Production and genetic analysis of partial hybrids from intertribal sexual crosses between Brassica napus and Isatis indigotica and progenies

Genome ◽  
2010 ◽  
Vol 53 (2) ◽  
pp. 146-156 ◽  
Author(s):  
Y. Q. Tu ◽  
J. Sun ◽  
X. H. Ge ◽  
Z. Y. Li
Keyword(s):  
Brassica Napus ◽  
Genetic Analysis ◽  
Medicinal Plant ◽  
Chromosome Numbers ◽  
Chromosome Elimination ◽  
Low Fertility ◽  
Isatis Indigotica ◽  
A Genome ◽  
C Genome ◽  
Sexual Crosses

With the dye and medicinal plant Isatis indigotica (2n = 14) as pollen parent, intertribal sexual hybrids with Brassica napus (2n = 38, AACC) were obtained and characterized. Among a lot of F1 plants produced, only five hybrids (H1–H5) were distinguished morphologically from female B. napus parents by showing low fertility and some characters of I. indigotica, and also by having different chromosome numbers. H1–H4 had similar but variable chromosome numbers in their somatic and meiotic cells (2n = 25–30), and H5 had 2n = 19, the same number as the haploid of B. napus. GISH analysis of the cells from H1 and H5 detected one I. indigotica chromosome and one or two chromosome terminal fragments. New B. napus types with phenotypic and genomic alterations were produced by H1 after pollination by B. napus and selfing for several generations, and by H5 after selfing. A progeny plant (2n = 20) was derived from H1 after pollination by I. indigotica twice and had a phenotype similar to a certain type of B. rapa, showing that hybrid H1 likely retained all chromosomes of the A genome and lost some of the C genome in parental B. napus. The reasons for the formation of the partial hybrids with unexpected chromosomal complements and for the chromosome elimination are discussed.

Patterns of genome duplication within the Brassica napus genome

Genome ◽  
2003 ◽  
Vol 46 (2) ◽  
pp. 291-303 ◽  
Author(s):  
I A.P Parkin ◽  
A G Sharpe ◽  
D J Lydiate
Keyword(s):  
Brassica Napus ◽  
Genome Duplication ◽  
Chromosomal Rearrangements ◽  
Centric Fusion ◽  
Linkage Groups ◽  
Gross Chromosomal Rearrangements ◽  
A Genome ◽  
C Genome ◽  
Homologous Locus ◽  
Duplicate Loci

The progenitor diploid genomes (A and C) of the amphidiploid Brassica napus are extensively duplicated with 73% of genomic clones detecting two or more duplicate sequences within each of the diploid genomes. This comprehensive duplication of loci is to be expected in a species that has evolved through a polyploid ancestor. The majority of the duplicate loci within each of the diploid genomes were found in distinct linkage groups as collinear blocks of linked loci, some of which had undergone a variety of rearrangements subsequent to duplication, including inversions and translocations. A number of identical rearrangements were observed in the two diploid genomes, suggesting they had occurred before the divergence of the two species. A number of linkage groups displayed an organization consistent with centric fusion and (or) fission, suggesting this mechanism may have played a role in the evolution of Brassica genomes. For almost every genetically mapped locus detected in the A genome a homologous locus was found in the C genome; the collinear arrangement of these homologous markers allowed the primary regions of homoeology between the two genomes to be identified. At least 16 gross chromosomal rearrangements differentiated the two diploid genomes during their divergence from a common ancestor.Key words: genome evolution, Brassicaeae, polyploidy, homoeologous linkage groups.

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.

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.

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.

SNP discovery by amplicon sequencing and multiplex SNP genotyping in the allopolyploid species Brassica napusThis article is one of a selection of papers from the conference “Exploiting Genome-wide Association in Oilseed Brassicas: a model for genetic improvement of major OECD crops for sustainable farming”.

Genome ◽  
2010 ◽  
Vol 53 (11) ◽  
pp. 948-956 ◽  
Author(s):  
G. Durstewitz ◽  
A. Polley ◽  
J. Plieske ◽  
H. Luerssen ◽  
E. M. Graner ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Oilseed Rape ◽  
Expressed Sequence Tag ◽  
Diploid Species ◽  
Amplicon Sequencing ◽  
Snp Markers ◽  
Snp Analysis ◽  
Genome Wide ◽  
A Genome ◽  
Illumina Goldengate

Oilseed rape ( Brassica napus ) is an allotetraploid species consisting of two genomes, derived from B. rapa (A genome) and B. oleracea (C genome). The presence of these two genomes makes single nucleotide polymorphism (SNP) marker identification and SNP analysis more challenging than in diploid species, as for a given locus usually two versions of a DNA sequence (based on the two ancestral genomes) have to be analyzed simultaneously during SNP identification and analysis. One hundred amplicons derived from expressed sequence tag (ESTs) were analyzed to identify SNPs in a panel of oilseed rape varieties and within two sister species representing the ancestral genomes. A total of 604 SNPs were identified, averaging one SNP in every 42 bp. It was possible to clearly discriminate SNPs that are polymorphic between different plant varieties from SNPs differentiating the two ancestral genomes. To validate the identified SNPs for their use in genetic analysis, we have developed Illumina GoldenGate assays for some of the identified SNPs. Through the analysis of a number of oilseed rape varieties and mapping populations with GoldenGate assays, we were able to identify a number of different segregation patterns in allotetraploid oilseed rape. The majority of the identified SNP markers can be readily used for genetic mapping, showing that amplicon sequencing and Illumina GoldenGate assays can be used to reliably identify SNP markers in tetraploid oilseed rape and to convert them into successful SNP assays that can be used for genetic analysis.

EVOLUTION OF AVENA SATIVA: ORIGIN OF THE CYTOPLASMIC GENOME

1976 ◽  
Vol 18 (4) ◽  
pp. 769-771 ◽  
Author(s):  
Martin W. Steer ◽  
Hugh Thomas
Keyword(s):  
Avena Sativa ◽  
Conclusive Evidence ◽  
Cytoplasmic Genome ◽  
A Genome ◽  
Isoelectric Points ◽  
C Genome

Comparisons of the isoelectric points of the large subunits from the enzyme ribulose biphosphate carboxylase, extracted from species and hybrids of Avena, provide conclusive evidence for the origin of the cytoplasmic genome of the hexapioid A. sativa L. from the A. genome diploids rather than the C genome diploids.

scholarly journals SINE jumping contributes to large-scale polymorphisms in the pig genomes

2021 ◽  
Author(s):  
Cai Chen ◽  
Enrico D'Alessandro ◽  
Eduard Murani ◽  
Yao Zheng ◽  
Domenico Giosa ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Population Genetic ◽  
Large Scale ◽  
Structural Variations ◽  
Population Genetic Analysis ◽  
Protein Coding ◽  
Pig Breeds ◽  
A Genome ◽  
Trait Locus ◽  
And Cluster Analysis

Abstract Background: Molecular markers based on retrotransposon insertion polymorphisms (RIPs) have been developed and are widely used in plants and animals. Short interspersed nuclear elements (SINEs) exert wide impacts on gene activity and even on phenotypes. However, SINE RIP profiles in livestock remain largely unknown, and not be revealed in pigs. Results: Our data revealed that SINEA1 displayed the most polymorphic insertions (22.5% intragenic and 26.5% intergenic), followed by SINEA2 (10.5% intragenic and 9% intergenic) and SINEA3 (12.5% intragenic and 5.0% intergenic). We developed a genome-wide SINE RIP mining protocol and obtained a large number of SINE RIPs (36,284), with over 80% accuracy and an even distribution in chromosomes (14.5/Mb), and 74.34% of SINE RIPs generated by SINEA1 element. Over 65% of pig SINE RIPs overlap with genes, with significant enrichment in the first and second introns of protein-coding and long non-coding RNA genes. Nearly half of the RIPs are common in these pig breeds. Sixteen SINE RIPs were applied for population genetic analysis in 23 pig breeds, the phylogeny tree and cluster analysis were generally consistent with the geographical distributions of native pig breeds in China. Conclusions: Our analysis revealed that SINEA1–3 elements, particularly SINEA1, are high polymorphic across different pig breeds, and generate large-scale structural variations in the pig genomes. And over 35, 000 SINE RIP markers were obtained. These data indicate that young SINE elements play important roles in creating new genetic variations and shaping the evolution of pig genome, and also provide strong evidences to support the great potential of SINE RIPs as genetic markers, which can be used for population genetic analysis and quantitative trait locus (QTL) mapping in pig.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

scholarly journals Genome-Wide Identification and Analysis of VQ Motif-containing Gene Family in Brassica napus and Functional Characterization of BnMKS1 in Response to Leptosphaeria maculans

2020 ◽  
Author(s):  
Zhongwei Zou ◽  
Fei Liu ◽  
Shuanglong Huang ◽  
DILANTHA GERARD FERNANDO
Keyword(s):  
Brassica Napus ◽  
Gene Family ◽  
Functional Characterization ◽  
Leptosphaeria Maculans ◽  
Defense Responses ◽  
Marker Genes ◽  
Blackleg Disease ◽  
Genome Wide ◽  
A Genome

Proteins containing Valine-glutamine (VQ) motifs play important roles in plant growth and development, as well as in defense responses to both abiotic and biotic stresses. Blackleg disease, which is caused by Leptosphaeria maculans, is the most important disease in canola (Brassica napus L.) worldwide. H; however, the identification of B. napus VQs and their functions in response to blackleg disease have not yet been reported. In this study, we conducted a genome genome-wide identification and characterization of the VQ gene family in B. napus, including chromosome location, phylogenetic relations, gene structure, motif domain, synteny analysis, and cis-elements categorization of their promoter regions. To understand B. napus VQ gene function in response to blackleg disease, we overexpressed BnVQ7 (BnaA01g36880D, also known as the mitogen-activated protein kinase4 substrate1 (MKS1) gene) in a blackleg-susceptible canola variety Westar. Overexpression The overexpression of BnMKS1 in canola did not improve its resistance to blackleg disease at the seedling stage. H; however, transgenic canola plants overexpressing BnMKS1 displayed an enhanced resistance to L. maculans infection at the adult plant stage. Expression levels of downstream and defense marker genes in cotyledons increased significantly at the necrotrophic stage of L. maculans infection in the overexpression line of BnMKS1, suggesting that the SA salicylic acid (SA)- and jasmonic acid (JA )-mediated signaling pathways were both involved in the defense responses. Together, these results suggest that BnMKS1 might play an important role in the defense against L. maculans.

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