers derived from sequenced BACs in B. rapa

BMC Genomics ◽  
2010 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinsong Xu ◽  
Xiaoju Qian ◽  
Xiaofeng Wang ◽  
Ruiyuan Li ◽  
Xiaomao Cheng ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Linkage Map ◽  
Ssr Markers ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
A Genome

Frequent nonreciprocal translocations in the amphidiploid genome of oilseed rape (Brassica napus)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1112-1121 ◽  
Author(s):  
A. G. Sharpe ◽  
I. A. P. Parkin ◽  
D. J. Keith ◽  
D. J. Lydiate
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Doubled Haploid ◽  
Microspore Culture ◽  
Homoeologous Recombination ◽  
Linkage Groups ◽  
Rflp Map ◽  
A Genome ◽  
C Genome ◽  
Marker Loci

A RFLP map of Brassica napus, consisting of 277 loci arranged in 19 linkage groups, was produced from genetic segregation in a combined population of 174 doubled-haploid microspore-derived lines. The integration of this map with a B. napus map derived from a resynthesized B. napus × oilseed rape cross allowed the 10 linkage groups of the B. napus A genome and the 9 linkage groups of the C genome to be identified. Collinear patterns of marker loci on different linkage groups suggested potential partial homoeologues. RFLP patterns consistent with aberrant chromosomes were observed in 9 of the 174 doubled-haploid lines. At least 4 of these lines carried nonreciprocal, homoeologous translocations. These translocations were probably the result of homoeologous recombination in the amphidiploid genome of oilseed rape, suggesting that domesticated B. napus is unable to control chromosome pairing completely. Evidence for genome homogenization in oilseed rape is presented and its implications on genetic mapping in amphidiploid species is discussed. The level of polymorphism in the A genome was higher than that in the C genome and this might be a general property of oilseed rape crosses.Key words: restriction fragment length polymorphism, genetic linkage map, homoeologous recombination, microspore culture, doubled haploid.

Genetics of isozyme loci in Brassica campestris L. and in the progeny of a trigenomic hybrid between B. napus L. and B. campestris L.

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 433-440 ◽  
Author(s):  
B. Y. Chen ◽  
W. K. Heneen ◽  
V. Slmonsen
Keyword(s):  
Brassica Campestris ◽  
Shikimate Dehydrogenase ◽  
Mendelian Segregation ◽  
Resynthesized Brassica Napus ◽  
Locus Pair ◽  
Disomic Inheritance ◽  
A Genome ◽  
C Genome ◽  
Isozyme Loci ◽  
Isozyme Analyses

F2 progeny of Brassica campestris crosses were analyzed for single-locus inheritance of glucosephosphate isomerase, leucine aminopeptidase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and shikimate dehydrogenase enzymes. In most of the F2 families, the observed inheritance data for six polymorphic isozyme loci coincided well with the ratios expected under Mendelian segregation of either codominant alleles or dominant-recessive alleles when a null allele was involved. Complete linkage was observed for one locus pair (Lap-2A/6Pgd-2Ac), with the recombination frequency estimated to be r ≈ 0.000. From isozyme analyses made on resynthesized Brassica napus (AACC) and the actual parents B. campestris (AA) and B. alboglabra (CC) and on a trigenomic hybrid (AAC) between B. napus and B. campestris, it was possible to recognize A and C genome specific isozyme loci through the nonoverlapping electrophoretic mobilities of alleles characteristic of each genome. The trigenomic hybrid was selfed and genetic analyses of the offspring indicated that the A genome specific isozyme loci displayed a normal disomic inheritance. The C genome specific isozyme loci, on the other hand, showed nonrandom loss in the aneuploid offspring, thereby indicating the nonrandom loss of C genome chromosomes. At least 4 of the 8 C genome specific isozyme loci studied were located on separate chromosomes. The apparent occurrence of multiplicates of certain isozyme loci supports the concept that duplication of structural nuclear genes prevails in the diploid Brassica genomes.Key words: isozymes, Brassica, inheritance, trigenomic hybrid (2n = 29, AAC), genome-specific isozyme loci.

Integration of Brassica A genome genetic linkage map between Brassica napus and B. rapa

Genome ◽  
2008 ◽  
Vol 51 (3) ◽  
pp. 169-176 ◽  
Author(s):  
Keita Suwabe ◽  
Colin Morgan ◽  
Ian Bancroft
Keyword(s):  
Molecular Markers ◽  
Linkage Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Linkage Groups ◽  
Indel Markers ◽  
A Genome ◽  
High Level ◽  
High Degree ◽  
Genetic Integration

An integrated linkage map between B. napus and B. rapa was constructed based on a total of 44 common markers comprising 41 SSR (33 BRMS, 6 Saskatoon, and 2 BBSRC) and 3 SNP/indel markers. Between 3 and 7 common markers were mapped onto each of the linkage groups A1 to A10. The position and order of most common markers revealed a high level of colinearity between species, although two small regions on A4, A5, and A10 revealed apparent local inversions between them. These results indicate that the A genome of Brassica has retained a high degree of colinearity between species, despite each species having evolved independently after the integration of the A and C genomes in the amphidiploid state. Our results provide a genetic integration of the Brassica A genome between B. napus and B. rapa. As the analysis employed sequence-based molecular markers, the information will accelerate the exploitation of the B. rapa genome sequence for the improvement of oilseed rape.

Latent S alleles are widespread in cultivated self-compatible Brassica napus

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 257-265 ◽  
Author(s):  
U U Ekuere ◽  
I A.P Parkin ◽  
C Bowman ◽  
D Marshall ◽  
D J Lydiate
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Self Incompatibility ◽  
S Locus ◽  
Winter Oilseed Rape ◽  
A Genome ◽  
C Genome ◽  
S Alleles ◽  
Crop Types ◽  
S Allele

The genetic control of self-incompatibility in Brassica napus was investigated using crosses between resynthesized lines of B. napus and cultivars of oilseed rape. These crosses introduced eight C-genome S alleles from Brassica oleracea (S16, S22, S23, S25, S29, S35, S60, and S63) and one A-genome S allele from Brassica rapa (SRM29) into winter oilseed rape. The inheritance of S alleles was monitored using genetic markers and S phenotypes were determined in the F1, F2, first backcross (B1), and testcross (T1) generations. Two different F1 hybrids were used to develop populations of doubled haploid lines that were subjected to genetic mapping and scored for S phenotype. These investigations identified a latent S allele in at least two oilseed rape cultivars and indicated that the S phenotype of these latent alleles was masked by a suppressor system common to oilseed rape. These latent S alleles may be widespread in oilseed rape varieties and are possibly associated with the highly conserved C-genome S locus of these crop types. Segregation for S phenotype in subpopulations uniform for S genotype suggests the existence of suppressor loci that influenced the expression of the S phenotype. These suppressor loci were not linked to the S loci and possessed suppressing alleles in oilseed rape and non-suppressing alleles in the diploid parents of resynthesized B. napus lines.Key words: self-incompatibility, B. oleracea, B. rapa, S locus, suppression.

Construction of genetic linkage map and mapping of QTL for seed color in Brassica rapa

Genome ◽  
2012 ◽  
Vol 55 (12) ◽  
pp. 813-823 ◽  
Author(s):  
Berisso Kebede ◽  
Kuljit Cheema ◽  
David L. Greenshields ◽  
Changxi Li ◽  
Gopalan Selvaraj ◽  
...  
Keyword(s):  
Linkage Map ◽  
Ssr Markers ◽  
Brassica Rapa ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Recombinant Inbred Lines ◽  
Phenotypic Variance ◽  
Environment Interaction ◽  
Seed Color ◽  
A Genome

A genetic linkage map of Brassica rapa L. was constructed using recombinant inbred lines (RILs) derived from a cross between yellow-seeded cultivar Sampad and a yellowish brown seeded inbred line 3-0026.027. The RILs were evaluated for seed color under three conditions: field plot, greenhouse, and controlled growth chambers. Variation for seed color in the RILs ranged from yellow, like yellow sarson, to dark brown/black even though neither parent had shown brown/black colored seeds. One major QTL (SCA9-2) and one minor QTL (SCA9-1) on linkage group (LG) A9 and two minor QTL (SCA3-1, SCA5-1) on LG A3 and LG A5, respectively, were detected. These collectively explained about 67% of the total phenotypic variance. SCA9-2 mapped in the middle of LG A9, explained about 55% phenotypic variance, and consistently expressed in all environments. The second QTL on LG A9 was ∼70 cM away from SCA9-2, suggesting that independent assortment of these QTLs is possible. A digenic epistatic interaction was found between the two main effect QTL on LG A9; and the epistasis × environment interaction was nonsignificant, suggesting stability of the interaction across the environments. The QTL effect on LG A9 was validated using simple sequence repeat (SSR) markers from the two QTL regions of this LG on a B1S1 population (F1 backcrossed to Sampad followed by self-pollination) segregating for brown and yellow seed color, and on their self-pollinated progenies (B1S2). The SSR markers from the QTL region SCA9-2 showed a stronger linkage association with seed color as compared with the marker from SCA9-1. This suggests that the QTL SCA9-2 is the major determinant of seed color in the A genome of B. rapa.

Genome-wide identification of silique-related traits based on high-density genetic linkage map in Brassica napus

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Weiguo Zhao ◽  
Lina Zhang ◽  
Hongbo Chao ◽  
Hao Wang ◽  
Na Ta ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Linkage Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
High Density ◽  
Genome Wide

scholarly journals A Second-Generation Genetic Linkage Map of the Domestic Dog, Canis familiaris

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 803-820 ◽  
Author(s):  
Mark W Neff ◽  
Karl W Broman ◽  
Cathryn S Mellersh ◽  
Kunal Ray ◽  
Gregory M Acland ◽  
...  
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Positional Cloning ◽  
Genetic Linkage Map ◽  
Domestic Dog ◽  
Disease Genes ◽  
A Genome ◽  
High Incidence ◽  
Genetic Length ◽  
And Behavior

Abstract Purebred strains, pronounced phenotypic variation, and a high incidence of heritable disease make the domestic dog uniquely suited to complement genetic analyses in humans and mice. A comprehensive genetic linkage map would afford many opportunities in dogs, ranging from the positional cloning of disease genes to the dissection of quantitative differences in size, shape, and behavior. Here we report a canine linkage map with the number of mapped loci expanded to 276 and 10-cM coverage extended to 75–90% of the genome. Most of the 38 canine autosomes are likely represented in the collection of 39 autosomal linkage groups. Eight markers were sufficiently informative to detect linkage at distances of 10–13 cM, yet remained unlinked to any other marker. Taken together, the results suggested a genome size of about 27 M. As in other species, the genetic length varied between sexes, with the female autosomal distance being ∼1.4-fold greater than that of male meioses. Fifteen markers anchored well-described genes on the map, thereby serving as landmarks for comparative mapping in dogs. We discuss the utility of the current map and outline steps necessary for future map improvement.

scholarly journals An intervarietal genetic linkage map of Indian bread wheat (Triticum aestivum L.) and QTL maps for some metric traits

2007 ◽  
Vol 89 (3) ◽  
pp. 165-179 ◽  
Author(s):  
E. NALINI ◽  
S. G. BHAGWAT ◽  
N. JAWALI
Keyword(s):  
Triticum Aestivum ◽  
Linkage Map ◽  
Bread Wheat ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Flag Leaf ◽  
D Genome ◽  
Wheat Varieties ◽  
A Genome ◽  
Metric Traits

SummaryBread wheat (Triticum aestivum L.) exhibits very narrow genetic diversity and hence there is high relatedness among cultivated varieties. However, a population generated from an intervarietal cross, with the parents differing in a large number of traits, could lead to the generation of QTL maps which will be useful in practice. In this report a genetic linkage map of wheat is constructed using a cross between two Indian bread wheat varieties: Sonalika and Kalyansona. The linkage map consisted of 236 markers and spanned a distance of 3639 cM, with 1211·2 cM for the A genome, 1669·2 cM for the B genome, 192·4 cM for the D genome and 566·2 cM for unassigned groups. Linkage analysis defined 37 linkage groups of which 24 were assigned to 17 chromosomes. The genetic map was used to identify QTLs by composite internal mapping (CIM) for three metric traits, viz. culm length (CL), flag leaf length (FLL) and flag leaf breadth (FLB). Of 25 QTLs identified in this study, 15 have not been reported previously. Multitrait CIM (MCIM) analysis was carried out for traits that were significantly correlated such as FLB–FLL and CL–FLB–FLL. Detection of a large number of QTLs for the three traits analysed suggests that in parent cultivars that are not too diverse, the differences at genetic level detected as polymorphisms may be mostly associated with QTLs for the observed differences.

Sign in / Sign up

Export Citation Format

Share Document