Molecular-mapping analysis in Brassica napus using isozyme, RAPD and RFLP markers on a doubled-haploid progeny

Abstract A reciprocal chromosomal transposition was identified in several annual oilseed Brassica napus genotypes used as parents in crosses to biennial genotypes for genetic mapping studies. The transposition involved an exchange of interstitial homeologous regions on linkage groups N7 and N16, and its detection was made possible by the use of segregating populations of doubled haploid lines and codominant RFLP markers. RFLP probes detected pairs of homeologous loci on N7 and N16 for which the annual and biennial parents had identical alleles in regions expected to be homeologous. The existence of an interstitial reciprocal transposition was confirmed by cytological analysis of synaptonemal complexes of annual × biennial F1 hybrids. Although it included approximately one-third of the physical length of the N7 and N16 chromosomes, few recombination events within the region were recovered in the progenies of the hybrids. Significantly higher seed yields were associated with the parental configurations of the rearrangement in segregating progenies. These progenies contained complete complements of homeologous chromosomes from the diploid progenitors of B. napus, and thus their higher seed yields provide evidence for the selective advantage of allopolyploidy through the fixation of intergenomic heterozygosity.

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Genetics and molecular mapping of resistance to Plasmodiophora brassicae pathotypes 2, 3, 5, 6, and 8 in rutabaga (Brassica napus var. napobrassica)

Genome ◽

10.1139/gen-2016-0034 ◽

2016 ◽

Vol 59 (10) ◽

pp. 805-815 ◽

Cited By ~ 24

Author(s):

Muhammad Jakir Hasan ◽

Habibur Rahman

Keyword(s):

Brassica Napus ◽

Doubled Haploid ◽

Genetic Basis ◽

Molecular Mapping ◽

Plasmodiophora Brassicae ◽

Single Gene ◽

Genomic Region ◽

Clubroot Disease ◽

Dh Population ◽

Brassica Crops

Clubroot disease, caused by Plasmodiophora brassicae, is a threat to the production of Brassica crops including oilseed B. napus. In Canada, several pathotypes of this pathogen, such as pathotypes 2, 3, 5, 6, and 8, were identified, and resistance to these pathotypes was found in a rutabaga (B. napus var. napobrassica) genotype. In this paper, we report the genetic basis and molecular mapping of this resistance by use of F2, backcross (BC1), and doubled haploid (DH) populations generated from crossing of this rutabaga line to a susceptible spring B. napus canola line. The F1, F2, and BC1 populations were evaluated for resistance to pathotype 3, and the DH population was evaluated for resistance to pathotypes 2, 3, 5, 6, and 8. A 3:1 segregation in F2 and a 1:1 segregation in BC1 were found for resistance to pathotype 3, and a 1:1 segregation was found in the DH population for resistance to all pathotypes. Molecular mapping by using the DH population identified a genomic region on chromosome A8 carrying resistance to all five pathotypes. This suggests that a single gene or a cluster of genes, located in this genomic region, is involved in the control of resistance to these pathotypes.

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Molecular mapping of resistance to Leptosphaeria maculans in Australian cultivars of Brassica napus

Genome ◽

10.1139/g97-041 ◽

1997 ◽

Vol 40 (3) ◽

pp. 294-301 ◽

Cited By ~ 40

Author(s):

R. Mayerhofer ◽

A. G. Good ◽

V. K. Bansal ◽

M. R. Thiagarajah ◽

G. R. Stringam

Keyword(s):

Brassica Napus ◽

Molecular Mapping ◽

Bulked Segregant Analysis ◽

Leptosphaeria Maculans ◽

Rflp Markers ◽

Dh Population ◽

Dna Mapping ◽

Resistant Varieties ◽

Dh Lines ◽

Blackleg Fungus

Doubled haploid (DH) lines together with a cotyledon bioassay were employed for the molecular analysis of resistance to the blackleg fungus Leptosphaeria maculans in the Australian Brassica napus cultivars Shiralee and Maluka. We used bulked segregant analysis to identify 13 RAPD and two RFLP markers linked to the resistance phenotype and mapped these markers in the segregating DH population. Our data suggest the presence of a single major locus controlling resistance in the cultivar Shiralee, confirming our previous results obtained from Mendelian genetic analyses. In addition, preliminary mapping data for the cultivar Maluka also support a single locus model for resistance and indicate that the resistance genes from 'Shiralee' and 'Maluka' are either linked or possibly identical. The molecular markers identified in this study should be a useful tool for breeding blackleg resistant varieties using marker-assisted selection, and are the essential first step towards the map-based cloning of this resistance gene.Key words: blackleg, Leptosphaeria maculans, Brassica napus, DNA mapping, disease resistance.

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Application of trifluralin to embryogenic microspore cultures to generate doubled haploid plants in Brassica napus

Physiologia Plantarum ◽

10.1034/j.1399-3054.1995.950219.x ◽

1995 ◽

Vol 95 (2) ◽

pp. 304-309 ◽

Cited By ~ 1

Author(s):

Jiping Zhao ◽

Daina H. Simmonds

Keyword(s):

Brassica Napus ◽

Doubled Haploid ◽

Doubled Haploid Plants ◽

Haploid Plants

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Direct Modification of Multiple Gene Homoeologs in Brassica oleracea and Brassica napus Using Doubled Haploid Inducer‐Mediated Genome Editing System

Plant Biotechnology Journal ◽

10.1111/pbi.13632 ◽

2021 ◽

Author(s):

Chao Li ◽

Shifei Sang ◽

MengDan Sun ◽

Jin Yang ◽

YuQin Shi ◽

...

Keyword(s):

Brassica Napus ◽

Brassica Oleracea ◽

Genome Editing ◽

Doubled Haploid ◽

Multiple Gene ◽

Direct Modification ◽

Haploid Inducer

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Development of an agronomically superior blackleg resistant canola cultivar in Brassica napus L. using doubled haploidy

Canadian Journal of Plant Science ◽

10.4141/cjps95-072 ◽

1995 ◽

Vol 75 (2) ◽

pp. 437-439 ◽

Cited By ~ 12

Author(s):

G. R. Stringam ◽

V. K. Bansal ◽

M. R. Thiagarajah ◽

D. F. Degenhardt ◽

J. P. Tewari

Keyword(s):

Brassica Napus ◽

Doubled Haploid ◽

Leptosphaeria Maculans ◽

Resistance Breeding ◽

Breeding Method ◽

Brassica Napus L ◽

Breeding Lines ◽

University Of Alberta ◽

Blackleg Resistance ◽

The University

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus

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Molecular mapping of a thermosensitive genetic male sterility gene in rice using bulked segregant analysis

Genome ◽

10.1139/g97-027 ◽

1997 ◽

Vol 40 (2) ◽

pp. 188-194 ◽

Cited By ~ 59

Author(s):

P. K. Subudhi ◽

R. P. Borkakati ◽

S. S. Virmani ◽

N. Huang

Keyword(s):

Male Sterility ◽

Molecular Mapping ◽

Bulked Segregant Analysis ◽

Pcr Primers ◽

Rflp Markers ◽

Arbitrary Primers ◽

Repulsion Phase ◽

Genetic Male Sterility ◽

True Breeding ◽

Efficient Alternative

The thermosensitive genetic male sterility (TGMS) system is considered to be a more efficient alternative to the cytoplasmic male sterility (CMS) system for hybrid rice. An F2 population from a cross between a TGMS mutant line (IR32364TGMS) and IR68 was used to map the TGMS gene tms3(t). Fertile and sterile bulks were constructed following the classification of F2 plants into true breeding sterile, fertile, and segregating fertile plants based on F3 family studies. From the survey of 389 arbitrary primers in bulked segregant analysis, four RAPD markers were identified in which three, OPF182600, OPB19750, and OPAA7550, were linked to tms3(t) in repulsion phase and one, OPAC3640, was linked to tms3(t) in coupling phase. The tms3(t) gene was flanked by OPF182600 and OPAC3640 on one side and by OPAA7550 and OPB19750 on the other side. All four markers were low-copy sequences and two of them (OPF182600 and OPAC3640) detected polymorphism when the markers were used to probe the genomic blots. Subsequently, OPAC3640 was mapped to the short arm of chromosome 6 using a mapping population available at IRRI. However, no RFLP markers from this region showed linkage to tms3(t) owing to the lack of polymorphism between the parents. All RAPD fragments were cloned and partially sequenced from both ends. Thus, PCR primers can be designed to develop PCR markers for marker-assisted breeding to facilitate the transfer of tms3(t) from one genetic background to another.Key words: bulked segregant analysis, gene tagging, marker-assisted selection, RAPD, TGMS.

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