Conserved patterns of chromosome pairing and recombination in Brassica napus crosses

The patterns of chromosome pairing and recombination in two contrasting Brassica napus F1 hybrids were deduced. One hybrid was from a winter oilseed rape (WOSR) × spring oilseed rape cross, the other from a resynthesized B. napus × WOSR cross. Segregation at 211 equivalent loci assayed in the population derived from each hybrid produced two collinear genetic maps. Alignment of the maps indicated that B. napus chromosomes behaved reproducibly as 19 homologous pairs and that the 19 distinct chromosomes of B. napus each recombined with unique chromosomes from the interspecific hybrid between Brassica rapa and Brassica oleracea. This result indicated that the genomes of the diploid progenitors of amphidiploid B. napus have remained essentially unaltered since the formation of the species and that the progenitor genomes were similar to those of modern-day B. rapa and B. oleracea. The frequency and distribution of crossovers were almost indistinguishable in the two populations, suggesting that the recombination machinery of B. napus could cope easily with different degrees of genetic divergence between homologous chromosomes. Efficient recombination in wide crosses will facilitate the introgression of novel alleles into oilseed rape from B. rapa and B. oleracea (via resynthesized B. napus) and reduce linkage drag.Key words: integrating genetic maps, microspore culture, segregation distortion, recombination frequency, locus distribution.

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Utilisation of doubled haploids in winter oilseed rape (Brassica napus L.) breeding

Czech Journal of Genetics and Plant Breeding ◽

10.17221/6110-cjgpb ◽

2012 ◽

Vol 38 (No. 1) ◽

pp. 50-54 ◽

Cited By ~ 3

Author(s):

V. Kučera ◽

M. Vyvadilová ◽

M. Klíma

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Doubled Haploid ◽

Microspore Culture ◽

Doubled Haploids ◽

Winter Oilseed Rape ◽

Brassica Napus L ◽

The Czech Republic ◽

Yield Parameters ◽

The World

A survey of development and prospects of the utilisation of doubled haploid techniques in rapeseed breeding in the world and in the Czech Republic is presented. The first utilisation of spontaneously occurred haploids from Brassica napus inbreeding programmes is described. The development of techniques of anther and later microspore culture is outlined. Special emphasis is given to the practical use of doubled haploids for the improvement of the effectiveness of breeding new productive cultivars. Some partial results of evaluation of yield parameters and resistance to important diseases in the obtained doubled haploid lines of winter oilseed rape are shown. The literary review and present results indicate, that the doubled haploid technique can be effectively used for the development of homozygous oilseed rape lines as an alternative to conventional methods.

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Farmers’ perspectives of future management of winter oilseed rape (Brassica napus L.): A case study from north-eastern Germany

European Journal of Agronomy ◽

10.1016/j.eja.2021.126350 ◽

2021 ◽

Vol 130 ◽

pp. 126350

Author(s):

Sabine Andert ◽

Andrea Ziesemer ◽

Han Zhang

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Winter Oilseed Rape ◽

Brassica Napus L ◽

Eastern Germany ◽

North Eastern ◽

Future Management

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PrBn, a Major Gene Controlling Homeologous Pairing in Oilseed Rape (Brassica napus) Haploids

Genetics ◽

10.1093/genetics/164.2.645 ◽

2003 ◽

Vol 164 (2) ◽

pp. 645-653 ◽

Cited By ~ 4

Author(s):

Eric Jenczewski ◽

Frédérique Eber ◽

Agnès Grimaud ◽

Sylvie Huet ◽

Marie Odile Lucas ◽

...

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Chromosome Pairing ◽

Major Gene ◽

Major Effect ◽

F1 Hybrids ◽

Precise Control ◽

Ph1 Locus ◽

Likelihood Approach ◽

Likelihood Ratio Statistics

Abstract Precise control of chromosome pairing is vital for conferring meiotic, and hence reproductive, stability in sexually reproducing polyploids. Apart from the Ph1 locus of wheat that suppresses homeologous pairing, little is known about the activity of genes that contribute to the cytological diploidization of allopolyploids. In oilseed rape (Brassica napus) haploids, the amount of chromosome pairing at metaphase I (MI) of meiosis varies depending on the varieties the haploids originate from. In this study, we combined a segregation analysis with a maximum-likelihood approach to demonstrate that this variation is genetically based and controlled mainly by a gene with a major effect. A total of 244 haploids were produced from F1 hybrids between a high- and a low-pairing variety (at the haploid stage) and their meiotic behavior at MI was characterized. Likelihood-ratio statistics were used to demonstrate that the distribution of the number of univalents among these haploids was consistent with the segregation of a diallelic major gene, presumably in a background of polygenic variation. Our observations suggest that this gene, named PrBn, is different from Ph1 and could thus provide complementary information on the meiotic stabilization of chromosome pairing in allopolyploid species.

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